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• How do I create a simple Windows form to access a SQL Server database?

  - by NoCatharsis

  I believe this is a very novice question, and if I'm using the wrong forum to ask, please advise. I have a basic understanding of databasing with MS SQL Server, and programming with C++ and C#. I'm trying to teach myself more by setting up my own database with MS SQL Server Express 2008 R2 and accessing it via Windows forms created in C# Express 2010. At this point, I just want to keep it to free or Express dev tools (not necessarily Microsoft though). Anyway, I created a database using the instructions provided here and I set the data types appropriately for each column (no errors in setup at least). Now I'm designing the GUI in C# Express but I've kind of hit a wall as far as the database connection. Is there a simple way to access the database I created locally using C# Express? Can anyone suggest a guide that has all this spelled out already? I am a self-learner so I look forward to teaching myself how to use these applications, but any pointers to start me off in the right direction would be greatly appreciated.

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• Where do objects merge/join data in a 3-tier model?

  - by BerggreenDK

  Its probarbly a simple 3-tier problem. I just want to make sure we use the best practice for this and I am not that familiary with the structures yet. We have the 3 tiers: GUI: ASP.NET for Presentation-layer (first platform) BAL: Business-layer will be handling the logic on a webserver in C#, so we both can use it for webforms/MVC + webservices DAL: LINQ to SQL in the Data-layer, returning BusinessObjects not LINQ. DB: The SQL will be Microsoft SQL-server/Express (havent decided yet). Lets think of setup where we have a database of [Persons]. They can all have multiple [Address]es and we have a complete list of all [PostalCode] and corresponding citynames etc. The deal is that we have joined a lot of details from other tables. {Relations}/[tables] [Person]:1 --- N:{PersonAddress}:M --- 1:[Address] [Address]:N --- 1:[PostalCode] Now we want to build the DAL for Person. How should the PersonBO look and when does the joins occure? Is it a business-layer problem to fetch all citynames and possible addressses pr. Person? or should the DAL complete all this before returning the PersonBO to the BAL ? Class PersonBO { public int ID {get;set;} public string Name {get;set;} public List<AddressBO> {get;set;} // Question #1 } // Q1: do we retrieve the objects before returning the PersonBO and should it be an Array instead? or is this totally wrong for n-tier/3-tier?? Class AddressBO { public int ID {get;set;} public string StreetName {get;set;} public int PostalCode {get;set;} // Question #2 } // Q2: do we make the lookup or just leave the PostalCode for later lookup? Can anyone explain in what order to pull which objects? Constructive criticism is very welcome. :o)

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• Mercurial CLI is slow in C#?

  - by pATCheS

  I'm writing a utility in C# that will make managing multiple Mercurial repositories easier for the way my team is using it. However, it seems that there is always about a 300 to 400 millisecond delay before I get anything back from hg.exe. I'm using the code below to run hg.exe and hgtk.exe (TortoiseHg's GUI). The code currently includes a Stopwatch and some variables for timing purposes. The delay is roughly the same on multiple runs within the same session. I have also tried specifying the exact path of hg.exe, and got the same result. static string RunCommand(string executable, string path, string arguments) { var psi = new ProcessStartInfo() { FileName = executable, Arguments = arguments, WorkingDirectory = path, UseShellExecute = false, RedirectStandardError = true, RedirectStandardInput = true, RedirectStandardOutput = true, WindowStyle = ProcessWindowStyle.Maximized, CreateNoWindow = true }; var sbOut = new StringBuilder(); var sbErr = new StringBuilder(); var sw = new Stopwatch(); sw.Start(); var process = Process.Start(psi); TimeSpan firstRead = TimeSpan.Zero; process.OutputDataReceived += (s, e) => { if (firstRead == TimeSpan.Zero) { firstRead = sw.Elapsed; } sbOut.Append(e.Data); }; process.ErrorDataReceived += (s, e) => sbErr.Append(e.Data); process.BeginOutputReadLine(); process.BeginErrorReadLine(); var eventsStarted = sw.Elapsed; process.WaitForExit(); var processExited = sw.Elapsed; sw.Reset(); if (process.ExitCode != 0 || sbErr.Length > 0) { Error.Mercurial(process.ExitCode, sbOut.ToString(), sbErr.ToString()); } return sbOut.ToString(); } Any ideas on how I can speed things up? As it is, I'm going to have to do a lot of caching in addition to threading to keep the UI snappy.

