RadDropDownButton prevent close?

[David A.]

Hi,
I have a RadDropDownButton and am using the menum items as a checklist.  The problem is I would like to keep the drop down open until the button is clicked again to allow the user to select multiple items.

Is this possible?

Thank you,
David

[Stefan]

Hi David,

Thank you for writing.

You can achieve the desired functionality by canceling the popup closing in the DropDownClosing event handler of DropDownButtonElement except when a flag raised in the MouseDown event of the DropDownButtonElement is true. Here is a sample:

public Form1()
{
    InitializeComponent();

    foreach (RadMenuItem item in radDropDownButton1.Items)
    {
        item.CheckOnClick = true;
    }

    radDropDownButton1.DropDownButtonElement.MouseDown += new MouseEventHandler(DropDownButtonElement_MouseDown);
    radDropDownButton1.DropDownButtonElement.DropDownClosing+=new RadPopupClosingEventHandler(DropDownButtonElement_DropDownClosing);
}

private bool preventClose = false;

void DropDownButtonElement_MouseDown(object sender, MouseEventArgs e)
{
    if (radDropDownButton1.DropDownButtonElement.IsDropDownShown)
    {
        preventClose = true;
    }
}

void DropDownButtonElement_DropDownClosing(object sender, RadPopupClosingEventArgs args)
{
    if (preventClose)
    {
        preventClose = false;
        return;
    }
    args.Cancel = true;
}

I hope that you find this information helpful. Should you have any other questions, do not hesitate to contact us.
 
Greetings,
Stefan
the Telerik team