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• Any thoughts on how to create a true 'punch-out' area in a Sprite?

  - by rhtx

  I've been working on this for awhile, now. You might also call it a 'reverse mask', or an 'inverse mask'. Basically, I'm creating a view window within a display object. I need to allow objects on the stage that are under the window to be able to interact with the mouse. This is similar to a WPF question: http://stackoverflow.com/questions/740994/use-wpf-object-to-punch-hole-in-another, which has a much shorter write-up. I've got a Class called PunchOutShield, which creates a Sprite that covers the stage (or over some desired area). The Sprite's Graphics object is filled using the color and transparency of Flex's modal screen. The result is a screen that looks like the screen which appears behind a modal PopUp. PunchOutShield has a method called punch, which takes two arguments - the first is a Shape object, which defines the shape of the punch-through area; the second is a Point object, which indicates where to position the punch-through area. It took some experimenting, but I found that I can successfully create a punch-out area (i.e. - the modal screen does not display within the bounds of the given Shape). To do this, I set cacheAsBitmap to true on the Sprite that is used to create the modal screen, and also on the Shape object, which is added to the modal screen Sprite's displayList. If I set the blend mode of the Shape to ERASE, a completely transparent area is created in the modal screen. So far, great. The problem is that Shape does not subclass InteractiveObject, so there is no way to set mouseEnabled = false on it. And so, it prevents interaction between the mouse and any objects that are visible through the punch-out area. On top of that, InteractiveObject isn't available to look at, so I can't see if there is a way to borrow what it's doing to provide the mouseEnabled functionality and apply it to a subclass of Shape. I've tried using another Sprite object, rather than a Shape object, but the blending doesn't work out correctly. I'm not sure why there is a difference, but the Shape object seems to somehow combine with the parenting Sprite, allowing the ERASE blendMode to effect the desired punch-out visual appearance. It wouldn't be the end of the world if I had to draw up the screen with a series of rectangles so that the punch-out area was just simply not drawn, but that approach won't work if the punch-out area is complex. Or round. Any thoughts on this approach, or on an alternative approach?

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• How to created filtered reports in WPF?

  - by Michael Goyote

  Creating reports in WPF. I have two related tables. Table A-Customer: CustomerID(PK) Names Phone Number Customer Num Table B-Items: Products Price CustomerID I want to be able to generate a report like this: CustomerA Items Price Item A 10 Item B 10 Item C 10 --------------- Total 30 So this is what I have done: <Window x:Class="ReportViewerWPF.MainWindow" xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" xmlns:rv="clr-namespace:Microsoft.Reporting.WinForms; assembly=Microsoft.ReportViewer.WinForms" Title="Customer Report" Height="300" Width="400"> <Grid> <WindowsFormsHost Name="windowsFormsHost1"> <rv:ReportViewer x:Name="reportViewer1"/> </WindowsFormsHost> </Grid> Then I created a dataset and loaded the two tables, followed by a report wizard (dragged all the available fields and dropped them to the Values pane). The code behind the WPF window is this: public partial class CustomerReport : Window { public CustomerReport() { InitializeComponent(); _reportViewer.Load += ReportViewer_Load; } private bool _isReportViewerLoaded; private void ReportViewer_Load(object sender, EventArgs e) { if (!_isReportViewerLoaded) { Microsoft.Reporting.WinForms.ReportDataSource reportDataSource1 = new Microsoft.Reporting.WinForms.ReportDataSource(); HM2DataSet dataset = new HM2DataSet(); dataset.BeginInit(); reportDataSource1.Name = "DataSet";//This is the dataset name reportDataSource1.Value = dataset.CustomerTable; this.reportViewer1.LocalReport.DataSources.Add(reportDataSource1); this.reportViewer1.LocalReport.ReportPath = "../../Report3.rdlc"; dataset.EndInit(); HM2DataSetTableAdapters.CustomerTableAdapter funcTableAdapter = new HM2DataSetTableAdapters.CustomerTableAdapter(); funcTableAdapter.ClearBeforeFill = true; funcTableAdapter.Fill(dataset.CustomerTable); _reportViewer.RefreshReport(); _isReportViewerLoaded = true; } } As you might have guessed this loaded this list of customer with items and price: Customer Items Price Customer A Items A 10 Customer A Items B 10 Customer B Items D 10 Customer B Items C 10 How can I fine-tune this report to look like the one above, where the user can filter the customer he wants displayed on the report? Thanks in advance for the help. I would have preferred to use LINQ whenever filtering data

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• RadioButton checkedchanged event firing multiple times

  - by kash3

  Hi, I am trying to add multiple radiobutton columns to my gridview dynamically in the code and i want to implement some logic which involves database fetch in the checkedchanged event of radiobuttons but some how the checked changed event is being fired multiple times for each row. Following is the code: aspx: <asp:GridView ID="GridView1" runat="server" AutoGenerateColumns="False" BackColor="White" BorderColor="#CC9966" BorderStyle="None" EnableViewState="true" BorderWidth="1px" CellPadding="4" Font-Names="Verdana"> <FooterStyle BackColor="#FFFFCC" ForeColor="#330099" /> <Columns> <asp:TemplateField HeaderText="Select One"> <ItemTemplate> </ItemTemplate> </asp:TemplateField> <asp:TemplateField HeaderText="Select Two"> <ItemTemplate> </ItemTemplate> </asp:TemplateField> <asp:TemplateField> <ItemTemplate> <asp:Label ID="lblval" runat="server" Text="!" ForeColor="Red" Visible="false"/> </ItemTemplate> </asp:TemplateField> </Columns> **code behind** void GridView1_RowDataBound(object sender, GridViewRowEventArgs e) { if (e.Row.DataItem != null) { DataRowView dvRowview = (DataRowView)e.Row.DataItem; int currentRow = GridView1.Rows.Count; RadioButton rdoSelect1 = new RadioButton(); rdoSelect1.GroupName = "Select" + currentRow; rdoSelect1.ID = string.Concat("rdoSelect1", currentRow); rdoSelect1.AutoPostBack = true; rdoSelect1.CheckedChanged += new EventHandler(rdoSelect_CheckedChanged); e.Row.Cells[0].Controls.Add(rdoSelect1); RadioButton rdoSelect2 = new RadioButton(); rdoSelect2.GroupName = "Select" + currentRow; rdoSelect2.ID = string.Concat("rdoSelect2", currentRow); rdoSelect2.AutoPostBack = true; rdoSelect2.CheckedChanged += new EventHandler(rdoSelect_CheckedChanged); e.Row.Cells[1].Controls.Add(rdoSelect2); if (!IsPostBack) { e.Row.Cells[e.Row.Cells.Count - 1].Controls[1].Visible = false; if (e.Row.Cells[0] != null && Convert.ToBoolean(dvRowview["Select1"]) == true) rdoSelect1.Checked = true; else rdoSelect1.Checked = false; if (e.Row.Cells[0] != null && Convert.ToBoolean(dvRowview["Select2"]) == true) rdoSelect2.Checked = true; else rdoSelect2.Checked = false; } } } void rdoSelect_CheckedChanged(object sender, EventArgs e) { RadioButton rdoSelectedOption = (RadioButton)sender; GridViewRow selRow = rdoSelectedOption.NamingContainer as GridViewRow; if (rdoSelectedOption.Checked) selRow.Cells[selRow.Cells.Count - 1].Controls[1].Visible = true; else selRow.Cells[selRow.Cells.Count - 1].Controls[1].Visible = false; } i want the checkedchanged event to fire only once for a group name and row.

