ComboBox OnPropertyChang ed problem

[Gerrit]

Hi,

I try to learn programming in c# with databinding controls. Now I have a
problem with a ComboBox with the advanced properties for databinding, I
want to set the DataSourceUpdat eMode to OnPropertyChang ed, but then the
combobox does not display the right displaymember.

Below is my sample code (it is working, when you paste it in a new
windowsapplicat ion, in a form and delete some generated code, but it is not
a useful program but it shows my problem). When the checkbox
OnPropertyChang ed is unchecked, you have to click in an other control to see
the changes, but the right displaymember is showed. With OnPropertyChang ed
checked the program react immedealtly but not the right displaymember is
showed.

Who can give me a hint for this problem? Thanks.

using System;
using System.Collecti ons.Generic;
using System.Componen tModel;
using System.Data;
using System.Drawing;
using System.Text;
using System.Windows. Forms;

namespace ComboBoxTest
{
public class Form1 : Form
{
/// <summary>
/// Required designer variable.
/// </summary>
private System.Componen tModel.IContain er components = null;

/// <summary>
/// Clean up any resources being used.
/// </summary>
/// <param name="disposing ">true if managed resources should be
disposed; otherwise, false.</param>
protected override void Dispose(bool disposing)
{
if (disposing && (components != null))
{
components.Disp ose();
}
base.Dispose(di sposing);
}