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• My QFileSystemModel doesn't work as expected in PyQt

  - by Skilldrick

  I'm learning the Qt Model/View architecture at the moment, and I've found something that doesn't work as I'd expect it to. I've got the following code (adapted from Qt Model Classes): from PyQt4 import QtCore, QtGui model = QtGui.QFileSystemModel() parentIndex = model.index(QtCore.QDir.currentPath()) print model.isDir(parentIndex) #prints True print model.data(parentIndex).toString() #prints name of current directory childIndex = model.index(0, 0, parentIndex) print model.data(childIndex).toString() rows = model.rowCount(parentIndex) print rows #prints 0 (even though the current directory has directory and file children) The question: Is this a problem with PyQt, have I just done something wrong, or am I completely misunderstanding QFileSystemModel? According to the documentation, model.rowCount(parentIndex) should return the number of children in the current directory. The QFileSystemModel docs say that it needs an instance of a Gui application, so I've also placed the above code in a QWidget as follows, but with the same result: import sys from PyQt4 import QtCore, QtGui class Widget(QtGui.QWidget): def __init__(self, parent=None): QtGui.QWidget.__init__(self, parent) model = QtGui.QFileSystemModel() parentIndex = model.index(QtCore.QDir.currentPath()) print model.isDir(parentIndex) print model.data(parentIndex).toString() childIndex = model.index(0, 0, parentIndex) print model.data(childIndex).toString() rows = model.rowCount(parentIndex) print rows def main(): app = QtGui.QApplication(sys.argv) widget = Widget() widget.show() sys.exit(app.exec_()) if __name__ == '__main__': main()

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• How exactly do MbUnit's [Parallelizable] and DegreeOfParallelism work?

  - by BenA

  I thought I understood how MbUnit's parallel test execution worked, but the behaviour I'm seeing differs sufficiently much from my expectation that I suspect I'm missing something! I have a set of UI tests that I wish to run concurrently. All of the tests are in the same assembly, split across three different namespaces. All of the tests are completely independent of one another, so I'd like all of them to be eligible for parallel execution. To that end, I put the following in the AssemblyInfo.cs: [assembly: DegreeOfParallelism(8)] [assembly: Parallelizable(TestScope.All)] My understanding was that this combination of assembly attributes should cause all of the tests to be considered [Parallelizable], and that the test runner should use 8 threads during execution. My individual tests are marked with the [Test] attribute, and nothing else. None of them are data-driven. However, what I actually see is at most 5-6 threads being used, meaning that my test runs are taking longer than they should be. Am I missing something? Do I need to do anything else to ensure that all of my 8 threads are being used by the runner? N.B. The behaviour is the same irrespective of which runner I use. The GUI, command line and TD.Net runners all behave the same as described above, again leading me to think I've missed something. EDIT: As pointed out in the comments, I'm running v3.1 of MbUnit (update 2 build 397). The documentation suggests that the assembly level [parallelizable] attribute is available, but it does also seem to reference v3.2 of the framework despite that not yet being available. EDIT 2: To further clarify, the structure of my assembly is as follows: assembly - namespace - fixture - tests (each carrying only the [Test] attribute) - fixture - tests (each carrying only the [Test] attribute) - namespace - fixture - tests (each carrying only the [Test] attribute) - fixture - tests (each carrying only the [Test] attribute) - namespace - fixture - tests (each carrying only the [Test] attribute) - fixture - tests (each carrying only the [Test] attribute)

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• Why is BorderLayout calling setSize() and setBounds()?

  - by ags

  I'm trying to get my head around proper use of the different LayoutManagers to make my GUI design skills more efficient and effective. For me, that usually requires a detailed understanding of what is going on under the hood. I've found some good discussion of the interaction and consequences of a Container using BorderLayout containing a Container using FlowLayout. I understand it for the most part, but wanted to confirm my mental model and to do so I am looking at the code for BorderLayout. In the code snippet below taken from BorderLayout.layoutContainer(), note the calls to the child Component's setSize() method followed by setBounds(). Looking at the source for these methods of Component, setSize() actually calls setBounds() with the current values for Component.x and Component.y. Why is this done (and not entirely redudant?) Doesn't the setBounds() call completely overwrite the results of the setSize() call? if ((c=getChild(NORTH,ltr)) != null) { c.setSize(right - left, c.height); Dimension d = c.getPreferredSize(); c.setBounds(left, top, right - left, d.height); top += d.height + vgap; } I'm also tring to understand where/when the child Component's size is initially set (before the LayoutManager.layoutContainer() method is called). Finally, this post itself raises a "meta-question": in a situation like this, where the source is available elsewhere, is the accepteed protocol to include the entire method? Or some other way to make it easier for folks to participate in the thread? Thanks.

