Form.Activate Form.Activate Form.Activate Form.Activate Method

定义

激活窗体并给予它焦点。Activates the form and gives it focus.

public:
 void Activate();
public void Activate ();
member this.Activate : unit -> unit
Public Sub Activate ()

示例

下面的代码示例演示如何使用SetDesktopLocationLoadActivate成员。The following code example demonstrates how to use the SetDesktopLocation, Load and Activate members. 若要运行该示例,请将以下代码粘贴在一个称为窗体Form1包含一个按钮调用Button1并将两个Label控件称为Label1Label2To 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.

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

激活窗体将它置于顶层如果这是活动的应用程序,或如果这不是活动的应用程序,它会闪烁窗口标题。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. 该窗体必须可见才能产生任何影响此方法。The form must be visible for this method to have any effect. 若要确定活动窗体应用程序中的,使用ActiveForm属性或ActiveMdiChild属性如果在窗体中的多文档界面 (MDI) 应用程序。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.

安全性

UIPermission
用于更改焦点。for changing focus. 关联枚举:AllWindowsAssociated enumeration: AllWindows.

适用于

另请参阅