How to prevent Mouse Scroll in ToolStripComboBox?
I am trying to disable Mouse Scroll in my ToolStripComboBox, I thought I can catch the Mouse Wheel event, but while the event is available for ComboBox, it is not开发者_运维技巧 available instead for the ToolStripComboBox. Any ideas?
The ToolStripComboBox
helpfully exposes its underlying ComboBox
control in its aptly named ComboBox
property. This allows us to access its properties, methods, and events that were not been wrapped into the ToolStripComboBox
.
And, as you probably know, the standard ComboBox
control exposes a MouseWheel
event that fires each time the mouse wheel is scrolled while the combo box has focus.
Putting these two things together, we can add a handler for the ToolStripComboBox
control's underlying ComboBox
control's MouseWheel
event, and override its default behavior.
So, assuming you have a form that contains a ToolStrip
and a ToolStripComboBox
, you can use something like the following code:
public partial class Form1 : Form
{
public Form1()
{
InitializeComponent();
//Attach a handler for the MouseWheel event
ToolStripComboBox1.ComboBox.MouseWheel += new MouseEventHandler(ToolStripComboBox_MouseWheel);
}
private void ToolStripComboBox_MouseWheel(object sender, MouseEventArgs e)
{
//Cast the MouseEventArgs to HandledMouseEventArgs
HandledMouseEventArgs mwe = (HandledMouseEventArgs)e;
//Indicate that this event was handled
//(prevents the event from being sent to its parent control)
mwe.Handled = true;
}
}
Alternatively, of course, you could always subclass the existing ToolStripComboBox
control and override its behavior there in the same way shown above.
In addition to what Cody Gray suggested you may want the wheel scolling to work when the combobox is dropped. Just chech the DroppedDown state in MouseWheel handle:
public class MyToolStripComboBox : ToolStripComboBox
{
public MyToolStripComboBox()
{
this.ComboBox.MouseWheel += new MouseEventHandler(ComboBox_MouseWheel);
}
void ComboBox_MouseWheel(object sender, MouseEventArgs e)
{
if (!this.ComboBox.DroppedDown)
((HandledMouseEventArgs)e).Handled = true;
}
}
Scrolling dropped combobox with wheel doesn't change the selection, so it works as expected
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