#region Windows Form Designer generated code

/// <summary>
/// Required method for Designer support - do not modify
/// the contents of this method with the code editor.
/// </summary>
private void InitializeCompo nent()
{
this.components = new System.Componen tModel.Containe r();
System.Windows. Forms.Label nameLabel;
System.Windows. Forms.Label kindLabel;
System.Windows. Forms.Label speedLabel;
this.nameTextBo x = new System.Windows. Forms.TextBox() ;
this.gameBindin gSource = new
System.Windows. Forms.BindingSo urce(this.compo nents);
this.kindComboB ox = new System.Windows. Forms.ComboBox( );
this.kindListBi ndingSource = new
System.Windows. Forms.BindingSo urce(this.compo nents);
this.speedTextB ox = new System.Windows. Forms.TextBox() ;
this.checkBox1 = new System.Windows. Forms.CheckBox( );
nameLabel = new System.Windows. Forms.Label();
kindLabel = new System.Windows. Forms.Label();
speedLabel = new System.Windows. Forms.Label();
((System.Compon entModel.ISuppo rtInitialize)(t his.gameBinding Source)).BeginI nit();
((System.Compon entModel.ISuppo rtInitialize)(t his.kindListBin dingSource)).Be ginInit();
this.SuspendLay out();
//
// nameLabel
//
nameLabel.AutoS ize = true;
nameLabel.Locat ion = new System.Drawing. Point(26, 22);
nameLabel.Name = "nameLabel" ;
nameLabel.Size = new System.Drawing. Size(38, 13);
nameLabel.TabIn dex = 1;
nameLabel.Text = "Name:";
//
// kindLabel
//
kindLabel.AutoS ize = true;
kindLabel.Locat ion = new System.Drawing. Point(33, 48);
kindLabel.Name = "kindLabel" ;
kindLabel.Size = new System.Drawing. Size(31, 13);
kindLabel.TabIn dex = 2;
kindLabel.Text = "Kind:";
//
// speedLabel
//
speedLabel.Auto Size = true;
speedLabel.Loca tion = new System.Drawing. Point(23, 75);
speedLabel.Name = "speedLabel ";
speedLabel.Size = new System.Drawing. Size(41, 13);
speedLabel.TabI ndex = 4;
speedLabel.Text = "Speed:";
//
// nameTextBox
//
this.nameTextBo x.DataBindings. Add(new
System.Windows. Forms.Binding(" Text", this.gameBindin gSource, "Name", true));
this.nameTextBo x.Location = new System.Drawing. Point(70, 19);
this.nameTextBo x.Name = "nameTextBo x";
this.nameTextBo x.Size = new System.Drawing. Size(100, 20);
this.nameTextBo x.TabIndex = 2;
//
// gameBindingSour ce
//
this.gameBindin gSource.DataSou rce = typeof(ComboBox Test.Game);
//
// kindComboBox
//
this.kindComboB ox.DataBindings .Add(new
System.Windows. Forms.Binding(" SelectedValue", this.gameBindin gSource,
"Kind", true));
this.kindComboB ox.DataSource = this.kindListBi ndingSource;
this.kindComboB ox.DisplayMembe r = "Descriptio n";
this.kindComboB ox.FormattingEn abled = true;
this.kindComboB ox.Location = new System.Drawing. Point(70, 45);
this.kindComboB ox.Name = "kindComboB ox";
this.kindComboB ox.Size = new System.Drawing. Size(121, 21);
this.kindComboB ox.TabIndex = 3;
this.kindComboB ox.ValueMember = "IdKind";
//
// kindListBinding Source
//
this.kindListBi ndingSource.Dat aMember = "KindList";
this.kindListBi ndingSource.Dat aSource = this.gameBindin gSource;
//
// speedTextBox
//
this.speedTextB ox.DataBindings .Add(new
System.Windows. Forms.Binding(" Text", this.gameBindin gSource, "Speed",
true));
this.speedTextB ox.DataBindings .Add(new
System.Windows. Forms.Binding(" Enabled", this.gameBindin gSource,
"IsSpeedEnabled ", true));
this.speedTextB ox.Location = new System.Drawing. Point(70, 72);
this.speedTextB ox.Name = "speedTextB ox";
this.speedTextB ox.Size = new System.Drawing. Size(100, 20);
this.speedTextB ox.TabIndex = 5;
//
// checkBox1
//
this.checkBox1. AutoSize = true;
this.checkBox1. Location = new System.Drawing. Point(70, 99);
this.checkBox1. Name = "checkBox1" ;
this.checkBox1. Size = new System.Drawing. Size(122, 17);
this.checkBox1. TabIndex = 6;
this.checkBox1. Text = "OnPropertyChan ged";
this.checkBox1. UseVisualStyleB ackColor = true;
this.checkBox1. CheckedChanged += new
System.EventHan dler(this.check Box1_CheckedCha nged);
//
// Form1
//
this.AutoScaleD imensions = new System.Drawing. SizeF(6F, 13F);
this.AutoScaleM ode = System.Windows. Forms.AutoScale Mode.Font;
this.ClientSize = new System.Drawing. Size(213, 129);
this.Controls.A dd(this.checkBo x1);
this.Controls.A dd(speedLabel);
this.Controls.A dd(this.speedTe xtBox);
this.Controls.A dd(kindLabel);
this.Controls.A dd(this.kindCom boBox);
this.Controls.A dd(nameLabel);
this.Controls.A dd(this.nameTex tBox);
this.Name = "Form1";
this.Text = "Games";
((System.Compon entModel.ISuppo rtInitialize)(t his.gameBinding Source)).EndIni t();
((System.Compon entModel.ISuppo rtInitialize)(t his.kindListBin dingSource)).En dInit();
this.ResumeLayo ut(false);
this.PerformLay out();

}

#endregion

private System.Windows. Forms.BindingSo urce gameBindingSour ce;
private System.Windows. Forms.TextBox nameTextBox;
private System.Windows. Forms.ComboBox kindComboBox;
private System.Windows. Forms.TextBox speedTextBox;
private System.Windows. Forms.BindingSo urce kindListBinding Source;

public Form1()
{
InitializeCompo nent();