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• Why is my panel not positioned correctly even after setting the boundaries?

  - by nutellafella

  I'm trying to make a simple GUI with radio buttons and I grouped them into one panel. I wanted it positioned on the leftmost side so I used the setBounds method. Whatever numbers I put on the parameters, the panel won't move. Are panels not affected by the setBounds method? Or is there another way to position my panel. Here's the snippet of my code: JPanel radioPanel = new JPanel(); radioPanel.setLayout(new GridLayout(3,1)); JRadioButton Rbutton1 = new JRadioButton("Credit Card"); JRadioButton Rbutton2 = new JRadioButton("E-Funds"); JRadioButton Rbutton3 = new JRadioButton("Check"); Rbutton3.setSelected(true); ButtonGroup Bgroup = new ButtonGroup(); Bgroup.add(Rbutton1); Bgroup.add(Rbutton2); Bgroup.add(Rbutton3); radioPanel.add(Rbutton1); radioPanel.add(Rbutton2); radioPanel.add(Rbutton3); radioPanel.setBounds(10,50,50,40); //this is where I'm trying to position the panel with the radio buttons paymentPanel.add(radioPanel); contentPane.add(paymentPanel); //contentPane is the frame contentPane.setVisible(true);

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• Java: Help constructing a fillTextFields() method

  - by Holly

  I have a Java project where I am to connect to a database and create buttons (next, new, save, delete, previous) to navigate through the database content where there are appropriate text fields and labels for the specific information. I'll use the code below as an example (each button is set up very similar)... I have it as follows: JButton jbtnNext = new JButton("Next ->"); jbtnNext.addActionListener(this); if (e.getSource() == jbtnNext) jbtnNext_Click(); private void jbtnNext_Click() { JOptionPane.showMessageDialog(null, "Next" ,"Button Pressed", JOptionPane.INFORMATION_MESSAGE); try { if (rset.next()) { fillTextFields(true); }else{ //Display result in a dialog box JOptionPane.showMessageDialog(null, "Not found"); } } catch (SQLException ex) { ex.printStackTrace(); } } The professor gave the following outline of logic to construct the fillTextFields() method: Construct the method to provide reusable code that would fill the JTextFields on the GUI with appropriate values from current record from the database (when "Previous or "Next" buttons are pressed) or blank values (when the new Button is pressed). To determine when the current record was to provide values (next and previous) or the value would be blank (new button) pass a boolean argument into the method. If data from the current record was to be used as fill values, pass true for both previous and next button code after moving the record pointer. If the new button was pressed and want to fill with blank values, pass false to the method. Inside the method, use a conditional expression to evaluate the boolean variable. If true, The appropriate get----() resultset method is used to fill the JTextFields. If false, fill them with "". The .setText() method of the JTextField is used to fill each JTextField. Make sure the fillTextFields method throws the appropriate exception. I understand and have the previous and next button methods passing true, while the new button method is passing false, but I don't quite understand how to set up the fillTextFields() method correctly or how to "throw the appropriate exception"... Any help would really be appreciated, thank you!

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• Can't diagnose my MySQL root user problem

  - by George Crawford

  Hi all, I have a problem with the MySQL root user in My MySQL setup, and I just can't for the life of me work out how to fix it. It seems that I have somehow messed up the root user, and my access to databases is now very erratic. For reference, I'm using MAMP on OS X to provide the MySQL server. I'm not sure how much that matters though - I'd guess that whatever I've done will require a command-line fix to solve it. I can start MySQL using MAMP as usual, and access databases using the 'standard' users I have created for my PHP apps. However, the root user, which I use in my MySQL GUI client, and also in phpMyAdmin, can only access the "information_schema" database, as well as two I have created manually, and presumably (and mistakenly) left permissions wide open for. My 15 or so other databases cannot be accessed my the root user. When I load up phpMyAdmin, the home screen says: "Create new database: No Privileges". I certainly did at some stage change my root user's password using the MAMP dialog. But I don't remember if I did anything else which might have caused this problem. I've tried changing the password again, and there seems to be no change in the issue. I've also tried resetting root password using the command line, including starting mysql manually with --skip-grant-tables then flushing privs, but again, nothing seems to fix the issue. I've come to the end of my ideas, and would very much appreciate some step-by-step advice and diagnosis from one of the experts here! Many thanks for your help.

