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Form.Activate-Methode

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Aktiviert das Formular und übergibt diesem den Fokus.

Namespace: System.Windows.Forms
Assembly: System.Windows.Forms (in system.windows.forms.dll)

Syntax

'Declaration
Public Sub Activate
'Usage
Dim instance As Form

instance.Activate

public void Activate ()

public:
void Activate ()

public void Activate ()

public function Activate ()

Hinweise

Durch Aktivieren eines Formulars wird dieses im Vordergrund angezeigt, wenn es sich um die aktive Anwendung handelt, oder das Symbol in der Taskleiste blinkt, wenn es sich nicht um die aktive Anwendung handelt. Diese Methode wirkt sich nur dann aus, wenn das Formular sichtbar ist. Zum Bestimmen des aktiven Formulars in einer Anwendung verwenden Sie die ActiveForm-Eigenschaft oder die ActiveMdiChild-Eigenschaft, wenn die Formulare Teil einer MDI (Multiple Document Interface)-Anwendung sind.

Beispiel

Im folgenden Codebeispiel wird die Verwendung der Member SetDesktopLocation, Load und Activate veranschaulicht. Zum Ausführen des Beispiels fügen Sie den folgenden Code in ein Formular mit dem Namen Form1 ein, das eine Schaltfläche mit der Bezeichnung Button1 und zwei Label-Steuerelemente mit der Bezeichnung Label1 und Label2 enthält.

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

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;
}

static int x = 200;
static int y = 200;
void Button1_Click( System::Object^ sender, System::EventArgs^ e )
{
   
   // Create a new Form1 and set its Visible property to true.
   Form1^ form2 = gcnew 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.
void Form1_Activated( Object^ sender, System::EventArgs^ e )
{
   Label1->Text = String::Format( "x: {0} y: {1}", x, y );
   Label2->Text = String::Format( "Number of forms currently open: {0}", count );
}

static int count = 0;
void Form1_Closed( Object^ sender, System::EventArgs^ e )
{
   count -= 1;
}

void Form1_Load( Object^ sender, System::EventArgs^ e )
{
   count += 1;
}

private static int x = 200;
private static int y = 200;

private void button1_Click(Object sender, System.EventArgs e)
{
    // Create a new Form1 and set its Visible property to true.
    Form1 form2 = new Form1();
    form2.set_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.set_Enabled(false);
} //button1_Click

// 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.set_Text("x: " + x + " y: " + y);
    label2.set_Text("Number of forms currently open: " + count);
} //Form1_Activated

private static int count = 0;

private void Form1_Closed(Object sender, System.EventArgs e)
{
    count -= 1;
} //Form1_Closed

private void Form1_Load(Object sender, System.EventArgs e)
{
    count += 1;
} //Form1_Load

.NET Framework-Sicherheit

Plattformen

Windows 98, Windows 2000 SP4, Windows CE, Windows Millennium Edition, Windows Mobile für Pocket PC, Windows Mobile für Smartphone, Windows Server 2003, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP SP2, Windows XP Starter Edition

.NET Framework unterstützt nicht alle Versionen sämtlicher Plattformen. Eine Liste der unterstützten Versionen finden Sie unter Systemanforderungen.

Versionsinformationen

.NET Framework

Unterstützt in: 2.0, 1.1, 1.0

.NET Compact Framework

Unterstützt in: 2.0

Siehe auch

Referenz

Form-Klasse
Form-Member
System.Windows.Forms-Namespace
ActiveForm
ActiveMdiChild