Game game = new Game();
game.Name = "Test game";
game.Kind = 1;
gameBindingSour ce.DataSource = game;
}

private CheckBox checkBox1;

private void checkBox1_Check edChanged(objec t sender, EventArgs e)
{
if (checkBox1.Chec ked)
this.kindComboB ox.DataBindings[0].DataSourceUpda teMode =
DataSourceUpdat eMode.OnPropert yChanged;
else
this.kindComboB ox.DataBindings[0].DataSourceUpda teMode =
DataSourceUpdat eMode.OnValidat ion;
}
}

static class Program
{
/// <summary>
/// The main entry point for the application.
/// </summary>
[STAThread]
static void Main()
{
Application.Ena bleVisualStyles ();
Application.Set CompatibleTextR enderingDefault (false);
Application.Run (new Form1());
}
}

public class Game
{
private string name;
private int kind;
private List<KindkindLi st = new List<Kind>();
private int speed;
private bool isSpeedEnabled;

public Game()
{
KindList.Add(ne w Kind(0, "Adventure" ));
KindList.Add(ne w Kind(1, "Racing"));
}

public string Name
{
get { return name; }
set { name = value; }
}

public int Kind
{
get { return kind; }
set
{
kind = value;
isSpeedEnabled = (kind == 1);
}
}

public List<KindKindLi st
{
get { return kindList; }
set { kindList = value; }
}

public int Speed
{
get { return speed; }
set { speed = value; }
}

public bool IsSpeedEnabled
{
get
{
return isSpeedEnabled;
}
set { isSpeedEnabled = value; }
}
}

public class Kind
{
private int idKind;
private string description;

public Kind(int IdKind, string Description)
{
this.IdKind = IdKind;
this.Descriptio n = Description;
}

public int IdKind
{
get { return idKind; }
set { idKind = value; }
}

public string Description
{
get { return description; }
set { description = value; }
}
}
}

--

www.gsnel.nl

[Cor Ligthert[MVP]]

Gerrit,

If you want answers from these newsgroups, than create a piece of sample
code and show that to us, not a complete program. Mostly if you do that you
see often yourself the problem.

The change that you get an answer now, is probably only from somebody who is
learning as well C# and tries your program.

As well tell what you want to achieve, not a piece of code that does not
work in the way you think that it should work.

Cor

[GS]

"Cor Ligthert[MVP]" <no************ @planet.nlschre ef in bericht
news:4D******** *************** ***********@mic rosoft.com...

Gerrit,

If you want answers from these newsgroups, than create a piece of sample
code and show that to us, not a complete program. Mostly if you do that
you see often yourself the problem.

The change that you get an answer now, is probably only from somebody who
is learning as well C# and tries your program.

As well tell what you want to achieve, not a piece of code that does not
work in the way you think that it should work.

Cor

Ok, but I described my problem / what I want in the first rows of my
question. But my english is not so good, so I post the code with it.
I try again: I want that the selectionchange of the combobox do directly
something when the selection changed. And not by leaving the combobox with
tab or mouseclick. So I try to set the DataSourceUpdat eMode to
OpPropertyChang ed. I have a databound combobox, bounded and in the bounded
object, I see the change, but the selected item of the combobox does not
change.

I fill the combobox items with a list property:

public List<KindKindLi st
{
get { return kindList; }
set { kindList = value; }
}

And the value is set in al property:

public int Kind
{
get { return kind; }
set
{
kind = value;
isSpeedEnabled = (kind == 1);
}
}

And when Kind is 1, then I set an other property to true

public bool IsSpeedEnabled
{
get
{
return isSpeedEnabled;
}
set { isSpeedEnabled = value; }
}

So with this property, I can enable fields, that only must be enabled when
Kind == 1.

[GS]

I fill the combobox items with a list property:

public List<KindKindLi st
{
get { return kindList; }
set { kindList = value; }
}

And the value is set in al property:

public int Kind
{
get { return kind; }
set
{
kind = value;
isSpeedEnabled = (kind == 1);
}
}

And when Kind is 1, then I set an other property to true

public bool IsSpeedEnabled
{
get
{
return isSpeedEnabled;
}
set { isSpeedEnabled = value; }
}

So with this property, I can enable fields, that only must be enabled when
Kind == 1.

Some more information:

I bound the ComboBox with a BindingSource, then I have the problem. But when
I bound it to my object, then I have not the problem.

Is the right way, binding to the object or is BindingSource better and how
can I do that?