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• What is GC holes?

  - by tianyi

  I wrote a long TCP connection socket server in C#. Spike in memory in my server happens. I used dotNet Memory Profiler(a tool) to detect where the memory leaks. Memory Profiler indicates the private heap is huge, and the memory is something like below(the number is not real,what I want to show is the GC0 and GC2's Holes are very very huge, the data size is normal): Managed heaps - 1,500,000KB Normal heap - 1400,000KB Generation #0 - 600,000KB Data - 100,000KB "Holes" - 500,000KB Generation #1 - xxKB Data - 0KB "Holes" - xKB Generation #2 - xxxxxxxxxxxxxKB Data - 100,000KB "Holes" - 700,000KB Large heap - 131072KB Large heap - 83KB Overhead/unused - 130989KB Overhead - 0KB Howerver, what is GC hole? I read an article about the hole: http://kaushalp.blogspot.com/2007/04/what-is-gc-hole-and-how-to-create-gc.html The author said : The code snippet below is the simplest way to introduce a GC hole into the system. //OBJECTREF is a typedef for Object*. { PointerTable *pTBL = o_pObjectClass->GetPointerTable(); OBJECTREF aObj = AllocateObjectMemory(pTBL); OBJECTREF bObj = AllocateObjectMemory(pTBL); //WRONG!!! “aObj” may point to garbage if the second //“AllocateObjectMemory” triggered a GC. DoSomething (aOb, bObj); } All it does is allocate two managed objects, and then does something with them both. This code compiles fine, and if you run simple pre-checkin tests, it will probably “work.” But this code will crash eventually. Why? If the second call to “AllocateObjectMemory” triggers a GC, that GC discards the object instance you just assigned to “aObj”. This code, like all C++ code inside the CLR, is compiled by a non-managed compiler and the GC cannot know that “aObj” holds a root reference to an object you want kept live. ======================================================================== I can't understand what he explained. Does the sample mean aObj becomes a wild pointer after GC? Is it mean { aObj = (*aObj)malloc(sizeof(object)); free(aObj); function(aObj);? } ? I hope somebody can explain it.

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• Codeigniter not returning me to upload form after image upload.

  - by Drew

  I'm still very new to codeigniter. The issue i'm having is that the file uploads fine and it writes to the database without issue but it just doesn't return me to the upload form. Instead it stays in the do_upload and doesn't display anything. Even more bizarrely there is some source code behind the scenes. Can someone tell my what it is i'm doing wrong because I want to be returning to my upload form after submission. Thanks in advance. Below is my code: Controller: function do_upload() { if($this->Upload_model->do_upload()) { $this->load->view('home/upload_form'); }else{ $this->load->view('home/upload_success', $error); } } Model: function do_upload() { $config['upload_path'] = './uploads/'; $config['allowed_types'] = 'gif|jpg|png'; $config['max_size'] = '2000'; $this->load->library('upload', $config); if ( ! $this->upload->do_upload()) { $error = array('error' => $this->upload->display_errors()); return $error; } else { $data = $this->upload->data(); $full_path = 'uploads/' . $data['file_name']; $spam = array( 'image_url' => $full_path, 'url' => $this->input->post('url') ); $id = $this->input->post('id'); $this->db->where('id', $id); $this->db->update('NavItemData', $spam); return true; } } View (called upload_form): <html> <head> <title>Upload Form</title> </head> <body> <?php if(isset($buttons)) : foreach($buttons as $row) : ?> <h2><?php echo $row->image_url; ?></h2> <p><?php echo $row->url; ?></p> <p><?php echo $row->name; ?></p> <p><?php echo anchor("upload/update_nav/$row->id", 'edit'); ?></p> <?php endforeach; ?> <?php endif; ?> </body> </html>

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• Template function as a template argument

  - by Kos

  I've just got confused how to implement something in a generic way in C++. It's a bit convoluted, so let me explain step by step. Consider such code: void a(int) { // do something } void b(int) { // something else } void function1() { a(123); a(456); } void function2() { b(123); b(456); } void test() { function1(); function2(); } It's easily noticable that function1 and function2 do the same, with the only different part being the internal function. Therefore, I want to make function generic to avoid code redundancy. I can do it using function pointers or templates. Let me choose the latter for now. My thinking is that it's better since the compiler will surely be able to inline the functions - am I correct? Can compilers still inline the calls if they are made via function pointers? This is a side-question. OK, back to the original point... A solution with templates: void a(int) { // do something } void b(int) { // something else } template<void (*param)(int) > void function() { param(123); param(456); } void test() { function<a>(); function<b>(); } All OK. But I'm running into a problem: Can I still do that if a and b are generics themselves? template<typename T> void a(T t) { // do something } template<typename T> void b(T t) { // something else } template< ...param... > // ??? void function() { param<SomeType>(someobj); param<AnotherType>(someotherobj); } void test() { function<a>(); function<b>(); } I know that a template parameter can be one of: a type, a template type, a value of a type. None of those seems to cover my situation. My main question is hence: How do I solve that, i.e. define function() in the last example? (Yes, function pointers seem to be a workaround in this exact case - provided they can also be inlined - but I'm looking for a general solution for this class of problems).

