Auto-dropdown GridViewComboBoxColumn on single-click?

[joseph_korn]

I am wondering if it is possible to have a GridViewComboBoxColumn that when clicked on, will automatically dropdown the list of choices for you to choose from (This saves one click when you are clicking many comboboxes in one go)? I imagine you would run the dropdown code in the CellBeginEdit event.. I am just not sure exactly how to accomplish this..

[Martin Vasilev]

Hi Joseph,

Thank you for the question.

You can show the drop down on first click by using RadComboBoxEditor's ShowDropDown() method in the CellEditorInitialized event. Please, review the following code-block:
 

private void radGridView1_CellEditorInitialized(object sender, GridViewCellEventArgs e)
{
    if ((this.radGridView1.ActiveEditor != null) &&
        (this.radGridView1.ActiveEditor is RadComboBoxEditor))
    {
        (this.radGridView1.ActiveEditor as RadComboBoxEditor).ShowDropDown();
    }
}

I hope this helps. If you have other questions, do not hesitate to contact me again.

 
Greetings,
Martin Vasilev
the Telerik team

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[Marina Vision]

This command doesn't work anymore:

(this.grdItems.ActiveEditor as RadComboBoxEditor).ShowDropDown();

I'm using Releases Q1-2010.
Was it replaced with a new command?

Thanks,
Marina

[Martin Vasilev]

Hi Marina Vision,

Thank you for writing.

In Q1 2010 release we have introduced a different editor structure and the implementation of the Auto-DropDown should be done in a different way, namely, by with using a custom combo-box editor. Please consider the following code snippet:

void radGridView1_EditorRequired(object sender, EditorRequiredEventArgs e)
{
    if (e.EditorType == typeof(RadComboBoxEditor))
    {
        e.Editor = new CustomComboEditor();
    }
}
class CustomComboEditor : RadComboBoxEditor
{
    public override void BeginEdit()
    {
        base.BeginEdit();
        ((RadComboBoxEditorElement)this.EditorElement).ShowPopup();
    }
}

Let me know if you have any additional questions.

Kind regards,
Martin Vasilev
the Telerik team

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[Jimmy]

I am trying to use a GridViewComboBoxColoumn in my Winform Application and I want to eliminate the 3 clicks it takes to select a value in the combo. 

Can I subscribe to an event and automatically show the combo?  

 

Thanks for your help,

Jimmy Voegele

 

 

[Dess | Tech Support Engineer, Principal]

Hello, Jimmy,   

In order to show the popup immediately after activating the editor you can use the following code snippet when handling the RadGridView.CellEditorInitialized event: 

private void radGridView1_CellEditorInitialized(object sender, GridViewCellEventArgs e)
{
    RadDropDownListEditor ddl = e.ActiveEditor as RadDropDownListEditor;
    if (ddl!=null)
    {
        RadDropDownListEditorElement el = ddl.EditorElement as RadDropDownListEditorElement;
        el.ShowPopup();
    }
}

In addition, you can subscribe to the CellClick event and force entering edit mode: 

           GridViewComboBoxColumn comboCol = new GridViewComboBoxColumn("CategoryName");
           comboCol.DataSource = this.categoriesBindingSource;
           comboCol.ValueMember = "CategoryID";
           comboCol.DisplayMember = "CategoryName";
           comboCol.FieldName = "CategoryID";
           comboCol.Width = 200;
           this.radGridView1.Columns.Add(comboCol);

private void radGridView1_CellClick(object sender, GridViewCellEventArgs e)
       {
           if (e.Column.HeaderText =="CategoryName")
           {
               this.radGridView1.BeginEdit();
           }
       }

Thus, only with a single click, you can activate the editor and show the drop down.

I hope this information helps. If you have any additional questions, please let me know. 

Regards,
Dess
Progress Telerik