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Can't override CultureInfo.ToStringI am having difficulty overriding the ToString() method of CultureInfo using Visual Studio 2005. Exactly the same code works fine with Visual Studio .NET 2003. What I am doing is adding objects which are derived from CultureInfo to a ListBox. I want the language name to be displayed in the native language, so I override the ToString() method to access the CultureInfo.NativeName property. I can reproduce the problem with a simple example. Create a windows forms project in VB.NET and add a single list box to the form. Paste the following code into the file Form1.vb (replacing the existing code). Imports System.Globalization Public Class Form1 Private Class CultureListInfo Inherits CultureInfo Public Sub New ( Byval Name as String ) MyBase.New ( Name ) End Sub Public Overrides Function ToString() as String return NativeName End Function End Class Private Sub Form1_Load( ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load ListBox1.Items.Add ( new CultureListInfo ( "de" ) ) ListBox1.Items.Add ( new CultureListInfo ( "es" ) ) ListBox1.Items.Add ( new CultureListInfo ( "fr" ) ) End Sub End Class My understanding is that the ListBox will use the ToString() method to generate the text shown in the list box. However, the ToString() method is never entered. I have almost identical code in C# which works fine, and the above code worked with VS 2003. What is wrong? Phil Hi,
You may override DisplayName property to change the item in ListBox. The specification might have been changed. -- Yuichiro Ochifuji JAPAN I am not good at English.(^^; Thanks a lot. I have now used the code
Public Overrides ReadOnly Property DisplayName() As String Get Return MyBase.NativeName End Get End Property instead of Public Overrides Function ToString() As String Return MyBase.NativeName() End Function and this version works. I don't think that they have changed the specification. MICROSOFT ARE YOU LISTENING? I think they have broken it. Best regards Phil Show quoteHide quote "Yuichiro Ochifuji" <ochif***@japan.interq.or.jp> wrote in message news:%23VUgCAC$GHA.1196@TK2MSFTNGP02.phx.gbl... > Hi, > > You may override DisplayName property to change the item in ListBox. > The specification might have been changed. > > -- > Yuichiro Ochifuji > JAPAN > I am not good at English.(^^; Phil,
What does your C# code look like? > My understanding is that the ListBox will use the ToString() method to That is my understanding also. Although using your code I get the same > generate the text shown in the list box. However, the ToString() method is > never entered. results. It feels like a bug. Have you submitted something on http://connect.microsoft.com/ The following demonstrates that your code is working: Dim item As CultureInfo item = New CultureListInfo("de") Debug.WriteLine(item, "Object.ToString()") Debug.WriteLine(item.ToString(), "CultureInfo.ToString()") Prints: Object.ToString(): Deutsch CultureInfo.ToString(): Deutsch Have you considered simply: Protected Overrides Sub OnLoad(ByVal e As System.EventArgs) MyBase.OnLoad(e) ListBox1.Items.Add(New CultureInfo("de")) ListBox1.Items.Add(New CultureInfo("es")) ListBox1.Items.Add(New CultureInfo("fr")) ListBox1.DisplayMember = "NativeName" End Sub -- Show quoteHide quoteHope this helps Jay B. Harlow ..NET Application Architect, Enthusiast, & Evangelist T.S. Bradley - http://www.tsbradley.net "Phil Jollans" <nospam@jollans.com> wrote in message news:ei32ug$2ot$03$1@news.t-online.com... > Hi, > > I am having difficulty overriding the ToString() method of CultureInfo > using > Visual Studio 2005. > > Exactly the same code works fine with Visual Studio .NET 2003. > > What I am doing is adding objects which are derived from CultureInfo to a > ListBox. I want the language name to be displayed in the native language, > so > I override the ToString() method to access the CultureInfo.NativeName > property. > > I can reproduce the problem with a simple example. > > Create a windows forms project in VB.NET and add a single list box to the > form. > Paste the following code into the file Form1.vb (replacing the existing > code). > > > Imports System.Globalization > > Public Class Form1 > > Private Class CultureListInfo > Inherits CultureInfo > > Public Sub New ( Byval Name as String ) > MyBase.New ( Name ) > End Sub > > Public Overrides Function ToString() as String > return NativeName > End Function > > End Class > > Private Sub Form1_Load( ByVal sender As System.Object, ByVal e As > System.EventArgs) Handles MyBase.Load > > ListBox1.Items.Add ( new CultureListInfo ( "de" ) ) > ListBox1.Items.Add ( new CultureListInfo ( "es" ) ) > ListBox1.Items.Add ( new CultureListInfo ( "fr" ) ) > > End Sub > > End Class > > > My understanding is that the ListBox will use the ToString() method to > generate the text shown in the list box. However, the ToString() method is > never entered. > > I have almost identical code in C# which works fine, and the above code > worked with VS 2003. > > What is wrong? > > Phil > > > Hi Jay,
The C# class is private class CultureListInfo : CultureInfo { public CultureListInfo ( string Name ) : base ( Name ) {} public override String ToString() { return NativeName ; } } I havn't created the same example project. The suggestion with the DisplayMember property is clearly the easiest method. I was not familiar with this property. Originally, I started using the nested class with Visual Studio 2002. Did the DisplayMember exist back then? I have posted this issue at https://connect.microsoft.com/VisualStudio/feedback/ViewFeedback.aspx?FeedbackID=235465 since I still think it is a bug. Now I have two good alternatives so it is not at all urgent. Phil > Originally, I started using the nested class with Visual Studio 2002. Did
> the DisplayMember exist back then? Yes. --
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Hope this helps Jay B. Harlow ..NET Application Architect, Enthusiast, & Evangelist T.S. Bradley - http://www.tsbradley.net "Phil Jollans" <nospam@jollans.com> wrote in message
news:eihujs$noj$01$1@news.t-online.com... > Hi Jay, > > The C# class is > > private class CultureListInfo : CultureInfo > { > public CultureListInfo ( string Name ) : base ( Name ) {} > public override String ToString() > { > return NativeName ; > } > } > > I havn't created the same example project. > > The suggestion with the DisplayMember property is clearly the easiest > method. I was not familiar with this property. Originally, I started using > the nested class with Visual Studio 2002. Did the DisplayMember exist back > then? > > I have posted this issue at > https://connect.microsoft.com/VisualStudio/feedback/ViewFeedback.aspx?FeedbackID=235465 > since I still think it is a bug. Now I have two good alternatives so it is > not at all urgent. > > Phil > There seems to be two problems here. The first is that ListBox uses
ToString method of the object unless a member name within the object is specified in the DisplayMember property." isn't the whole story. If ListBox can convert from your type to String it will do that instead of using ToString(). The second problem is that CultureInfo defines a converter called CultureInfoConverter that is used to convert the CultureInfo object to a String object, completely bypassing the ToString method and using the DisplayName method. -- Show quoteHide quoteBrowse http://connect.microsoft.com/VisualStudio/feedback/ and vote. http://www.peterRitchie.com/blog/ Microsoft MVP, Visual Developer - Visual C# "Phil Jollans" wrote: > Hi, > > I am having difficulty overriding the ToString() method of CultureInfo using > Visual Studio 2005. > > Exactly the same code works fine with Visual Studio .NET 2003. > > What I am doing is adding objects which are derived from CultureInfo to a > ListBox. I want the language name to be displayed in the native language, so > I override the ToString() method to access the CultureInfo.NativeName > property. > > I can reproduce the problem with a simple example. > > Create a windows forms project in VB.NET and add a single list box to the > form. > Paste the following code into the file Form1.vb (replacing the existing > code). > > > Imports System.Globalization > > Public Class Form1 > > Private Class CultureListInfo > Inherits CultureInfo > > Public Sub New ( Byval Name as String ) > MyBase.New ( Name ) > End Sub > > Public Overrides Function ToString() as String > return NativeName > End Function > > End Class > > Private Sub Form1_Load( ByVal sender As System.Object, ByVal e As > System.EventArgs) Handles MyBase.Load > > ListBox1.Items.Add ( new CultureListInfo ( "de" ) ) > ListBox1.Items.Add ( new CultureListInfo ( "es" ) ) > ListBox1.Items.Add ( new CultureListInfo ( "fr" ) ) > > End Sub > > End Class > > > My understanding is that the ListBox will use the ToString() method to > generate the text shown in the list box. However, the ToString() method is > never entered. > > I have almost identical code in C# which works fine, and the above code > worked with VS 2003. > > What is wrong? > > Phil > > > > Peter,