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• Problem with continue in While Loop within Try/Catch in C# (2.0)

  - by csharpnoob

  Hi, when i try to use in my ASPX Webpage in the Code Behind this try{ while() { ... db.Open(); readDataMoney = new OleDbCommand("SELECT * FROM Customer WHERE card = '" + customer.card + "';", db).ExecuteReader(); while (readDataMoney.Read()) { try { if (!readDataMoney.IsDBNull(readDataMoney.GetOrdinal("Credit"))) { customer.credit = Convert.ToDouble(readDataMoney[readDataMoney.GetOrdinal("Credit")]); } if (!readDataMoney.IsDBNull(readDataMoney.GetOrdinal("Bonus"))) { customer.bonus = Convert.ToDouble(readDataMoney[readDataMoney.GetOrdinal("Bonus")]); } } catch (Exception ex) { Connector.writeLog("Money: " + ex.StackTrace + "" + ex.Message + "" + ex.Source); customer.credit = 0.0; customer.credit = 0.0; continue; } finally { } } readDataMoney.Close(); vsiDB.Close(); ... } }catch { continue; } The whole page hangs if there is a problem when the read from db isn't working. I tried to check for !isNull, but same problem. I have a lots of differend MDB Files to process, which are readonly (can't repair/compact) and some or others not. Same Design/Layout of Tables. With good old ASP Classic 3.0 all of them are processing with the "On Resume Next". I know I know. But that's how it is. Can't change the source. So the basic question: So is there any way to tell .NET to continue the loop whatever happens within the try loop if there is any exception? After a lots of wating time i get this exceptions: at System.Data.Common.UnsafeNativeMethods.IDBInitializeInitialize.Invoke(IntPtr pThis) at System.Data.OleDb.DataSourceWrapper.InitializeAndCreateSession(OleDbConnectionString constr, SessionWrapper& sessionWrapper) at System.Data.OleDb.OleDbConnectionInternal..ctor(OleDbConnectionString constr, OleDbConnection connection) at System.Data.OleDb.OleDbConnectionFactory.CreateConnection(DbConnectionOptions options, Object poolGroupProviderInfo, DbConnectionPool pool, DbConnection owningObject) at System.Data.ProviderBase.DbConnectionFactory.CreateNonPooledConnection(DbConnection owningConnection, DbConnectionPoolGroup poolGroup) at System.Data.ProviderBase.DbConnectionFactory.GetConnection(DbConnection owningConnection) at System.Data.ProviderBase.DbConnectionClosed.OpenConnection(DbConnection outerConnection, DbConnectionFactory connectionFactory) at System.Data.OleDb.OleDbConnection.Open() at GetCustomer(String card)Thread was being aborted.System.Data and System.Runtime.InteropServices.Marshal.ReadInt16(IntPtr ptr, Int32 ofs) System.Data.ProviderBase.DbBuffer.ReadInt16(Int32 offset) System.Data.OleDb.ColumnBinding.Value_I2() System.Data.OleDb.ColumnBinding.Value() System.Data.OleDb.OleDbDataReader.GetValue(Int32 ordinal) System.Data.OleDb.OleDbDataReader.get_Item(Int32 index) Thread was terminated.mscorlib Thanks for any help.

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• asp.net Web server control with child controls, event not firing

  - by bleeeah

  I have a simple web control (TaskList) that can have children (Task) which inherit from LinkButton, that can be added declaratively or programatically. This works ok, but I can't get the onclick event of a Task to be fired in my code behind. The code .. [ToolboxData("<{0}:TaskList runat=\"server\"> </{0}:TaskList>")] [ParseChildren(true)] [PersistChildren(false)] public class TaskList : System.Web.UI.Control { //[DefaultProperty("Text")] public TaskList() {} private List<Task> _taskList = new List<Task>(); private string _taskHeading = ""; public string Heading { get { return this._taskHeading; } set { this._taskHeading = value; } } [NotifyParentProperty(true)] [PersistenceMode(PersistenceMode.InnerProperty)] [DesignerSerializationVisibility(DesignerSerializationVisibility.Content)] public List<Task> Tasks { get { return this._taskList; } set { this._taskList = value; } } protected override void CreateChildControls() { foreach (Task task in this._taskList) this.Controls.Add(task); base.CreateChildControls(); } protected override void Render(HtmlTextWriter writer) { writer.Write("<h2>" + this._taskHeading + "</h2>"); writer.Write("<div class='tasks_container'>"); writer.Write("<div class='tasks_list'>"); writer.Write("<ul>"); foreach (Task task in this._taskList) { writer.Write("<li>"); task.RenderControl(writer); writer.Write("</li>"); } writer.Write("</ul>"); writer.Write("</div>"); writer.Write("</div>"); } } public class Task : LinkButton { private string _key = ""; public string Key { get { return this._key; } set { this._key = value; } } } Markup: <rf:TaskList runat="server" ID="tskList" Heading="Tasks"> <Tasks> <rf:Task Key="ba" ID="L1" Text="Helllo" OnClick="task1_Click" runat="server" /> </Tasks> </rf:TaskList> The Onclick event task1_Click never fires when clicked (although a postback occurs).

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• What's the C strategy to "imitate" a C++ template ?

  - by Andrei Ciobanu

  After reading some examples on stackoverflow, and following some of the answers for my previous questions (1), I've eventually come with a "strategy" for this. I've come to this: 1) Have a declare section in the .h file. Here I will define the data-structure, and the accesing interface. Eg.: /** * LIST DECLARATION. (DOUBLE LINKED LIST) */ #define NM_TEMPLATE_DECLARE_LIST(type) \ typedef struct nm_list_elem_##type##_s { \ type data; \ struct nm_list_elem_##type##_s *next; \ struct nm_list_elem_##type##_s *prev; \ } nm_list_elem_##type ; \ typedef struct nm_list_##type##_s { \ unsigned int size; \ nm_list_elem_##type *head; \ nm_list_elem_##type *tail; \ int (*cmp)(const type e1, const type e2); \ } nm_list_##type ; \ \ nm_list_##type *nm_list_new_##type##_(int (*cmp)(const type e1, \ const type e2)); \ \ (...other functions ...) 2) Wrap the functions in the interface inside MACROS: /** * LIST INTERFACE */ #define nm_list(type) \ nm_list_##type #define nm_list_elem(type) \ nm_list_elem_##type #define nm_list_new(type,cmp) \ nm_list_new_##type##_(cmp) #define nm_list_delete(type, list, dst) \ nm_list_delete_##type##_(list, dst) #define nm_list_ins_next(type,list, elem, data) \ nm_list_ins_next_##type##_(list, elem, data) (...others...) 3) Implement the functions: /** * LIST FUNCTION DEFINITIONS */ #define NM_TEMPLATE_DEFINE_LIST(type) \ nm_list_##type *nm_list_new_##type##_(int (*cmp)(const type e1, \ const type e2)) \ {\ nm_list_##type *list = NULL; \ list = nm_alloc(sizeof(*list)); \ list->size = 0; \ list->head = NULL; \ list->tail = NULL; \ list->cmp = cmp; \ }\ void nm_list_delete_##type##_(nm_list_##type *list, \ void (*destructor)(nm_list_elem_##type elem)) \ { \ type data; \ while(nm_list_size(list)){ \ data = nm_list_rem_##type(list, tail); \ if(destructor){ \ destructor(data); \ } \ } \ nm_free(list); \ } \ (...others...) In order to use those constructs, I have to create two files (let's call them templates.c and templates.h) . In templates.h I will have to NM_TEMPLATE_DECLARE_LIST(int), NM_TEMPLATE_DECLARE_LIST(double) , while in templates.c I will need to NM_TEMPLATE_DEFINE_LIST(int) , NM_TEMPLATE_DEFINE_LIST(double) , in order to have the code behind a list of ints, doubles and so on, generated. By following this strategy I will have to keep all my "template" declarations in two files, and in the same time, I will need to include templates.h whenever I need the data structures. It's a very "centralized" solution. Do you know other strategy in order to "imitate" (at some point) templates in C++ ? Do you know a way to improve this strategy, in order to keep things in more decentralized manner, so that I won't need the two files: templates.c and templates.h ?

