Form.Activate 方法

定义

命名空间:

System.Windows.Forms

程序集:

System.Windows.Forms.dll

激活窗体并给予它焦点。

public:
 void Activate();

public void Activate ();

member this.Activate : unit -> unit

Public Sub Activate ()

示例

以下示例演示如何使用 SetDesktopLocation、 Load 和 Activate 成员。 若要运行该示例，请将以下代码粘贴到名为 的Form1窗体中，其中包含一个名为 的Button1按钮和两Label个名为 和 Label2的Label1控件。

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;
}

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;
}

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

注解

如果这是活动应用程序，则激活窗体会将其置于前面;如果这不是活动应用程序，则激活窗体会闪烁窗口描述文字。 窗体必须可见，此方法才能产生任何效果。 若要确定应用程序中的活动窗体， ActiveForm 请使用 属性或 ActiveMdiChild 属性（如果窗体位于多文档接口 (MDI) 应用程序）。

另请参阅

• ActiveForm
• ActiveMdiChild