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ToolStripDropDownItem.DropDownOpening Event

Occurs as the ToolStripDropDown is opening.

Namespace:  System.Windows.Forms
Assembly:  System.Windows.Forms (in System.Windows.Forms.dll)

public event EventHandler DropDownOpening

For more information about handling events, see Consuming Events.

The following code example demonstrates the use of this member. In the example, an event handler reports on the occurrence of the DropDownOpening event. This report helps you to learn when the event occurs and can assist you in debugging. To report on multiple events or on events that occur frequently, consider replacing MessageBox.Show with Console.WriteLine or appending the message to a multiline TextBox.

To run the example code, paste it into a project that contains an instance of a type that inherits from ToolStripDropDownItem, such as a ToolStripMenuItem or ToolStripDropDownButton. Then name the instance ToolStripDropDownItem1 and ensure that the event handler is associated with the DropDownOpening event.


private void ToolStripDropDownItem1_DropDownOpening(Object sender, EventArgs e) {

   MessageBox.Show("You are in the ToolStripDropDownItem.DropDownOpening event.");

}


.NET Framework

Supported in: 4, 3.5, 3.0, 2.0

.NET Framework Client Profile

Supported in: 4, 3.5 SP1

Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows XP SP2 x64 Edition, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2

The .NET Framework does not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.
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