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• Little CSS problem with Auto height and nested div's

  - by GeekDrop.com

  So I'm finally learning my way around CSS more and have run into a small problem. I have a container div, with a few divs inside of it, one of them is a bit if text (which can be a random height) and an image that will have a MAX height of 200px. I am using a dotted/colored background behind them that needs to auto expand to the height of whichever is the tallest, either the text or the image. Right now when i use height:auto on the container div it works perfect for the random height text: Example Screenshot But it's only adjusting according to the text's height; if the image is taller than the text, the image overflows the bottom of the background dotted/colored box. Example Screenshot The CSS I'm using currently is this: h1 div#like_detailed { margin: 0; font-size: 1.1em; width: 700px; } #details-image img { border: none; clear: left; float: right; margin: -45px 0 0 0; max-height: 200px; padding: 0 7px 0 10px; } #deets-container { background-color: #FEF; border: #190AE7 1px dotted; height: auto; margin-top: 0; margin-bottom: 30px; padding-top: 10px; padding-right: 10px; padding-left: 10px; padding-bottom: 0; } And the HTML for it is this: <div id="deets-container" class="rounded"> <!-- Button --> <div class="likebtnframe">(some code)</div> <!-- Button --> <div class="tweetbtnframe">(some code)</div> <!-- Button --> <ul id="share"> <li><a name="share">(some code)</a></li> </ul> <!-- Submitted By --> <div class="submitter_detailed"><span class="submitter-color smalltext">(some code)</span> (some code)</div> <!-- Image --> <div id="**details-image**">(some code)</div> <!-- Like / Quote --> <h1 id="**like_detailed**">(some code)</h1> </div> I have a feeling this is pretty easy but I'm running out of time to sort it out on my own. Anyone?

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• DataTriggered animation is triggered only in the first time

  - by Pavel

  I just wanted to create very simple example of DataTriggers and animation. Two checkboxes and Rectangle. Checking the first cb makes the rectangle fade away. (CodeBehind var is true) Checking the second cb makes the rectangle come back. (var is false) App is loading - the rectangle is showing (true) Firs cb is checked by default. I'm checking second cb - rect is dissapearing. It's OK. But when I then check the first cb rect isn't showing up. But checking the second cb still makes rect show up and fade away. here's my xaml and code behind: <StackPanel> <RadioButton IsChecked="True" Checked="RadioButton_Checked"></RadioButton> <RadioButton Checked="RadioButton_Checked_1"></RadioButton> <Rectangle Name="r1" Width="100" Height="300" Fill="Green"> <Rectangle.Style> <Style TargetType="Rectangle"> <Style.Triggers> <DataTrigger Binding="{Binding Active}" Value="True"> <DataTrigger.EnterActions> <BeginStoryboard> <Storyboard> <DoubleAnimation Storyboard.TargetProperty="Opacity" From="0" To="1" Duration="0:0:1" /> </Storyboard> </BeginStoryboard> </DataTrigger.EnterActions> </DataTrigger> <DataTrigger Binding="{Binding Active}" Value="False"> <DataTrigger.EnterActions> <BeginStoryboard> <Storyboard> <DoubleAnimation Storyboard.TargetProperty="Opacity" From="1" To="0" Duration="0:0:1" /> </Storyboard> </BeginStoryboard> </DataTrigger.EnterActions> </DataTrigger> </Style.Triggers> </Style> </Rectangle.Style> </Rectangle> </StackPanel> public bool Active { get { return (bool) GetValue(ActiveProperty); } set { SetValue(ActiveProperty, value); } } public static readonly DependencyProperty ActiveProperty = DependencyProperty.Register("Active", typeof(bool), typeof(MainWindow), new UIPropertyMetadata(false)); private void RadioButton_Checked(object sender, RoutedEventArgs e) { Active = true; } private void RadioButton_Checked_1(object sender, RoutedEventArgs e) { Active = false; }

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• C# Serialization Surrogate - Cannot access a disposed object