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• Excel 2007 UDF keeps failing, why?

  - by Zan

  I've been trying to browse info about this for a while now. The user defined functions in Excel 2007 just make no sense to me whatsoever. According to all the tutorials, it should be really simple. Just press alt + f11, insert a new module, and enter the VBA code there. At this point typing '=FUNCTIONNAME(parameters)' into any cell should make it work. It did, at first. Then upon closing and reopening the worksheet it stopped working. I checked to see that macros were enabled, but either way, that didn't help. Then I browsed the graphic UI from the function button to locate user defined functions. I found it there by name of 'MyExcelWorksheet.xls!FUNCTIONNAME.FUNCTIONNAME' and clicking that, it started working again. Now, a day later, I get back to working on this and it's broken, again. I just get #NAME? error or some "Function Arguments - Function doesn't use any arguments" -popup (translated from Finnish Excel, not sure what that msg is in English) when I select the function from the GUI. So what does it take to just create a function, and actually make it work and KEEP working? For the life of me I can't figure out why this has to be so difficult. :) I'm starting to think my company has some weird settings enabled or whatever, because judging by the lack of information I've found on the subject, this isn't supposed to happen.

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• How do I code and compile an Amiga application?

  - by nbolton

  I would like to program an application for the Amiga, just for fun! Please could someone post a step by step howto based on the following? Exactly what programming tools I should use, are there any already installed? Am I limited to plain text editors, or are there IDEs and debugging tools available? If no tools are already installed, how can this done? Are there free ones? I'd like to learn a traditional Amiga language, could you reccomend one? What should I use to compile the language you suggest? Please could you suggest tools I may use to debug the suggested language? Are there any libraries I should be aware of, such as GUI libraries? Some things to note... I'm running Workbench 3.1 from within the WinUAE emulator. From Workbench, I can access files from my Windows hard drive. I'd like to code and compile it from Workbench if possible. I'm running WinUAE in A1200 mode, not sure if that matters. There's an application already installed called MEmacs. I know C++ and C# very well, maybe there's a similar Amiga language. I'm aware that you can code with C and C++, but I want to learn a new language. Update: I have answered my own question, but please do contribute more answers as I intend on extending my answer. Thanks to all that have contributed so far, you've been very helpful!

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• Decompiling an old Program

  - by Pedro Laranjeiro

  Hi. I have been asked to update a program written in 1987 in Delphi (I guess). I have no documentation about this program only a few side notes the programmer took that don't make too much sense to make. The cd show this files: Size | Filename - 19956 VP.DTA - 142300 VP.LEX - 404 VP.NDX - 126502 VP.RCS - 131016 VP.SCR - 150067 VP.XEL - 101791 vp.exe Is anyone of this files a database? If so can I access it's data? I tried several code decompilers but they show a message saying it was not a Win32 compatible application. The program run in MS-DOS. Is it possible to obtain the source code? Can I use this code in any way to build a new application? Thanks Update01: I can run the program in MSDOS. The program conjugate verbs and shows an example sentence where the verb can be used. The GUI is a little bit confusing and there is no help menu so I can't see all the capabilities of the program.

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• Which compiler option I should choose?

  - by Surjya Narayana Padhi

  Hi Geeks, I have to use the third party static library for my qt application to run on windows. The third party provides me a .lib and .h file for use. These libraries are compiled with MSVC compiler. My qt Creator is using MinGW compiler to compile my application. I copied the .h and .lib file to my qt project directory and then added those in .pro file as follows QT += core gui TARGET = MyTest TEMPLATE = app LIBS += C:\Qt\2010.05\qt\MyTest\newApi.lib SOURCES += main.cpp\ mainwindow.cpp HEADERS += mainwindow.h \ newApi.h FORMS += mainwindow.ui Now I am getting some runtime error like this - Starting C:\Qt\2010.05\qt\MyTest-build-desktop\debug\MyTest.exe... C:\Qt\2010.05\qt\MyTest-build-desktop\debug\MyTest.exe exited with code -1073741515 Can any body suggest is this runtime error is due to mismatch of compiler? (because of my .lib file I added is comipled in MSVC compiler and my qt app is compiled using MinGW compiler) If not what may be the reason? Am I missing anything in adding the .h and .lib file to my qt project? If my MinGW compiler will not support the .lib file generated in MSVC compiler what may be the work-arround? Can I create the .lib files in MinGW compiler? or this format is supported only by MSVC compiler only? Please suggest...

