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  • How to limit choice field options based on another choice field in django admin

    - by umnik700
    I have the following models: class Category(models.Model): name = models.CharField(max_length=40) class Item(models.Model): name = models.CharField(max_length=40) category = models.ForeignKey(Category) class Demo(models.Model): name = models.CharField(max_length=40) category = models.ForeignKey(Category) item = models.ForeignKey(Item) In the admin interface when creating a new Demo, after user picks category from the dropdown, I would like to limit the number of choices in the "items" drop-down. If user selects another category then the item choices should update accordingly. I would like to limit item choices right on the client, before it even hits the form validation on the server. This is for usability, because the list of items could be 1000+ being able to narrow it down by category would help to make it more manageable. Is there a "django-way" of doing it or is custom JavaScript the only option here?

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  • C# Initialize Subclass based on Parent object

    - by ctrlShiftBryan
    So basically I have this public class Ticket{ public TicketNumber {get; set;} ..a bunch more properties... } I want to add some properties using a subclass like this using subsumption instead of composition. public class TicketViewModel(Ticket ticket){ //set each property from value of Ticket passed in this.TicketNumber = ticket.TicketNumber; ...a bunch more lines of code.. //additional VM properties public SelectList TicketTypes {get; private set;} } How do I instantiate the properties without having to write all the lines like this this.TicketNumber = ticket.TicketNumber; Is there some kind of shortcut? Something like in the subclass constructor? this = ticket; Obviously this doesn't work but is their some way so I don't have to modify my subclass if addng/removing a property to the parent class? Or something?

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  • Invoke an Overloaded Constructor through this keyword (What's the Different between this two Sample code?)

    - by Alireza Dehqani
    using System; namespace ConsoleApplication1 { class Program { static void Main() { // Sample Sample ob = new Sample(); // line1 // Output for line1 /* * Sample(int i) * Sample() / // Sample2 Sample2 ob2 = new Sample2(); // line2 // Output for line2 / * Sample2() */ } } class Sample { // Fields private int a; // Constructors public Sample(int i) // Main Constructor { Console.WriteLine(" Sample(int i)"); a = i; } // Default Constructor public Sample() : this(0) { Console.WriteLine(" Sample()"); } } class Sample2 { // fields private int a; // Constructors public Sample2(int i) { Console.WriteLine("Sample2(int i)"); a = i; } public Sample2() { Console.WriteLine("Sample2()"); a = 0; } } }

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  • augment the factory pattern in java

    - by TP
    I am trying to use a factory pattern to create a QuestionTypeFactory where the instantiated classes will be like MultipleChoice, TrueFalseQuestion etc. The factory code looks something like this class QuestionFactory { public enum QuestionType { TrueFalse, MultipleChoice, Essay } public static Question createQuestion(QuestionType quesType) { switch (quesType) { case TrueFalse: return new TrueFalseQuestion(); case MultipleChoice: return new MultipleChoiceQuestion(); case Essay: return new EssayQuestion(); } throw new IllegalArgumentException("Not recognized."); } } This works ok for now. If I want to add another question type I will need to modify the factory class and I do not want to do that. How can I set it up so that each question class registers itself with the Factory so that when I add a new question type, I do not have to change the code for the factory? I am a bit new to java and am not sure how to do this.

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  • 'Error serializing body'. Problem calling Fedex webservice through .NET 3.5

    - by Simon_Weaver
    I'm using Fedex's web services and getting an annoying error right up front before I can actually get anywhere. There was an error in serializing body of message addressValidationRequest1: 'Unable to generate a temporary class (result=1). error CS0030: Cannot convert type 'FedEx.InterOp.AddressValidationServiceReference.ParsedElement[]' to 'FedEx.InterOp.AddressValidationServiceReference.ParsedElement' error CS0029: Cannot implicitly convert type 'FedEx.InterOp.AddressValidationServiceReference.ParsedElement' to 'FedEx.InterOp.AddressValidationServiceReference.ParsedElement[]' '. Please see InnerException for more details. I'm using .NET 3.5 and get a horrible named class generated for me (I'm not sure why it isn't just AddressValidationService): AddressValidationPortTypeClient addressValidationService = new ...; on this class I make my web service call: addressValidationService.addressValidation(request); This is when I get this error. The only references I can find to this error come from ancient 1.1 projects. In my case my DLL has references to System.Web and System.Web.Services which seemed to be an issue back then.

