ProcessMnemonic Method

ToolStripDropDown.ProcessMnemonic Method (Char)

 

Processes a mnemonic character.

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

[UIPermissionAttribute(SecurityAction.LinkDemand, Window = UIPermissionWindow.AllWindows)]
protected internal override bool ProcessMnemonic(
	char charCode
)

Parameters

charCode
Type: System.Char

The character to process.

Return Value

Type: System.Boolean

true if the character was processed as a mnemonic by the control; otherwise, false.

This method is called to give a control the opportunity to process a mnemonic character. The method should determine whether the control is in a state to process mnemonics and if whether the given character represents a mnemonic. If so, the method should perform the action associated with the mnemonic and return true. If not, the method should return false. Implementations of this method often use the IsMnemonic method to determine whether the given character matches a mnemonic in the control's text.

For example:

if (CanSelect && IsMnemonic(charCode, MyControl.Text) {
      // Perform action associated with mnemonic.
       }

This default implementation of the ProcessMnemonic method simply returns false to indicate that the control has no mnemonic.

The following code example demonstrates an extension of the button class that overrides the ProcessMnemonic method to exhibit custom behavior. The example also demonstrates the use of the CanSelect and IsMnemonic properties. To run this example, paste the following code after a form class, in the same file. Add a button of type MnemonicButton to the form.

// This button is a simple extension of the button class that overrides
// the ProcessMnemonic method.  If the mnemonic is correctly entered,  
// the message box will appear and the click event will be raised.  
public class MyMnemonicButton:Button

	// This method makes sure the control is selectable and the 
	// mneumonic is correct before displaying the message box
	// and triggering the click event.
{
	[UIPermission(
        SecurityAction.Demand, Window = UIPermissionWindow.AllWindows)]
        protected override bool ProcessMnemonic(char inputChar)
	{

		if (CanSelect&&IsMnemonic(inputChar, this.Text))
		{
			MessageBox.Show("You've raised the click event " +
				"using the mnemonic.");
			this.PerformClick();
			return true;
		}
		return false;
	}

}

UIPermission

for all windows for inheriting classes to call this method. Associated enumeration: AllWindows value of UIPermissionWindow.

.NET Framework
Available since 2.0
Return to top
Show:
© 2016 Microsoft