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• Qt/C++ - confused about caller/callee, object ownership

  - by Isabel

  I am creating a GUI to manipulate a robot arm. The location of the arm can be described by 6 floats (describing the positions of the various arm joints. The interface consists of a QGraphicsView with a diagram of the arm (which can be clicked to change the arm position - adjusting the 6 floats). The interface also has 6 lineEdit boxes, to also adjust those values separately. When the graphics view is clicked, and when the line edit boxes are changed, I'd like the line edit boxes / graphics view to stay in synchronisation. This brings me to confusion about how to store the 6 floats, and trigger events when they're updated. My current idea is this: The robot arm's location should be represented by a class, RobotArmLocation. Objects of this class then have methods such as obj.ShoulderRotation() and obj.SetShoulderRotation(). The MainWindow has a single instance of RobotArmLocation. Next is the bit I'm more confused about, how to join everything up. I am thinking: The MainWindow has a ArmLocationChanged slot. This is signalled whenever the location object is changed. The diagram class will have a SetRobotArmLocation(RobotArmLocation &loc). When the diagram is changed, it's free to change the location object, and fire a signal to the ArmLocationChanged slot. Likewise, changing any of the text boxes will fire a signal to that ArmLocationChanged slot. The slot then has code to synchronise all the elements. This kind of seems like a mess to me, does anyone have any other suggestions? I've also thought of the following, does it have any merrit? The RobotArmLocation class has a ValueChanged slot, the diagram and textboxes can use that directly, and bypass the MainWindow directly (seems cleaner?) thanks for any wisdom!

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• Are Java developers really paid more than .Net developers? Also, should I just try and work with C?(

  - by Jon

  Ok, so I graduated about a year and a half ago. In college days I used to be really good (and keen) on C/C++. I've even done some multithreading and socket programming in C. Created networked GUI apps for linux using GTK etc.Now,I've been working since I graduated and well, let's say, I've been stereotyped with .net. That's all I have experience with in these years (Vb.net,asp.net,javascript). I'm pretty comfortable with all of the above and also SQL server.a)Cutting to the chase, I've begun to notice how .net jobs don't seem to pay all that well as Java. Jobs seeking similar number of yrs of experience offer almost twice for java developers. Does it mean I should consider switching?b)My heart still goes out for C. As a surrogate I've tried working with VC++ 6.0 (I know they aren't the same!). I've tried my hand with DDK,SDK,COM etc. Should I try finding jobs there or am I too inexperienced. Somehow, I can't find any openings for C. Where are they? Sometimes I get frustrated and feel that maybe I should just go for MS or something. Possibly that'll help me in landing with 'fatter paying jobs' in the field that I wish to work.

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• Python 4 steps setup with progressBars