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  • How should I model the database for this problem? And which ORM can handle it?

    - by Kristof Claes
    I need to build some sort of a custom CMS for a client of ours. These are some of the functional requirements: Must be able to manage the list of Pages in the site Each Page can contain a number of ColumnGroups A ColumnGroup is nothing more than a list of Columns in a certain ColumnGroupLayout. For example: "one column taking up the entire width of the page", "two columns each taking up half of the width", ... Each Column can contain a number ContentBlocks Examples of a ContentBlock are: TextBlock, NewsBlock, PictureBlock, ... ContentBlocks can be given a certain sorting within a Column A ContentBlock can be put in different Columns so that content can be reused without having to be duplicated. My first quick draft of how this could look like in C# code (we're using ASP.NET 4.0 to develop the CMS) can be found at the bottom of my question. One of the technical requirements is that it must be as easy as possible to add new types of ContentBlocks to the CMS. So I would like model everything as flexible as possible. Unfortunately, I'm already stuck at trying to figure out how the database should look like. One of the problems I'm having has to do with sorting different types of ContentBlocks in a Column. I guess each type of ContentBlock (like TextBlock, NewsBlock, PictureBlock, ...) should have it's own table in the database because each has it's own different fields. A TextBlock might only have a field called Text whereas a NewsBlock might have fields for the Text, the Summary, the PublicationDate, ... Since one Column can have ContentBlocks located in different tables, I guess I'll have to create a many-to-many association for each type of ContentBlock. For example: ColumnTextBlocks, ColumnNewsBlocks and ColumnPictureBlocks. The problem I have with this setup is the sorting of the different ContentBlocks in a column. This could be something like this: TextBlock NewsBlock TextBlock TextBlock PictureBlock Where do I store the sorting number? If I store them in the associaton tables, I'll have to update a lot of tables when changing the sorting order of ContentBlocks in a Column. Is this a good approach to the problem? Basically, my question is: What is the best way to model this keeping in mind that it should be easy to add new types of ContentBlocks? My next question is: What ORM can deal with that kind of modeling? To be honest, we are ORM-virgins at work. I have been reading a bit about Linq-to-SQL and NHibernate, but we have no experience with them. Because of the IList in the Column class (see code below) I think we can rule out Linq-to-SQL, right? Can NHibernate handle the mapping of data from many different tables to one IList? Also keep in mind that this is just a very small portion of the domain. Other parts are Users belonging to a certain UserGroup having certain Permissions on Pages, ColumnGroups, Columns and ContentBlocks. The code (just a quick first draft): public class Page { public int PageID { get; set; } public string Title { get; set; } public string Description { get; set; } public string Keywords { get; set; } public IList<ColumnGroup> ColumnGroups { get; set; } } public class ColumnGroup { public enum ColumnGroupLayout { OneColumn, HalfHalf, NarrowWide, WideNarrow } public int ColumnGroupID { get; set; } public ColumnGroupLayout Layout { get; set; } public IList<Column> Columns { get; set; } } public class Column { public int ColumnID { get; set; } public IList<IContentBlock> ContentBlocks { get; set; } } public interface IContentBlock { string GetSummary(); } public class TextBlock : IContentBlock { public string GetSummary() { return "I am a piece of text."; } } public class NewsBlock : IContentBlock { public string GetSummary() { return "I am a news item."; } }

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  • __getattr__ on a module

    - by Matt Joiner
    How can implement the equivalent of a __getattr__ on a class, on a module? Example When calling a function that does not exist in a module's statically defined attributes, I wish to create an instance of a class in that module, and invoke the method on it with the same name as failed in the attribute lookup on the module. class A(object): def salutation(self, accusative): print "hello", accusative def __getattr__(mod, name): return getattr(A(), name) if __name__ == "__main__": salutation("world") Which gives: matt@stanley:~/Desktop$ python getattrmod.py Traceback (most recent call last): File "getattrmod.py", line 9, in <module> salutation("world") NameError: name 'salutation' is not defined Evidently something is not right about my assumed implementation.