  - by crushhawk

  I have an image class (VisionImage) that is a black box to me. I'm attempting to serialize the image object to file using Serialization Surrogates as explained on this page. Below is my surrogate code. sealed class VisionImageSerializationSurrogate : ISerializationSurrogate { public void GetObjectData(Object obj, SerializationInfo info, StreamingContext context) { VisionImage image = (VisionImage)obj; byte[,] temp = image.ImageToArray().U8; info.AddValue("width", image.Width); info.AddValue("height", image.Height); info.AddValue("pixelvalues", temp, temp.GetType()); } public Object SetObjectData(Object obj, SerializationInfo info, StreamingContext context, ISurrogateSelector selector) { VisionImage image = (VisionImage)obj; Int32 width = info.GetInt32("width"); Int32 height = info.GetInt32("height"); byte[,] temp = new byte[height, width]; temp = (byte[,])info.GetValue("pixelvalues", temp.GetType()); PixelValue2D tempPixels = new PixelValue2D(temp); image.ArrayToImage(tempPixels); return image; } } I've stepped through it to write to binary. It seems to be working fine (file is getting bigger as the images are captured). I tried to test it read the file back in. The values read back in are correct as far as the "info" object is concerned. When I get to the line image.ArrayToImage(tempPixels); It throws the "Cannot access a disposed object" exception. Upon further inspection, the object and the resulting image are both marked as disposed. My code behind the form spawns an "acquisitionWorker" and runs the following code. void acquisitionWorker_LoadImages(object sender, DoWorkEventArgs e) { // This is the main function of the acquisition background worker thread. // Perform image processing here instead of the UI thread to avoid a // sluggish or unresponsive UI. BackgroundWorker worker = (BackgroundWorker)sender; try { uint bufferNumber = 0; // Loop until we tell the thread to cancel or we get an error. When this // function completes the acquisitionWorker_RunWorkerCompleted method will // be called. while (!worker.CancellationPending) { VisionImage savedImage = (VisionImage) formatter.Deserialize(fs); CommonAlgorithms.Copy(savedImage, imageViewer.Image); // Update the UI by calling ReportProgress on the background worker. // This will call the acquisition_ProgressChanged method in the UI // thread, where it is safe to update UI elements. Do not update UI // elements directly in this thread as doing so could result in a // deadlock. worker.ReportProgress(0, bufferNumber); bufferNumber++; } } catch (ImaqException ex) { // If an error occurs and the background worker thread is not being // cancelled, then pass the exception along in the result so that // it can be handled in the acquisition_RunWorkerCompleted method. if (!worker.CancellationPending) e.Result = ex; } } What am I missing here? Why would the object be immediately disposed?

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• What is the best practice to segment c#.net projects based on a single base project

  - by Anthony

  Honestly, I can't word my question any better without describing it. I have a base project (with all its glory, dlls, resources etc) which is a CMS. I need to use this project as a base for othe custom bake projects. This base project is to be maintained and updated among all custom bake projects. I use subversion (Collabnet and Tortise SVN) I have two questions: 1 - Can I use subversion to share the base project among other projects What I mean here is can I "Checkout" the base project into another "Checked Out" project and have both update and commit seperatley. So, to paint a picture, let's say I am working on a custom project and I modify the core/base prject in some way (which I know will suit the others) can I then commit those changes and upon doing so when I update the base project in the other "Checked out" resources will it pull the changes? In short, I would like not to have to manually deploy updated core files whenever I make changes into each seperate project. 2 - If I create a custom file (let's say an webcontrol or aspx page etc) can I have it compile seperatley from the base project Another tricky one to explain. When I publish my web application it creates DLLs based on the namespaces of projects attached to it. So I may have a number of DLLs including the "Website's" namespace DLL, which could simply be website. I want to be able to make a seperate, custom, control which does not compile into those DLLs as the custom files should not rely on those DLLS to run. Is it as simple to set a seperate namespace for those files like CustomFiles.ProjectName for example? Think of the whole idea as adding modules to the .NET project, I don't want the module's code in any of the core DLLs but I do need for module to be able to access the core dlls. (There is no need for the core project to access the module code as it should be one way only in theory, though I reckon it woould not be possible anyway without using JSON/SOAP or something like that, maybe I am wrong.) I want to create a pluggable environment much like that of Joomla/Wordpress as since PHP generally doesn't have to be compiled first I see this is the reason why all this is possible/easy. The idea is to allow pluggable themes, modules etc etc. (I haven't tried simply adding .NET themes after compile/publish but I am assuming this is possible anyway? OR does the compiler need to reference items in the files?)

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• Recommended ASP.NET Shared Hosting

  - by coffeeaddict

  Ok, I have to admit I'm getting fed up with www.discountasp.net's pricing model and this annoyance has built up over the past 8 years or so. I've been with them for years and absolutely love them on the technical side, however it's getting ridiculously expensive for so little that you get. I mean here's my scenario: 1) I am running 2 SQL Server databases which costs me $10/ea per month so that's $20/month for 2 and I only get 500 mb disk space which is horrible 2) I am paying $10/mo just for the hosting itself which I only get 1 gig of disk space! I mean common! 3) I am simply running 2 small apps (Screwturn Wiki & Subtext Blog)...so I don't really care if it's up 99% or not, it's not worth paying a total of $300 just to keep these 2 apps running over discountasp.net Anyone else feel the same? Yes, I know they have great support, probably have great servers running behind this but in the end I really don't care as long as my site is up 95% or better. Yes, the hosting toolset rocks. But you know I bet you I can find a similar set somewhere else. I like how I can totally control IIS 7 at discountasp and I can control my own app pool etc. That's very powerful and essential. But anyone have any good alternatives to discountasp that gives me close to the same at a much more reasonable cost point? I mean http://www.m6.net/prices.aspx gives you 10 SQL Databases for $7 and 200 gigs disk space! I don't know about their tools or support but just looking at those numbers and some other hosts I've seen, I feel that discountasp.net is way out of line. They don't even offer any purchasing discounts such as it would be nice if my 2nd SQL Server is only $5/month not $10...stuff like this, to make it much more realistic and fair. Opinions (people who do have discountasp.net, people who have left them, or people who have another host they like)??? But geez $300 just to host a couple DBs and lightweight open source apps? Not worth the price they are charging. I'm almost at a price point that enables me to get a decent dedicated server! I really don't care about beta support. Not a big deal to me.

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• How to pass operators as parameters

  - by Rodion Ingles

  I have to load an array of doubles from a file, multiply each element by a value in a table (different values for different elements), do some work on it, invert the multiplication (that is, divide) and then save the data back to file. Currently I implement the multiplication and division process in two separate methods. Now there is some extra work behind the scenes but apart from the specific statements where the multiplication/division occurs, the rest of the code is identical. As you can imagine, with this approach you have to be very careful making any changes. The surrounding code is not trivial, so its either a case of manually editing each method or copying changes from one method to the other and remembering to change the * and / operators. After too many close calls I am fed up of this and would like to make a common function which implements the common logic and two wrapper functions which pass which operator to use as a parameter. My initial approach was to use function pointers: MultiplyData(double data) { TransformData(data, &(operator *)); } DivideData(double data) { TransformData(data, &(operator /)); } TransformData(double data, double (*func)(double op1, double op2)) { /* Do stuff here... */ } However, I can't pass the operators as pointers (is this because it is an operator on a native type?), so I tried to use function objects. Initially I thought that multiplies and divides functors in <functional> would be ideal: MultiplyData(double data) { std::multiplies<double> multFunct; TransformData(data, &multFunct); } DivideData(double data) { std::divides<double> divFunct; TransformData(data, &divFunct); } TransformData(double data, std::binary_function<double, double, double> *funct) { /* Do stuff here... */ } As you can see I was trying to use a base class pointer to pass the functor polymorphically. The problem is that std::binary_function does not declare an operator() member for the child classes to implement. Is there something I am missing, or is the solution to implement my own functor heirarchy (which really seems more trouble than it is worth)?