  - by Samuel Taylor

  I'm having a problem with the code below. When I run it the progress bar will pulse for around 10 secs as meant to and then move on to downloading and will show the progress but when finished it will not move on to the next step it just locks up. import sys import time import pygtk import gtk import gobject import threading import urllib import urlparse class WorkerThread(threading.Thread): def __init__ (self, function, parent, arg = None): threading.Thread.__init__(self) self.function = function self.parent = parent self.arg = arg self.parent.still_working = True def run(self): # when does "run" get executed? self.parent.still_working = True if self.arg == None: self.function() else: self.function(self.arg) self.parent.still_working = False def stop(self): self = None class MainWindow: def __init__(self): gtk.gdk.threads_init() self.wTree = gtk.Builder() self.wTree.add_from_file("gui.glade") self.mainWindows() def mainWindows(self): self.mainWindow = self.wTree.get_object("frmMain") dic = { "on_btnNext_clicked" : self.mainWindowNext, } self.wTree.connect_signals(dic) self.mainWindow.show() self.installerStep = 0 # 0 = none, 1 = preinstall, 2 = download, 3 = install info, 4 = install #gtk.main() self.mainWindowNext() def pulse(self): self.wTree.get_object("progress").pulse() if self.still_working == False: self.mainWindowNext() return self.still_working def preinstallStep(self): self.wTree.get_object("progress").set_fraction(0) self.wTree.get_object("btnNext").set_sensitive(0) self.wTree.get_object("notebook1").set_current_page(0) self.installerStep = 1 WT = WorkerThread(self.heavyWork, self) #Would do a heavy function here like setup some thing WT.start() gobject.timeout_add(75, self.pulse) def downloadStep(self): self.wTree.get_object("progress").set_fraction(0) self.wTree.get_object("btnNext").set_sensitive(0) self.wTree.get_object("notebook1").set_current_page(0) self.installerStep = 2 urllib.urlretrieve('http://mozilla.mirrors.evolva.ro//firefox/releases/3.6.3/win32/en-US/Firefox%20Setup%203.6.3.exe', '/tmp/firefox.exe', self.updateHook) self.mainWindowNext() def updateHook(self, blocks, blockSize, totalSize): percentage = float ( blocks * blockSize ) / totalSize if percentage > 1: percentage = 1 self.wTree.get_object("progress").set_fraction(percentage) while gtk.events_pending(): gtk.main_iteration() def installInfoStep(self): self.wTree.get_object("btnNext").set_sensitive(1) self.wTree.get_object("notebook1").set_current_page(1) self.installerStep = 3 def installStep(self): self.wTree.get_object("progress").set_fraction(0) self.wTree.get_object("btnNext").set_sensitive(0) self.wTree.get_object("notebook1").set_current_page(0) self.installerStep = 4 WT = WorkerThread(self.heavyWork, self) #Would do a heavy function here like setup some thing WT.start() gobject.timeout_add(75, self.pulse) def mainWindowNext(self, widget = None): if self.installerStep == 0: self.preinstallStep() elif self.installerStep == 1: self.downloadStep() elif self.installerStep == 2: self.installInfoStep() elif self.installerStep == 3: self.installStep() elif self.installerStep == 4: sys.exit(0) def heavyWork(self): time.sleep(10) if __name__ == '__main__': MainWindow() gtk.main() I have a feeling that its something to do with: while gtk.events_pending(): gtk.main_iteration() Is there a better way of doing this?

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• Unmanaged Process in Mono

  - by Residuum

  I want to start a quite expensive process (jackd) from a Mono application, and do not need full access to the process from the application itself. As the process is so expensive in terms of CPU usage, a Glib.IdleHandler for polling the process will not work, as it is never executed, and the GUI becomes unresponsive. Is there any way to have the cake and eating it at the same time in Mono? EDIT: I only need to be able to start and stop the process from Mono, I do not need information about the state of the process or if it has exited, as my application will register itself as a client to jackd, basically I need a "replacement" for bash's jackd &>/dev/null 2>&1 & for the System.Diagnostics.Process ;). Here is what I have so far for starting and stopping the process: public void StartJackd() { _jackd = new Process (); _jackd.StartInfo = _jackdStartup; if (_jackd.Start ()) { _jackd.EnableRaisingEvents = true; _jackd.Exited += JackdExited; } } public void StopJackd() { if (_jackd != null && !_jackd.HasExited) { _jackd.CloseMainWindow (); } } And somewhere else I have this code for registering the IdleHandler: GLib.Idle.Add(new GLib.IdleHandler(UpdateJackdConnections)); This handler will fire all the time, while the process is not running, but never, when jackd is running.

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• Are there any downsides in using C++ for network daemons?

  - by badcat

  Hey guys! I've been writing a number of network daemons in different languages over the past years, and now I'm about to start a new project which requires a new custom implementation of a properitary network protocol. The said protocol is pretty simple - some basic JSON formatted messages which are transmitted in some basic frame wrapping to have clients know that a message arrived completely and is ready to be parsed. The daemon will need to handle a number of connections (about 200 at the same time) and do some management of them and pass messages along, like in a chat room. In the past I've been using mostly C++ to write my daemons. Often with the Qt4 framework (the network parts, not the GUI parts!), because that's what I also used for the rest of the projects and it was simple to do and very portable. This usually worked just fine, and I didn't have much trouble. Being a Linux administrator for a good while now, I noticed that most of the network daemons in the wild are written in plain C (of course some are written in other languages, too, but I get the feeling that 80% of the daemons are written in plain C). Now I wonder why that is. Is this due to a pure historic UNIX background (like KISS) or for plain portability or reduction of bloat? What are the reasons to not use C++ or any "higher level" languages for things like daemons? Thanks in advance! Update 1: For me using C++ usually is more convenient because of the fact that I have objects which have getter and setter methods and such. Plain C's "context" objects can be a real pain at some point - especially when you are used to object oriented programming. Yes, I'm aware that C++ is a superset of C, and that C code is basically C++. But that's not the point. ;)