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  • What is a custom collection?

    - by Win Coder
    A Group of objects. However i am having confusion in the following case. A sample class Class A { public string; } Class A_list { public A[] list; public A_list(A[] _list) { list = new A[_list.length]; for (int i = 0; i < _list.Length; i++) { list[i] = _list[i]; } } } static void Main(String[] args) { A[] names = new A[3] { new A("some"), new A("another"), new A("one"), }; A_list just_an_object = new A_list(names); } Which of the above is a custom collection the array or the object that holds array as a field or are both custom collections.

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  • How do I adjust overall width of rdlc report when some columns are hidden?

    - by user115487
    I have a customizable rdlc report where the user can choose which columns to show. All the columns are included in the report designer, and I use parameters to hide/show columns based on the user's choice. The report renders correctly, and only shows the selected columns, HOWEVER, the overall width of the report is the same as if all the columns were visible. This means that the report can have a huge empty area to the right of the selected columns, which looks very silly. So my question: Is there a way to adjust the report width dynamically at runtime to avoid a large silly empty area in the report? I attempted to do this in the designer by assigning a parameter to the width of the report body....but that was not allowed. The width cannot be an expression of any kind in the designer, only an actual value is allowed. Any suggestions?

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  • Sharing a connection string

    - by coure06
    hi, I am developing a class library (C#) that i will use it for my different projects (later). My class library dll will use the connection string /data context of the project which will reference my new dll. How can i do it? Lets say i have a class Library Project named "CLP", and a website project "WP". I can add reference to CLP.dll file but how i will pass a connection string/data context object to that dll? as CLP.dll will access db based on the connection string of the "WP". Not sure my problem is clear or not!

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  • How do I migrate a ManyToOne to a ManyToMany relationship in Hibernate?

    - by spderosso
    I have a instance field of a class X that is mapped using Hibernate as a Many to One relationship. E.g: public class X{ ... @ManyToOne(optional=false) private Y iField; ... } That is correctly working with a particular schema. I know want to change this instance field iField to a List and a Many to Many relationship. public class X{ ... @ManyToMany(optional=false) private List<Y> iField; ... } What steps should I follow? Do I have to change the schema? in which way? In case you need more info let me know. Thanks!

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  • How to enable Automatic Sorting of IEnumerable Data in GridView?

    - by ace
    How can I enable automatic sorting of my BLL which returns a List CustomerList:List in a GridView? Customer is my own strongly typed class and CustomerList is a List of customers. I know one approach is to set the AllowSorting property to true in the GridView and handle the OnSorting event and call a sorting method defined in my CustomerList class. However I would like a solution which is automatic in the sense that I do not have to handle the OnSorting Event, it should be like how GridView handles automatic sorting for DataView, DataTable, and DataSet. Is there an Interface I need to implement on my CustomerList or Customer class that will enable that functionality?

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  • Java Polymorphism - Selecting correct method based on subtype

    - by Marty Pitt
    Hi Given the following Class and Service layer signatures: public class PersonActionRequest { PersonVO person // ... other fields } public class MyServiceLayerClass { public void requestAction(PersonActionRequest request) { PersonVO abstractPerson = request.getPerson(); // call appropriate executeAction method based on subclass of PersonVO } private void executeAction(PersonVO person) {} private void executeAction(EmployeeVO employee) {} private void executeAction(ManagerVO manager) {} private void executeAction(UnicornWranglerVO unicornWrangler) {} } As discussed here, java will select the best method based on type info at compile time. (Ie., it will always select executeAction(PersonVO person) ). What's the most appropriate way to select the correct method? The internet tells me that using instanceof gets me slapped. However, I don't see the appropraite way to select the method without explictly casting abstractPerson to one of the other concrete types. Thanks Marty

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  • How do I convert CamelCase into human-readable names in Java?

