Occurs when the form is activated in code or by the user.
Assembly: System.Windows.Forms (in System.Windows.Forms.dll)
When the application is active and has multiple forms, the active form is the form with the input focus. A form that is not visible cannot be the active form. The simplest way to activate a visible form is to click it or use an appropriate keyboard combination.
To activate a form at run time using code, call the Activate method. You can use this event for tasks such as updating the contents of the form based on changes made to the form's data when the form was not activated.
For more information about handling events, see Consuming Events.
The following code example demonstrates how to use the SetDesktopLocation, Closed, Load, , and Activate members. To run the example, paste the following code in a form called Form1 containing a Button called Button1 and two Label controls called Label1 and Label2.
Shared x As Integer = 200 Shared y As Integer = 200 Private Sub Button1_Click(ByVal sender As System.Object, _ ByVal e As System.EventArgs) Handles Button1.Click ' Create a new Form1 and set its Visible property to true. Dim form2 As New Form1 form2.Visible = True ' Set the new form's desktop location so it appears below and ' to the right of the current form. form2.SetDesktopLocation(x, y) x += 30 y += 30 ' Keep the current form active by calling the Activate method. Me.Activate() Me.Button1.Enabled = False End Sub ' Updates the label text to reflect the current values of x and y, ' which was were incremented in the Button1 control's click event. Private Sub Form1_Activated(ByVal sender As Object, _ ByVal e As System.EventArgs) Handles MyBase.Activated Label1.Text = "x: " & x & " y: " & y Label2.Text = "Number of forms currently open: " & count End Sub Shared count As Integer = 0 Private Sub Form1_Closed(ByVal sender As Object, _ ByVal e As System.EventArgs) Handles MyBase.Closed count -= 1 End Sub Private Sub Form1_Load(ByVal sender As Object, _ ByVal e As System.EventArgs) Handles MyBase.Load count += 1 End Sub