Unexpected events are raised when you switch between tab pages with a ComboBox or a ListBox control (820633)

MORE INFORMATION

Steps to reproduce the behavior

Create the form and add the controls

1. In Visual Studio 2005 or in Visual Studio .NET 2003, create a new Windows Application project by using Microsoft Visual Basic 2005, Microsoft Visual Basic .NET, or Microsoft Visual C# .NET. By default, Form1 is created.
2. Add a TabControl control to Form1. The TabControl1 control is created.
3. Right-click the TabControl1 control, and then click Properties.
4. In the Properties window, click to select the TabPages property, and then click the ellipsis (...) button.
5. In the TabPage Collection Editor dialog box, click Add two times, and then click OK.
   By default, the TabPage1 and TabPage2 properties are created.
6. Click the TabPage2 property. Add a ListBox control to the TabControl1 control.
7. In the Properties window of ListBox1, click to select the Items property, and then click the ellipsis (...) button.
8. In the String Collection Editor dialog box, type item1, item2, item3, and then click OK.

Add code for the events in the ListBox control

1. Add the following code to the BindingContextChanged event of the ListBox1 control.
   
   Visual Basic 2005 or Visual Basic .NET code

    'Print the output in the console when the event is raised.
           Console.WriteLine("BindingContext changed.")

   Visual C# .NET code

   //Print the output in the console when the event is raised.
           Console.WriteLine("BindingContext changed.");

2. Add the following code to the SelectedValueChanged event of the ListBox1 control.
   
   Visual Basic 2005 or Visual Basic .NET code

    'Print the output in the console when the event is raised.
           Console.WriteLine("SelectedValue changed.")

   Visual C# .NET code

   //Print the output in the console when the event is raised.
           Console.WriteLine("SelectedValue changed.");

3. Add the following code to the SelectedIndexChanged event of the ListBox1 control.
   
   Visual Basic 2005 or Visual Basic .NET code

    'Print the output in the console when the event is raised.
           Console.WriteLine("SelectedIndex changed.")

   Visual C# .NET code

   //Print the output in the console when the event is raised.
           Console.WriteLine("SelectedIndex changed.");

4. In Solution Explorer, right-click WindowsApplication1, and then click Properties.
5. In the Output type list, select Console Application, and then click OK.

Build the project

1. On the Build menu, click Build Solution.
2. On the Debug menu, click Start. Notice that the BindingContextChanged event is raised one time.
3. Click TabPage2. The BindingContextChanged event is raised multiple times.
4. Click TabPage1, and then click TabPage2. The BindingContextChanged event is raised only one time. Notice the output when you switch tab pages repeatedly.

Add a database connection

1. Return to Form Designer.
2. On the View menu, click Server Explorer.
3. In Server Explorer, right-click Data Connections, and then click Add Connection.
4. On the Connection tab, type your server name, select the Northwind database from the list, and then click OK.
5. Expand Data Connections, and then expand your server name.
6. Expand Tables, and then add the Customers table to Form1.
7. Right-click SqlDataAdapter1, and then click Generate Dataset.
8. In the Generate Dataset dialog box, click OK.
9. In the Properties window of the ListBox1 control, set the DataSource property to DataSet11.Customers, and then set the DisplayMember property to City.
10. Add the following code to the Form1_Load event handler.
    
    Visual Basic 2005 or Visual Basic .NET code

     SqlDataAdapter1.Fill(DataSet11)

    Visual C# .NET code

    sqlDataAdapter1.Fill(dataSet11);

11. On the Debug menu, click Start.
12. The BindingContextChanged, the SelectedValueChanged, and the SelectedIndexChanged events are raised multiple times. Notice the output when you switch tab pages repeatedly. The events are raised only one time.
    
    Note Notice the output in Visual Studio .NET 2003. The BindingContextChanged and the SelectedValueChanged events are raised multiple times. Notice the output when you switch tab pages repeatly. The events are raised only one time.
    
    Select an item from the list in the ListBox control, and then switch the tab pages. Only the BindingContextChanged event is raised.