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• Sizing issues while adding a .Net UserControl to a TabPage

  - by TJ_Fischer

  I have a complex Windows Forms GUI program that has a lot of automated control generation and manipulation. One thing that I need to be able to do is add a custom UserControl to a newly instatiated TabPage. However, when my code does this I get automatic resizing events that cause the formatting to get ugly. Without detailing all of the different Containers that could possibly be involved, the basic issue is this: At a certain point in the code I create a new tab page: TabPage tempTabPage = new TabPage("A New Tab Page"); Then I set it to a certain size that I want it to maintain: tempTabPage.Width = 1008; tempTabPage.Height = 621; Then I add it to a TabControl: tabControl.TabPages.Add(tempTabPage); Then I create a user control that I want to appear in the newly added TabPage: CustomView customView = new CustomView("A new custom control"); Here is where the problem comes in. At this point both the tempTabPage and the customView are the same size with no padding or margin and they are the size I want them to be. I now try to add this new custom UserControl to the tab page like this: tempTabPage.Controls.Add(customView); When making this call the customView and it's children controls get resized to be larger and so parts of the customView are hidden. Can anyone give me any direction on what to look for or what could be causing this kind of issue? Thanks ahead of time.

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• Choosing design method for ladder-like word game.

  - by owca

  I'm trying to build a simple application, with the finished program looking like this : I will also have to implement two different GUI layouts for this. Now I'm trying to figure out the best method to perform this task. My professor told me to introduce Element class with 4 states : - empty - invisible (used in GridLayout) - first letter - other letter I've thought about following solutions (by List I mean any sort of Collection) : 1. Element is a single letter, and each line is Element[]. Game class will be array of arrays Element[]. I guess that's the dumbest way, and the validation might be troublesome. 2. Like previously but Line is a List of Element. Game is an array of Lines. 3. Like previously but Game is a List of Lines. Which one should I choose ? Or maybe do you have better ideas ? What collection would be best if to use one ?

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• Is ther a Designer for MFC in Visual Studio like for windows forms in .NET?

  - by claws

  Hello, I'm a .NET programmer. I've never developed anything in MFC. Currently I had to write a C++ application (console) for some image processing task. I finished writing it. But the point is I need to design GUI also for this. Well, there won't be anything complex. Just a window with few Buttons, RadioButtons, Check Boxes, PicturesBox & few sliders. thats it. I'm using VS 2008 and was expecting a .NET style form designer. Just to test, I created a MFC project (with all default configuration) and these files were created by default: ChildFrm.cpp MainFrm.cpp mfc.cpp mfcDoc.cpp mfcView.cpp stdafx.cpp Now, I'm unable to find a Designer. There is no View Designer. I've opened all the above *.cpp and in the code editor right clicked to see "Designer View". ToolBox is just empty because I'm in code editor mode. When I built the project. This is the window I get. How to open a designer?

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• How To perform a SQL Query to DataTable Operation That Can Be Cancelled

  - by David W

  I tried to make the title as specific as possible. Basically what I have running inside a backgroundworker thread now is some code that looks like: SqlConnection conn = new SqlConnection(connstring); SqlCommand cmd = new SqlCommand(query, conn); conn.Open(); SqlDataAdapter sda = new SqlDataAdapter(cmd); sda.Fill(Results); conn.Close(); sda.Dispose(); Where query is a string representing a large, time consuming query, and conn is the connection object. My problem now is I need a stop button. I've come to realize killing the backgroundworker would be worthless because I still want to keep what results are left over after the query is canceled. Plus it wouldn't be able to check the canceled state until after the query. What I've come up with so far: I've been trying to conceptualize how to handle this efficiently without taking too big of a performance hit. My idea was to use a SqlDataReader to read the data from the query piece at a time so that I had a "loop" to check a flag I could set from the GUI via a button. The problem is as far as I know I can't use the Load() method of a datatable and still be able to cancel the sqlcommand. If I'm wrong please let me know because that would make cancelling slightly easier. In light of what I discovered I came to the realization I may only be able to cancel the sqlcommand mid-query if I did something like the below (pseudo-code): while(reader.Read()) { //check flag status //if it is set to 'kill' fire off the kill thread //otherwise populate the datatable with what was read } However, it would seem to me this would be highly ineffective and possibly costly. Is this the only way to kill a sqlcommand in progress that absolutely needs to be in a datatable? Any help would be appreciated!