Thanks for the heads up. I forget about Type Converters... -- Show quoteHide quoteHope this helps Jay B. Harlow ..NET Application Architect, Enthusiast, & Evangelist T.S. Bradley - http://www.tsbradley.net "Peter Ritchie [C# MVP]" <PRSoCo@newsgroups.nospam> wrote in message news:135A81A5-C149-492D-982D-5103A89BC93B@microsoft.com... > There seems to be two problems here. The first is that ListBox uses > ToString method of the object unless a member name within the object is > specified in the DisplayMember property." isn't the whole story. If > ListBox > can convert from your type to String it will do that instead of using > ToString(). > > The second problem is that CultureInfo defines a converter called > CultureInfoConverter that is used to convert the CultureInfo object to a > String object, completely bypassing the ToString method and using the > DisplayName method. > > -- > Browse http://connect.microsoft.com/VisualStudio/feedback/ and vote. > http://www.peterRitchie.com/blog/ > Microsoft MVP, Visual Developer - Visual C# > > > "Phil Jollans" wrote: > >> Hi, >> >> I am having difficulty overriding the ToString() method of CultureInfo >> using >> Visual Studio 2005. >> >> Exactly the same code works fine with Visual Studio .NET 2003. >> >> What I am doing is adding objects which are derived from CultureInfo to a >> ListBox. I want the language name to be displayed in the native language, >> so >> I override the ToString() method to access the CultureInfo.NativeName >> property. >> >> I can reproduce the problem with a simple example. >> >> Create a windows forms project in VB.NET and add a single list box to the >> form. >> Paste the following code into the file Form1.vb (replacing the existing >> code). >> >> >> Imports System.Globalization >> >> Public Class Form1 >> >> Private Class CultureListInfo >> Inherits CultureInfo >> >> Public Sub New ( Byval Name as String ) >> MyBase.New ( Name ) >> End Sub >> >> Public Overrides Function ToString() as String >> return NativeName >> End Function >> >> End Class >> >> Private Sub Form1_Load( ByVal sender As System.Object, ByVal e As >> System.EventArgs) Handles MyBase.Load >> >> ListBox1.Items.Add ( new CultureListInfo ( "de" ) ) >> ListBox1.Items.Add ( new CultureListInfo ( "es" ) ) >> ListBox1.Items.Add ( new CultureListInfo ( "fr" ) ) >> >> End Sub >> >> End Class >> >> >> My understanding is that the ListBox will use the ToString() method to >> generate the text shown in the list box. However, the ToString() method >> is >> never entered. >> >> I have almost identical code in C# which works fine, and the above code >> worked with VS 2003. >> >> What is wrong? >> >> Phil >> >> >> >> Hi Peter,
thats very interesting. However, it doesn't really explain: - why the behaviour appears to be different with VB and C# - why the behaviour has changed with VS 2005 More importantly, the Visual Studio Help really explains it differently. In the topic entitled: "How to: Add and Remove Items from a Windows Forms ComboBox, ListBox, or CheckedListBox Control" http://msdn2.microsoft.com/en-us/library/19fc31ss(VS.80).aspx it states "The items displayed are usually strings; however, any object can be used. The text that is displayed in the control is the value returned by the object's ToString method." You can't get much clearer than that. The ToString() method will be called, period. By the way, I remember exactly why I started using this method. Originally, I ported the code from VB6, where items in a ListBox control had an ..ItemData property. This disappeared in .NET, which was a bit of a pain. On the other hand, I can see that it makes sense that the item list is simply a list of objects. The recommended way to achieve the same functionality was to add objects to the list, containing any amount of "itemdata", and to implement a ToString method on the object. Phil 
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