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UserControl.Load Event

  • Reference

Definition

Namespace:
System.Windows.Forms
Assembly:
System.Windows.Forms.dll
Source:
UserControl.cs
Source:
UserControl.cs
Source:
UserControl.cs

Occurs before the control becomes visible for the first time.

public:
 event EventHandler ^ Load;
public event EventHandler Load;
public event EventHandler? Load;
member this.Load : EventHandler 
Public Custom Event Load As EventHandler

Event Type

EventHandler

Examples

The following code example demonstrates the use of this member. In the example, an event handler reports on the occurrence of the Load 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 type UserControl named UserControl1. Then ensure that the event handler is associated with the Load event.

private void UserControl1_Load(Object sender, EventArgs e) {

   MessageBox.Show("You are in the UserControl.Load event.");
}

Private Sub UserControl1_Load(sender as Object, e as EventArgs) _ 
     Handles UserControl1.Load

   MessageBox.Show("You are in the UserControl.Load event.")

End Sub

Remarks

You can use this event to perform tasks such as allocating resources used by the control.

Note

If the UserControl is part of an MDI child form, the Load event will occur each time the child form is shown. In this case, you should put any one-time initialization code in the UserControl instead of a Load event handler.

Caution

The Load event occurs when the handle for the UserControl is created. In some circumstances, this can cause the Load event to occur more than one time. For example, the Load event occurs when the UserControl is loaded, and again if the handle is recreated. (One way that a handle is recreated is by calling the RecreateHandle method.) To account for the Load event occurring more than one time, you should put any one time initialization code in the UserControl constructor instead of a Load event handler. In addition, you should not add data bindings to the UserControl in a Load event handler.

For more information about handling events, see Handling and Raising Events.

Applies to

See also