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• BackOffice Database Application FrontEnd - Program in C#/VB.Net or PHP?

  - by HK1

  I'm working on a project where there will be a MySQL database containing data that will mostly be displayed on the web using PHP. However, there is a need here for a back-office data entry application (linked to the same MySQL database) that is feature rich and easy to use. what I'm trying to understand is where we are at with web-based frontends. I find that there are still so many events and features that I can make use of in a Windows Desktop GUI written in something like C#, VB.Net or MS Access. I don't have a lot of experience programming UI for web but it's my impression that it's still more difficult and takes longer to get similar or the same functionality using non-MS web technologies (I dislike ASP.net, sorry) as compared to programming the desktop portion in a traditional desktop application language like C#, VB.Net, or MS Access. jQuery and jQuery UI are definately making things easier. Also, there's very rich online applications like Google Docs and Zoho but it's my impression that these are programmed by some of the top web UI programmers around, not to mention that it takes longer to write it and intensive testing to make it work in all of your target browsers. It also takes extra time and code to "block" browsers that don't meet the requirements. What programming language would you recommend? I know I may not have given enough information here but I'm not sure what I'm missing. If you have questions just leave a comment below so I can edit this post and answer the questions.

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• Could not load SWT library on Windows 32-bit

  - by Firzen

  I am almost done with one Java project that I have been developing on Linux. Now I need to build and test it on Windows. So I have installed Eclipse on Windows XP 32-bit, and imported my project. All dependencies of project are in jar files in lib folder, and on Linux everything works well, but on Windows XP I get following error: Exception in thread "main" java.lang.UnsatisfiedLinkError: Could not load SWT library. Reasons: no swt-pi-gtk-4234 in java.library.path no swt-pi-gtk in java.library.path Can't load library: C:\Documents and Settings\firzen\.swt\lib\win32\x86\swt-pi-gtk-4234.dll Can't load library: C:\Documents and Settings\firzen\.swt\lib\win32\x86\swt-pi-gtk.dll at org.eclipse.swt.internal.Library.loadLibrary(Library.java:331) at org.eclipse.swt.internal.Library.loadLibrary(Library.java:240) at org.eclipse.swt.internal.gtk.OS.<clinit>(OS.java:22) at org.eclipse.swt.internal.Converter.wcsToMbcs(Converter.java:63) at org.eclipse.swt.internal.Converter.wcsToMbcs(Converter.java:54) at org.eclipse.swt.widgets.Display.<clinit>(Display.java:133) at gui.Frontend.<init>(Frontend.java:51) at Fighter.main(Fighter.java:18) I have searched for these DLLs, but I have failed to find them. Where can I download these DLL files? Thanks in advance.

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• Multiple exports with MEF does some really heinous stuff -- why, and why is it allowed?

  - by Dave

  I have an interesting situation where I need to do something like this: [Export[typeof(ICandy1)] [Export[typeof(ICandy2)] public class Candy : ICandy2 { ... } where public interface ICandy1 { ... } public interface ICandy2 : ICandy1 { ... } I couldn't find any posts anywhere regarding using multiple [Export] attributes, so I figured, what the hell, might as well try it. At first glance, it actually seemed to work. I have a couple of methods that call into both interfaces of a Candy instance, and it was fine. However, as I started to test the app, I saw that the behavior wasn't right, and when looking at the Output window, I saw that I was getting tons of COMExceptions. I couldn't track down where they were all coming from, but they always occurred when a worker thread was sleeping. I figured that it had to be from the main thread, then, but didn't know how to debug this at all. Nothing should have been going on in the GUI, and I disabled my DispatchTimers just in case -- same thing. Even more strange than the COMExceptions was the really, really erratic behavior when stepping through code. About 30% of the time, when I single stepped, it would pop out of the method, or it would single step over two lines of code! Totally weird stuff that I am not used to seeing. The only thing that changed between working and non-working code was the introduction of MEF through my plugin loading code. So as a test, I changed my plugin assembly to only export one interface, and I hardcoded everything in the app that relied on the other (now not-implemented) interface. And now the COMExceptions are gone, and the weird debugging behavior is gone. Is this something people here have seen before? If MEF is not expected to allow a class to Export multiple interfaces, then shouldn't a CompositionException get raised when composing the parts? Can anyone explain why MEF would cause these weird problems???

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