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• template pass by const reference

  - by 7vies

  Hi, I've looked over a few similar questions, but I'm still confused. I'm trying to figure out how to explicitly (not by compiler optimization etc) and C++03-compatible avoid copying of an object when passing it to a template function. Here is my test code: #include <iostream> using namespace std; struct C { C() { cout << "C()" << endl; } C(const C&) { cout << "C(C)" << endl; } ~C() { cout << "~C()" << endl; } }; template<class T> void f(T) { cout << "f<T>" << endl; } template<> void f(C c) { cout << "f<C>" << endl; } // (1) template<> void f(const C& c) { cout << "f<C&>" << endl; } // (2) int main() { C c; f(c); return 0; } (1) accepts the object of type C, and makes a copy. Here is the output: C() C(C) f<C> ~C() ~C() So I've tried to specialize with a const C& parameter (2) to avoid this, but this simply doesn't work (apparently the reason is explained in this question). Well, I could "pass by pointer", but that's kind of ugly. So is there some trick that would allow to do that somehow nicely? EDIT: Oh, probably I wasn't clear. I already have a templated function template<class T> void f(T) {...} But now I want to specialize this function to accept a const& to another object: template<> void f(const SpecificObject&) {...} But it only gets called if I define it as template<> void f(SpecificObject) {...}

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• Use format strings that contain %1, %2 etc. instead of %d, %s etc. - Linux, C++

  - by rursw1

  Hello, As a follow-up of this question (Message compiler replacement in Linux gcc), I have the following problem: When using MC.exe on Windows for compiling and generating messages, within the C++ code I call FormatMessage, which retrieves the message and uses the va_list *Arguments parameter to send the varied message arguments. For example: messages.mc file: MessageId=1 Severity=Error SymbolicName=MULTIPLE_MESSAGE_OCCURED Language=English message %1 occured %2 times. . C++ code: void GetMsg(unsigned int errCode, wstring& message,unsigned int paramNumber, ...) { HLOCAL msg; DWORD ret; LANGID lang = GetUserDefaultLangID(); try { va_list argList; va_start( argList, paramNumber ); const TCHAR* dll = L"MyDll.dll"; _hModule = GetModuleHandle(dll); ret =::FormatMessage( FORMAT_MESSAGE_ALLOCATE_BUFFER | FORMAT_MESSAGE_FROM_HMODULE|FORMAT_MESSAGE_IGNORE_INSERTS, _hModule, errCode, lang, (LPTSTR) &msg, 0, &argList ); if ( 0 != ret ) { unsigned int count = 0 ; message = msg; if (paramNumber>0) { wstring::const_iterator iter; for (iter = message.begin();iter!=message.end();iter++) { wchar_t xx = *iter; if (xx ==L'%') count++; } } if ((count == paramNumber) && (count >0)) { ::LocalFree( msg ); ret =::FormatMessage( FORMAT_MESSAGE_ALLOCATE_BUFFER | FORMAT_MESSAGE_FROM_HMODULE, _hModule, errCode, GetUserDefaultLangID(), (LPTSTR) &msg, 0, &argList ); } else if (count != paramNumber) { wstringstream tmp; wstring messNumber; tmp << (errCode & 0xFFFF); tmp >> messNumber; message = message +L"("+ messNumber + L"). Bad Format String. "; } } ::LocalFree( msg ); } catch (...) { message << L"last error: " << GetLastError(); } va_end( argList ); } Caller code: wstring message; GetMsg(MULTIPLE_MESSAGE_OCCURED, message,2, "Error message", 5); Now, I wrote a simple script to generate a .msg file from the .mc file, and then I use gencat to generate a catalog from it. But is there a way to use the formatted strings as they contain %1, %2, etc. and NOT the general (%d, %s...) format? Please note, that the solution has to be generic enough for each possible message with each posible types\ arguments order... Is it possible at all? Thank you.

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• I need help converting a C# string from one character encoding to another?

  - by Handleman

  According to Spolsky I can't call myself a developer, so there is a lot of shame behind this question... Scenario: From a C# application, I would like to take a string value from a SQL db and use it as the name of a directory. I have a secure (SSL) FTP server on which I want to set the current directory using the string value from the DB. Problem: Everything is working fine until I hit a string value with a "special" character - I seem unable to encode the directory name correctly to satisfy the FTP server. The code example below uses "special" character é as an example uses WinSCP as an external application for the ftps comms does not show all the code required to setup the Process "_winscp". sends commands to the WinSCP exe by writing to the process standardinput for simplicity, does not get the info from the DB, but instead simply declares a string (but I did do a .Equals to confirm that the value from the DB is the same as the declared string) makes three attempts to set the current directory on the FTP server using different string encodings - all of which fail makes an attempt to set the directory using a string that was created from a hand-crafted byte array - which works Process _winscp = new Process(); byte[] buffer; string nameFromString = "Sinéad O'Connor"; _winscp.StandardInput.WriteLine("cd \"" + nameFromString + "\""); buffer = Encoding.UTF8.GetBytes(nameFromString); _winscp.StandardInput.WriteLine("cd \"" + Encoding.UTF8.GetString(buffer) + "\""); buffer = Encoding.ASCII.GetBytes(nameFromString); _winscp.StandardInput.WriteLine("cd \"" + Encoding.ASCII.GetString(buffer) + "\""); byte[] nameFromBytes = new byte[] { 83, 105, 110, 130, 97, 100, 32, 79, 39, 67, 111, 110, 110, 111, 114 }; _winscp.StandardInput.WriteLine("cd \"" + Encoding.Default.GetString(nameFromBytes) + "\""); The UTF8 encoding changes é to 101 (decimal) but the FTP server doesn't like it. The ASCII encoding changes é to 63 (decimal) but the FTP server doesn't like it. When I represent é as value 130 (decimal) the FTP server is happy, except I can't find a method that will do this for me (I had to manually contruct the string from explicit bytes). Anyone know what I should do to my string to encode the é as 130 and make the FTP server happy and finally elevate me to level 1 developer by explaining the only single thing a developer should understand?

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• WP7 databinding displays int but not string?

