MethodInvoker Delegate
Definition
Represents a delegate that can execute any method in managed code that is declared void and takes no parameters.
public delegate void MethodInvoker();
public delegate void MethodInvoker();
type MethodInvoker = delegate of unit -> unit
Public Delegate Sub MethodInvoker()
- Inheritance
Examples
The following code example demonstrates how to use a MethodInvoker to call a method that updates the title bar of the application form.
public partial class Form1 : Form
{
public Form1()
{
// Create a timer that will call the ShowTime method every second.
var timer = new System.Threading.Timer(ShowTime, null, 0, 1000);
}
private void ShowTime(object x)
{
// Don't do anything if the form's handle hasn't been created
// or the form has been disposed.
if (!this.IsHandleCreated || this.IsDisposed) return;
// Invoke an anonymous method on the thread of the form.
this.Invoke((MethodInvoker) delegate
{
// Show the current time in the form's title bar.
this.Text = DateTime.Now.ToLongTimeString();
});
}
}
Partial Public Class Form1
Inherits System.Windows.Forms.Form
Public Sub New()
' Create a timer that will call the ShowTime method every second.
Dim timer As System.Threading.Timer = _
New System.Threading.Timer(AddressOf ShowTime, Nothing, 0, 1000)
End Sub
Sub ShowTime(ByVal x As Object)
' Don't do anything if the form's handle hasn't been created
' or the form has been disposed.
If (Not Me.IsHandleCreated OrElse Me.IsDisposed) Then Return
' Create the method invoker.
' The method body shows the current time in the forms title bar.
Dim mi As MethodInvoker = AddressOf UpdateFormText
Me.Invoke(mi)
End Sub
Sub UpdateFormText()
Me.Text = DateTime.Now.ToLongTimeString()
End Sub
End Class
Remarks
MethodInvoker provides a simple delegate that is used to invoke a method with a void parameter list. This delegate can be used when making calls to a control's Invoke method, or when you need a simple delegate but do not want to define one yourself.
Extension Methods
GetMethodInfo(Delegate) |
Gets an object that represents the method represented by the specified delegate. |