    - by Frederik
    I'd like to write a method that converts CamelCase into a human-readable name. Here's the test case: public void testSplitCamelCase() { assertEquals("lowercase", splitCamelCase("lowercase")); assertEquals("Class", splitCamelCase("Class")); assertEquals("My Class", splitCamelCase("MyClass")); assertEquals("HTML", splitCamelCase("HTML")); assertEquals("PDF Loader", splitCamelCase("PDFLoader")); assertEquals("A String", splitCamelCase("AString")); assertEquals("Simple XML Parser", splitCamelCase("SimpleXMLParser")); assertEquals("GL 11 Version", splitCamelCase("GL11Version")); }

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  • Help with a Join in Rails 3

    - by Adam Albrecht
    I have the following models: class Event < ActiveRecord::Base has_many :action_items end class ActionItem < ActiveRecord::Base belongs_to :event belongs_to :action_item_type end class ActionItemType < ActiveRecord::Base has_many :action_items end And what I want to do is, for a given event, find all the action items that have an action item type with a name of "foo" (for example). So I think the SQL would go something like this: SELECT * FROM action_items a INNER JOIN action_item_types t ON a.action_item_type_id = t.id WHERE a.event_id = 1 AND t.name = "foo" Can anybody help me translate this into a nice active record query? (Rails 3 - Arel) Thanks!

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  • need to get the context value in top of page, where the context value will be set only at the bottom

    - by Mahadevan Alagar
    <script runat="server"> protected void Page_Load(object sender, EventArgs e) { Response.Write("Page Load:"); } public string setContext(string sName, string sVal) { HttpContext.Current.Items[sName] = sVal; return sVal; } public string getContext(string sName) { string sVal = "default"; if (HttpContext.Current.Items[sName] != null) sVal = HttpContext.Current.Items[sName].ToString(); else sVal = "empty"; return sVal; } </script> <html xmlns="http://www.w3.org/1999/xhtml"> <head> <title>Get Context in TOP ???</title> </head> <body> <div> <div id="divDest" name="divDest"> Top Content: Get1 :<%= getContext("topcontent") %> // returns "empty", BUT I Need "value to set" </div> <br /> Set1 : <%= setContext("topcontent", "value to set")%> <br /> // set the value <br /> Get2 : <%= getContext("topcontent") %><br /> // returns "value to set" <br /> <script language="javascript"> var elval = getElementVal("divTest"); document.getElementById("divDest").innerHTML = elval; //alert(elval); function getElementVal(elemid) { var elemval = document.getElementById(elemid); return elemval.innerHTML; } </script> </body> </html> I need to get the context value in top of page, where the context value will be set at the bottom of the page. Get context value == "empty", BUT need "something" Set context value to "something" Get context value == "something" I may use JS/AJAX, where the page source the value won't be present. BUT I need the TEXT in the View Source of the page too. Is there a way to wait for the context to set and then get, I have tried with User Control, prerender and render methods too. But I can't able to get it right. Any idea?

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  • Weird behavior of std::vector

    - by Nima
    I have a class like this: class OBJ{...}; class A { public: vector<OBJ> v; A(int SZ){v.clear(); v.reserve(SZ);} }; A *a = new A(123); OBJ something; a->v.push_back(something); This is a simplified version of my code. The problem is in debug mode it works perfect. But in release mode it crashes at "push_back" line. (with all optimization flags OFF) I debugged it in release mode and the problem is in the constructor of A. the size of the vector is something really big with dummy values and when I clear it, it doesn't change... Do you know why? Thanks,

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  • CSS Negative margins for positioning.

    - by Kyle Sevenoaks
    Is it ok to use negative margins for positioning? I have a lot in my current site and feel like it's not such a stable way to position things. I usually suggest to use them too. For example I have a checkout page with three divs on top of each other <div class="A"> header </div> <div class="B"> content </div> <div class="C"> footer </div> (A, B and C), which are meant to sit on top of each other, to appear attached. I did this using: .B { margin-top: -20px; } On div B, to meet the bottom of div A. Is this good practice or shall I re-code using top and left?

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  • Silverlight: Binding to static value

    - by queen3
    I need TextBlock.Text to be retrieved from translation manager, something like <TextBlock Text="{Binding TranslateManager.Translate('word')}" /> I don't want to set DataSource for all text blocks. The only way I found how to do this is to bind to "static" class and use converter: <TextBlock Text="{Binding Value, Source={StaticResource Translation}, Converter={StaticResource Translation}, ConverterParameter=NewProject}" /> And these helper class public class TranslationManager : IValueConverter { public static string Translate(string word) { return translate(word); } // this is dummy for fake static binding public string Value { get; set; } public object Convert(object value, Type targetType, object parameter, CultureInfo culture) { var name = parameter as string; return TranslationManager.Translate(name, name); } } But, is there a better - shorter - way?