  - by user1794106

  Whenever I test my app.. it binds the data from Note class and displays it if it isn't a string. But for the string variables it wont bind. What am I doing wrong? Inside my main: <Grid x:Name="ContentPanel" Grid.Row="1" Margin="12,0,12,0"> <ListBox x:Name="Listbox" SelectionChanged="listbox_SelectionChanged" ItemsSource="{Binding}"> <ListBox.ItemTemplate> <DataTemplate> <Border Width="800" MinHeight="60"> <StackPanel> <TextBlock x:Name="Title" VerticalAlignment="Center" FontSize="{Binding TextSize}" Text="{Binding Name}"/> <TextBlock x:Name="Date" VerticalAlignment="Center" FontSize="{Binding TextSize}" Text="{Binding Modified}"/> </StackPanel> </Border> </DataTemplate> </ListBox.ItemTemplate> </ListBox> </Grid> </Grid> in code behind: protected override void OnNavigatedTo(System.Windows.Navigation.NavigationEventArgs e) { MessageBox.Show("enters onNav Main"); DataContext = null; DataContext = Settings.NotesList; Settings.CurrentNoteIndex = -1; Listbox.SelectedIndex = -1; if (Settings.NotesList != null) { if (Settings.NotesList.Count == 0) { Notes.Text = "No Notes"; } else { Notes.Text = ""; } } } and public static class Settings { public static ObservableCollection<Note> NotesList; static IsolatedStorageSettings settings; private static int currentNoteIndex; static Settings() { NotesList = new ObservableCollection<Note>(); settings = IsolatedStorageSettings.ApplicationSettings; MessageBox.Show("enters constructor settings"); } notes class: public class Note { public DateTimeOffset Modified { get; set; } public string Title { get; set; } public string Content { get; set; } public int TextSize { get; set; } public Note() { MessageBox.Show("enters Note Constructor"); Modified = DateTimeOffset.Now; Title = "test"; Content = "test"; TextSize = 32; } }

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• C++ include statement required if defining a map in a headerfile.

  - by Justin

  I was doing a project for computer course on programming concepts. This project was to be completed in C++ using Object Oriented designs we learned throughout the course. Anyhow, I have two files symboltable.h and symboltable.cpp. I want to use a map as the data structure so I define it in the private section of the header file. I #include <map> in the cpp file before I #include "symboltable.h". I get several errors from the compiler (MS VS 2008 Pro) when I go to debug/run the program the first of which is: Error 1 error C2146: syntax error : missing ';' before identifier 'table' c:\users\jsmith\documents\visual studio 2008\projects\project2\project2\symboltable.h 22 Project2 To fix this I had to #include <map> in the header file, which to me seems strange. Here are the relevant code files: // symboltable.h #include <map> class SymbolTable { public: SymbolTable() {} void insert(string variable, double value); double lookUp(string variable); void init(); // Added as part of the spec given in the conference area. private: map<string, double> table; // Our container for variables and their values. }; and // symboltable.cpp #include <map> #include <string> #include <iostream> using namespace std; #include "symboltable.h" void SymbolTable::insert(string variable, double value) { table[variable] = value; // Creates a new map entry, if variable name already exist it overwrites last value. } double SymbolTable::lookUp(string variable) { if(table.find(variable) == table.end()) // Search for the variable, find() returns a position, if thats the end then we didnt find it. throw exception("Error: Uninitialized variable"); else return table[variable]; } void SymbolTable::init() { table.clear(); // Clears the map, removes all elements. }

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• Unit testing class in a web service in .net

  - by Dan Bailiff

  After some digging here, I took the advice in this thread: http://stackoverflow.com/questions/371961/how-to-unit-test-c-web-service-with-visual-studio-2008 I've created a separate class and my web service class is just a wrapper for that one. The problem is that when I try to create a unit test project in VS2008, it insists on creating a unit test that acts like I'm testing the web service calls instead of the class I specified. I can't get to the class I'm trying to test. I have a web service "subscription_api.asmx". The code behind is "subscription_api.cs" which contains the web method wrapper calls to the real code at "subscription.cs". I would expect to be able to do the following: [TestMethod()] public void GetSystemStatusTest() { subscription sub = new subscription(); XmlNode node = sub.GetSystemStatusTest(); Assert.IsNotNull(node); } But instead I get this mess which is autogenerated from VS'08: /// <summary> ///A test for GetSystemStatus ///</summary> // TODO: Ensure that the UrlToTest attribute specifies a URL to an ASP.NET page (for example, // http://.../Default.aspx). This is necessary for the unit test to be executed on the web server, // whether you are testing a page, web service, or a WCF service. [TestMethod()] [HostType("ASP.NET")] [AspNetDevelopmentServerHost("C:\\CVSROOT\\rnr\\pro\\product\\wms\\ss\\subscription_api", "/subscription_api")] [UrlToTest("http://localhost/subscription_api")] public void GetSystemStatusTest() { subscription_Accessor target = new subscription_Accessor(); // TODO: Initialize to an appropriate value XmlNode expected = null; // TODO: Initialize to an appropriate value XmlNode actual; actual = target.GetSystemStatus(); Assert.AreEqual(expected, actual); Assert.Inconclusive("Verify the correctness of this test method."); } Additionally, there is a "subscription_api.accessor" in the Test References folder. When I try this: [TestMethod()] public void GetSystemStatusTest2() { subscription_Accessor sub = new subscription_Accessor(); XmlNode node = sub.GetSystemStatus(); Assert.IsNotNull(node); } I get an error: Test method subscription_api.Test.subscriptionTest.GetSystemStatusTest2 threw exception: System.TypeInitializationException: The type initializer for 'subscription_Accessor' threw an exception. ---> System.ArgumentNullException: Value cannot be null. I'm really new to unit testing and feel lost. How can I create a unit test just for my subscription class in "subscription.cs" without testing the web service? Am I limited to testing within the same project (I hope not)? Do I have to put the target class in its own project outside of the web service project?

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• help me to choose the best soulotion for my purpose to build my software.

