X - prevent selectionindexchange_event trigger when assign datasource?

[The GridLock]

(Hi,

when I assign .datasouce by mousedown_event, it always sets item (0) from datasouce as the initial default value without blank text (It has the feeling that the user has not chosen but it has chosen before.) . Can I prevent this until the user chooses? because if so then selectedindexchanged will away run 2 times.

[Duraimurugan Vedagiri]

Hi GridLock,

You can achieve this by assigning the MultiColumnComboBox.SelectedIndex value as -1 and MultiColumnComboBox.Text as empty. Please refer the below code snippet for your reference.

Code Snippet

private void MultiColumnComboBox1_MouseDown(object sender, MouseEventArgs e) 

{ 

    if (this.multiColumnComboBox1.DataSource == null) 

    { 

        //Create dataTable 

        DataTable dt = new DataTable("Table1"); 

        dt.Columns.Add("FirstName"); 

        dt.Columns.Add("LastName"); 

 

        // Create a Data Set 

        DataSet ds = new DataSet(); 

        ds.Tables.Add(dt); 

        dt.Rows.Add(new string[] { "John", "Tina" }); 

        dt.Rows.Add(new string[] { "Mary", "Anu" }); 

        DataView view = new DataView(dt); 

 

        // DATASOURCE is DATAVIEW 

        this.multiColumnComboBox1.DataSource = view; 

        this.multiColumnComboBox1.DisplayMember = "FirstName"; 

        this.multiColumnComboBox1.ValueMember = "LastName"; 

        this.multiColumnComboBox1.SelectedIndex = -1; 

        this.multiColumnComboBox1.Text = string.Empty; 

    } 

} 

Regards,
Durai

[The GridLock]

It still looks quite clear Durai , I tried changing the fontcolor to white earlier to obscure it but it didn't work. I will live with it temporarily!

[Duraimurugan Vedagiri]

Hi GridLock,

Thanks for your update.

The MultiColumnComboBox default SelectedIndex is zero, so the first item is selected while assign the datasource. Also, you can prevent this with help of given snippet in the previous update.

Please let us know if you need any further assistance.

Regards,
Durai