Form.Activate Method
Activates the form and gives it focus.
[Visual Basic] Public Sub Activate() [C#] public void Activate(); [C++] public: void Activate(); [JScript] public function Activate();
Remarks
Activating a form brings it to the front if this is the active application, or it flashes the window caption if this is not the active application. The form must be visible for this method to have any effect. To determine the active form in an application, use the ActiveForm property or the ActiveMdiChild property if your forms are in a Multiple Document Interface (MDI) application.
Example
[Visual Basic, C#] The following code example demonstrates how to use the SetDesktopLocation, 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. Ensure all events are connected to their event-handling methods.
[Visual Basic] 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 [C#] static int x = 200; static int y = 200; private void Button1_Click(System.Object sender, System.EventArgs e) { // Create a new Form1 and set its Visible property to true. Form1 form2 = 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. this.Activate(); this.Button1.Enabled = false; } // 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 void Form1_Activated(object sender, System.EventArgs e) { Label1.Text = "x: "+x+" y: "+y; Label2.Text = "Number of forms currently open: "+count; } static int count = 0; private void Form1_Closed(object sender, System.EventArgs e) { count -= 1; } private void Form1_Load(object sender, System.EventArgs e) { count += 1; }
[C++, JScript] No example is available for C++ or JScript. To view a Visual Basic or C# example, click the Language Filter button
in the upper-left corner of the page.
Requirements
Platforms: Windows 98, Windows NT 4.0, Windows Millennium Edition, Windows 2000, Windows XP Home Edition, Windows XP Professional, Windows Server 2003 family
.NET Framework Security:
- UIPermission for changing focus. Associated enumeration: UIPermissionWindow.AllWindows.
See Also
Form Class | Form Members | System.Windows.Forms Namespace | ActiveForm | ActiveMdiChild