  - by rima

  before answer me plz thinking about the futures of these kind of program and answer me plz. I wanna get some data from oracle server like: 1-get all the function,package,procedure and etc for showing them or drop them & etc... 2-compile my *.sql files,get the result if they have problem & etc... becuz I was beginner in oracle first of all I for solve the second problem I try to connect to sqlPlus by RUN sqlplus and trace the output(I mean,I change the output stream of shell and trace what happend and handle the assigned message to customer. NOW THIS PART SUCCEED. just a little bit I have problem with get all result because the output is asynchronous.any way... [in this case I log in to oracle Server by send argument to the sqlplus by make a process in c#] after that I try to get all function,package or procedure name,but I have problem in speed!so I try to use oracle.DataAccess.dll to connect the database. now I m so confusing about: which way is correct way to build a program that work like Oracle Developer! I do not have any experience for like these program how work. If Your answer is I must use the second way follow this part plz: I search a little bit the Golden,PLedit (Benthic software),I have little bit problem how I must create the connection string?because I thinking about how I can find the host name or port number that oracle work on them?? am I need read the TNSNames.Ora file? IF your answer is I must use the first way follow this part plz: do u have any Idea for how I parse the output?because for example the result of a table is so confusing...[i can handle & program it but I really need someone experience,because the important things to me learn how such software work so nice and with quick response?] All of the has different style in output... If you are not sure Can u help me which book can help me in this way i become expert? becuz for example all the C# write just about how u can connect to DB and the DB books write how u can use this DB program,I looking for a book that give me some Idea how develop an interface for do transaction between these two.not simple send and receive data,for example how write a compiler for them. the language of book is not different for me i know C#,java,VB,sql,Oracle Thanks.

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• My UITabBarController isn't appearing, but its first view is?

  - by E-Madd

  I've done some reorganizing of my project recently and now I'm not seeing my tab bar controller, but its first view controller's view is appearing. Here's a breakdown of everything that happens prior to the problem. App Delegate loads FirstViewController with nib. FirstViewController loads the application data from my server and then presents MainViewController with a modal transition. MainViewController is where the UITabBarController is supposed to be appearing. It's a very simple class. The .h @interface MainViewController : UIViewController <UITabBarControllerDelegate> { IBOutlet UITabBarController *tabBarController; } @property (nonatomic, retain) UITabBarController *tabBarController; @end The .m @implementation MainViewController @synthesize tabBarController; - (void)viewDidLoad { NSLog(@"MainViewController viewDidLoad"); //set tab bar controller delegate to self tabBarController.delegate = self; // home view HomeViewController *home = [[HomeViewController alloc] initWithTab]; // menu view MenuViewController *menu = [[MenuViewController alloc] initWithTab]; // special offers view SpecialOffersViewController *so = [[SpecialOffersViewController alloc] initWithTab]; // events view EventsViewController *events = [[EventsViewController alloc] initWithTab]; // info view InfoViewController *info = [[InfoViewController alloc] initWithTab]; //populate the tab bar controller with view controllers NSArray *controllers = [NSArray arrayWithObjects:home, menu, so, events, info, nil]; tabBarController.viewControllers = controllers; //release view controllers [home release]; [menu release]; [so release]; [events release]; [info release]; [controllers release]; //add tab bar controller to view [self.view addSubview:tabBarController.view]; [super viewDidLoad]; } and here's the bit from FirstViewController that modally presents the MainViewController... MainViewController *controller = [[MainViewController alloc] initWithNibName:@"MainViewController" bundle:nil]; controller.modalTransitionStyle = UIModalTransitionStyleFlipHorizontal; [self presentModalViewController:controller animated:YES]; [controller release]; I'm not getting any compiler errors or warnings and the app runs swell... no crashing. It just isn't showing the darned TabBar, and it used to when I was creating it on my AppDelegate. I checked everything in my NIB and my outlets seem to be hooked up ok. I have no idea what's happened. Help!

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• Coping with feelings of technical mediocrity

  - by Karim

  As I've progressed as a programmer, I noticed more nuance and areas I could study in depth. In part, I've come to think of myself from, at one point, a "guru" to now much less, even mediocre or inadequate. Is this normal, or is it a sign of a destructive excessive ambition? Background I started to program when I was still a kid, I had about 10 or 11 years. I really enjoy my work and never get bored from it. It's amazing how somebody could be paid for what he really likes to do and would be doing it anyway even for free. When I first started to program, I was feeling proud of what I was doing, each application I built was for me a success and after 2-3 year I had a feeling that I'm a coding guru. It was a nice feeling. ;-) But the more I was in the field and the more types of software I started to develop, I was starting to have a feeling that I'm completely wrong in thinking I'm a guru. I felt that I'm not even a mediocre developer. Each new field I start to work on is giving me this feeling. Like when I once developed a device driver for a client, I saw how much I need to learn about device drivers. When I developed a video filter for an application, I saw how much do I still need to learn about DirectShow, Color Spaces, and all the theory behind that. The worst thing was when I started to learn algorithms. It was several years ago. I knew then the basic structures and algorithms like the sorting, some types of trees, some hashtables, strings, etc. and when I really wanted to learn a group of structures I learned about 5-6 new types and saw that in fact even this small group has several hundred subtypes of structures. It's depressing how little time people have in their lives to learn all this stuff. I'm now a software developer with about 10 years of experience and I still feel that I'm not a proficient developer when I think about things that others do in the industry.

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• Perfect Forwarding to async lambda

  - by Alexander Kondratskiy

  I have a function template, where I want to do perfect forwarding into a lambda that I run on another thread. Here is a minimal test case which you can directly compile: #include <thread> #include <future> #include <utility> #include <iostream> #include <vector> /** * Function template that does perfect forwarding to a lambda inside an * async call (or at least tries to). I want both instantiations of the * function to work (one for lvalue references T&, and rvalue reference T&&). * However, I cannot get the code to compile when calling it with an lvalue. * See main() below. */ template <typename T> std::string accessValueAsync(T&& obj) { std::future<std::string> fut = std::async(std::launch::async, [](T&& vec) mutable { return vec[0]; }, std::forward<T>(obj)); return fut.get(); } int main(int argc, char const *argv[]) { std::vector<std::string> lvalue{"Testing"}; // calling with what I assume is an lvalue reference does NOT compile std::cout << accessValueAsync(lvalue) << std::endl; // calling with rvalue reference compiles std::cout << accessValueAsync(std::move(lvalue)) << std::endl; // I want both to compile. return 0; } For the non-compiling case, here is the last line of the error message which is intelligible: main.cpp|13 col 29| note: no known conversion for argument 1 from ‘std::vector<std::basic_string<char> >’ to ‘std::vector<std::basic_string<char> >&’ I have a feeling it may have something to do with how T&& is deduced, but I can't pinpoint the exact point of failure and fix it. Any suggestions? Thank you! EDIT: I am using gcc 4.7.0 just in case this could be a compiler issue (probably not)

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