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  • Java How to call method of grand parents?

    - by Arkaha
    Let's assume I have 3 classes A, B and C, each one extending the previous one. How do I call the code in A.myMethod() from C.myMethod() if B also implements myMethod? class A { public void myMethod() { // some stuff for A } } class B extends A { public void myMethod() { // some stuff for B //and than calling A stuff super.myMethod(); } } class C extends B { public void myMethod() { // some stuff for C // i don't need stuff from b, but i need call stuff from A // something like: super.super.myMethod(); ?? how to call A.myMethod(); ?? } }

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  • Write to static field - is FindBugs wrong in this case?

    - by htorque
    I have a Java class like this: public class Foo { public static int counter = 0; public void bar(int counter) { Foo.counter = counter; } } FindBugs warns me about writing to the static field counter via the instance method bar. However, if I change the code to: public class Foo { public static int counter = 0; public static void setCounter(int counter) { Foo.counter = counter; } public void bar(int counter) { setCounter(counter); } } Then FindBugs won't complain. Isn't that wrong? I'm still writing to a static field from an instance method, just via a static method - no?

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  • How to properly set a datatable to an gridview in code with an ObjectDataSource?

    - by Xaisoft
    Hello, I have an ObjectDataSource with an ID of ObjectDataSource1 on a webpage. I also have a gridview in which I am binding the ObjectDataSource.ID to the GridView.DataSourceID. The problem I get is when text is changed in a textbox, the code calls BrokerageTransactions.GetAllWithDt which returns a DataTable. I want to set this datatable as the DataSource for the GridView, but it is telling me that I can't set the DataSouce and DataSourceId together. How can I fix this? Code is below. Also. Why can't you set a DataSourceID and a DataSource when using an ObjectDataSource? Thanks, X protected void BrokerageChange(Object sender, EventArgs e) { BrokerageTransactions brokerageaccountdetails = new BrokerageTransactions(); DataSet ds = BrokerageAccount.GetBrkID2(new Guid(Membership.GetUser().ProviderUserKey.ToString()), ddlBrokerageDetails.SelectedItem.Text.ToString()); foreach (DataRow dr in ds.Tables[0].Rows) { brokerageaccountdetails.BrokerageId = new Guid(dr["BrkrgId"].ToString()); } ddlBrokerageDetails.SelectedItem.Value = brokerageaccountdetails.BrokerageId.ToString(); if (txtTransactionsTo.Text != "" && txtTransactionsFrom.Text != "") ObjectDataSource1.FilterExpression = "convert(CreateDt,System.DateTime)>Convert('" + Convert.ToDateTime(txtTransactionsFrom.Text) + "',System.DateTime) and Convert(CreateDt,System.DateTime)<convert('" + Convert.ToDateTime(txtTransactionsTo.Text.ToString()) + "',System.DateTime)"; else if (txtTransactionsFrom.Text != "") ObjectDataSource1.FilterExpression = "convert(CreateDt,System.DateTime)>convert('" + Convert.ToDateTime(txtTransactionsFrom.Text) + "',System.DateTime)"; else if (txtTransactionsTo.Text != "") ObjectDataSource1.FilterExpression = "convert(CreateDt,System.DateTime) <convert('" + Convert.ToDateTime(txtTransactionsTo.Text.ToString()) + "',System.DateTime)"; else ObjectDataSource1.FilterExpression = " "; grvBrokerage.DataSourceID = ObjectDataSource1.ID; grvBrokerage.DataBind(); DateTime dtTransFrom = Convert.ToDateTime("1/1/1900"); DateTime dtTransTo = System.DateTime.Today; //TransactionsTo Box is Empty if ((txtTransactionsFrom.Text.Length > 2) && (txtTransactionsTo.Text.Length < 2)) { dtTransFrom = Convert.ToDateTime(txtTransactionsFrom.Text); dtTransTo = System.DateTime.Today; } //TransactionsFrom Box is Empty if ((txtTransactionsFrom.Text.Length < 2) && (txtTransactionsTo.Text.Length > 2)) { dtTransFrom = Convert.ToDateTime("1/1/1900"); dtTransTo = Convert.ToDateTime(txtTransactionsTo.Text); } //TransactionsFrom Box and TransactionsTo Box is Not Empty if ((txtTransactionsFrom.Text.Length > 2) && (txtTransactionsTo.Text.Length > 2)) { dtTransFrom = Convert.ToDateTime(txtTransactionsFrom.Text); dtTransTo = Convert.ToDateTime(txtTransactionsTo.Text); } // Fails Here grvBrokerage.DataSource = BrokerageTransactions.GetAllWithDt(brokerageaccountdetails.BrokerageId, dtTransFrom, dtTransTo); grvBrokerage.DataBind(); }

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  • How to convert an existing callback interface to use boost signals & slots

    - by the_mandrill
    I've currently got a class that can notify a number of other objects via callbacks: class Callback { virtual NodulesChanged() =0; virtual TurkiesTwisted() =0; }; class Notifier { std::vector<Callback*> m_Callbacks; void AddCallback(Callback* cb) {m_Callbacks.push(cb); } ... void ChangeNodules() { for (iterator it=m_Callbacks.begin(); it!=m_Callbacks.end(); it++) { (*it)->NodulesChanged(); } } }; I'm considering changing this to use boost's signals and slots as it would be beneficial to reduce the likelihood of dangling pointers when the callee gets deleted, among other things. However, as it stands boost's signals seems more oriented towards dealing with function objects. What would be the best way of adapting my code to still use the callback interface but use signals and slots to deal with the connection and notification aspects?

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  • Automatically generate buddy classes from model in C#

    - by JohnnyO
    I use Linq to Sql (although this is equally applicable in Entity Framework) for my models, and I'm finding myself creating buddy classes for my models all the time. I find this time consuming and repetitive. Is there an easy way to automatically generate these buddy classes based on the models? Perhaps a visual studio macro? An example of a buddy class that I'd like to create: [MetadataType(typeof(PersonMetadata))] public partial class Person { } public class PersonMetadata { public object Id { get; set; } public object FirstName { get; set; } } Thanks in advance.

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  • Why does this IF statement fail?

    - by ChosenOne
    If variable path is empty, and editor.Text is not empty, the SaveFileDialog should be displayed. Now, why on earth is this damn thing failing??? I have tried this with many different variations of code with the same result: FAIL: if(path.Length >= 1) // path contains a path. Save changes instead of creating NEW file. { File.WriteAllText(path, content); } else { // no path defined. Create new file and write to it. using(SaveFileDialog saver = new SaveFileDialog()) { if(saver.ShowDialog() == DialogButtons.OK) { File.WriteAllText(saver.Filename, content); } } } At the top of code file I have: path = String.Empty; So why the heck it this failing every single time, even after trying all of the below variations? if(path.Length > 1) // path contains a path. Save changes instead of creating NEW file. { File.WriteAllText(path, content); } else { // no path defined. Create new file and write to it. using(SaveFileDialog saver = new SaveFileDialog()) { if(saver.ShowDialog() == DialogButtons.OK) { File.WriteAllText(saver.Filename, content); } } } and if(String.IsNullOrEmpty(path)) // path contains a path. Save changes instead of creating NEW file. { File.WriteAllText(path, content); } else { // no path defined. Create new file and write to it. using(SaveFileDialog saver = new SaveFileDialog()) { if(saver.ShowDialog() == DialogButtons.OK) { File.WriteAllText(saver.Filename, content); } } } and if(String.IsNullOrWhiteSpace(path)) // path contains a path. Save changes instead of creating NEW file. { File.WriteAllText(path, content); } else { // no path defined. Create new file and write to it. using(SaveFileDialog saver = new SaveFileDialog()) { if(saver.ShowDialog() == DialogButtons.OK) { File.WriteAllText(saver.Filename, content); } } } This is making me very angry. How could this fail? Setting a break point reveals that path is definitely null/"".

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