Control.Invalidate Control.Invalidate Control.Invalidate Control.Invalidate Method

定義

使控制項的特定區域失效,並且造成傳送繪製訊息至控制項。Invalidates a specific region of the control and causes a paint message to be sent to the control.

多載

Invalidate(Region, Boolean) Invalidate(Region, Boolean) Invalidate(Region, Boolean)

使控制項的指定區域失效 (將它加入控制項的更新區域,而這個區域會在下一個繪製作業中重新繪製),並使繪製訊息傳送至控制項。Invalidates the specified region of the control (adds it to the control's update region, which is the area that will be repainted at the next paint operation), and causes a paint message to be sent to the control. 選擇性使指派至控制項的子控制項失效。Optionally, invalidates the child controls assigned to the control.

Invalidate(Rectangle, Boolean) Invalidate(Rectangle, Boolean) Invalidate(Rectangle, Boolean) Invalidate(Rectangle, Boolean)

使控制項的指定區域失效 (將它加入控制項的更新區域,而這個區域會在下一個繪製作業中重新繪製),並使繪製訊息傳送至控制項。Invalidates the specified region of the control (adds it to the control's update region, which is the area that will be repainted at the next paint operation), and causes a paint message to be sent to the control. 選擇性使指派至控制項的子控制項失效。Optionally, invalidates the child controls assigned to the control.

Invalidate(Region) Invalidate(Region) Invalidate(Region)

使控制項的指定區域失效 (將它加入控制項的更新區域,而這個區域會在下一個繪製作業中重新繪製),並使繪製訊息傳送至控制項。Invalidates the specified region of the control (adds it to the control's update region, which is the area that will be repainted at the next paint operation), and causes a paint message to be sent to the control.

Invalidate(Rectangle) Invalidate(Rectangle) Invalidate(Rectangle) Invalidate(Rectangle)

使控制項的指定區域失效 (將它加入控制項的更新區域,而這個區域會在下一個繪製作業中重新繪製),並使繪製訊息傳送至控制項。Invalidates the specified region of the control (adds it to the control's update region, which is the area that will be repainted at the next paint operation), and causes a paint message to be sent to the control.

Invalidate(Boolean) Invalidate(Boolean) Invalidate(Boolean) Invalidate(Boolean)

使控制項的特定區域失效,並且造成傳送繪製訊息至控制項。Invalidates a specific region of the control and causes a paint message to be sent to the control. 選擇性使指派至控制項的子控制項失效。Optionally, invalidates the child controls assigned to the control.

Invalidate() Invalidate() Invalidate() Invalidate()

讓控制項的整個介面失效,並重新繪製控制項。Invalidates the entire surface of the control and causes the control to be redrawn.

Invalidate(Region, Boolean) Invalidate(Region, Boolean) Invalidate(Region, Boolean)

使控制項的指定區域失效 (將它加入控制項的更新區域,而這個區域會在下一個繪製作業中重新繪製),並使繪製訊息傳送至控制項。Invalidates the specified region of the control (adds it to the control's update region, which is the area that will be repainted at the next paint operation), and causes a paint message to be sent to the control. 選擇性使指派至控制項的子控制項失效。Optionally, invalidates the child controls assigned to the control.

public:
 void Invalidate(System::Drawing::Region ^ region, bool invalidateChildren);
public void Invalidate (System.Drawing.Region region, bool invalidateChildren);
member this.Invalidate : System.Drawing.Region * bool -> unit

參數

region
Region Region Region Region

要使其失效的 RegionThe Region to invalidate.

invalidateChildren
Boolean Boolean Boolean Boolean

true 會使控制項的子控制項失效,否則為 falsetrue to invalidate the control's child controls; otherwise, false.

備註

呼叫Invalidate方法不會強制同步小畫家; 若要強制同步小畫家,請呼叫Update方法之後呼叫Invalidate方法。Calling the Invalidate method does not force a synchronous paint; to force a synchronous paint, call the Update method after calling the Invalidate method. 呼叫這個方法時,不含任何參數,會將整個工作區加入到更新區域。When this method is called with no parameters, the entire client area is added to the update region.

另請參閱

Invalidate(Rectangle, Boolean) Invalidate(Rectangle, Boolean) Invalidate(Rectangle, Boolean) Invalidate(Rectangle, Boolean)

使控制項的指定區域失效 (將它加入控制項的更新區域,而這個區域會在下一個繪製作業中重新繪製),並使繪製訊息傳送至控制項。Invalidates the specified region of the control (adds it to the control's update region, which is the area that will be repainted at the next paint operation), and causes a paint message to be sent to the control. 選擇性使指派至控制項的子控制項失效。Optionally, invalidates the child controls assigned to the control.

public:
 void Invalidate(System::Drawing::Rectangle rc, bool invalidateChildren);
public void Invalidate (System.Drawing.Rectangle rc, bool invalidateChildren);
member this.Invalidate : System.Drawing.Rectangle * bool -> unit
Public Sub Invalidate (rc As Rectangle, invalidateChildren As Boolean)

參數

rc
Rectangle Rectangle Rectangle Rectangle

Rectangle,表示要使其失效的區域。A Rectangle that represents the region to invalidate.

invalidateChildren
Boolean Boolean Boolean Boolean

true 會使控制項的子控制項失效,否則為 falsetrue to invalidate the control's child controls; otherwise, false.

備註

呼叫Invalidate方法不會強制同步小畫家; 若要強制同步小畫家,請呼叫Update方法之後呼叫Invalidate方法。Calling the Invalidate method does not force a synchronous paint; to force a synchronous paint, call the Update method after calling the Invalidate method. 呼叫這個方法時,不含任何參數,會將整個工作區加入到更新區域。When this method is called with no parameters, the entire client area is added to the update region.

另請參閱

Invalidate(Region) Invalidate(Region) Invalidate(Region)

使控制項的指定區域失效 (將它加入控制項的更新區域,而這個區域會在下一個繪製作業中重新繪製),並使繪製訊息傳送至控制項。Invalidates the specified region of the control (adds it to the control's update region, which is the area that will be repainted at the next paint operation), and causes a paint message to be sent to the control.

public:
 void Invalidate(System::Drawing::Region ^ region);
public void Invalidate (System.Drawing.Region region);
member this.Invalidate : System.Drawing.Region -> unit

參數

region
Region Region Region Region

要使其失效的 RegionThe Region to invalidate.

備註

呼叫Invalidate方法不會強制同步小畫家; 若要強制同步小畫家,請呼叫Update方法之後呼叫Invalidate方法。Calling the Invalidate method does not force a synchronous paint; to force a synchronous paint, call the Update method after calling the Invalidate method. 呼叫這個方法時,不含任何參數,會將整個工作區加入到更新區域。When this method is called with no parameters, the entire client area is added to the update region.

另請參閱

Invalidate(Rectangle) Invalidate(Rectangle) Invalidate(Rectangle) Invalidate(Rectangle)

使控制項的指定區域失效 (將它加入控制項的更新區域,而這個區域會在下一個繪製作業中重新繪製),並使繪製訊息傳送至控制項。Invalidates the specified region of the control (adds it to the control's update region, which is the area that will be repainted at the next paint operation), and causes a paint message to be sent to the control.

public:
 void Invalidate(System::Drawing::Rectangle rc);
public void Invalidate (System.Drawing.Rectangle rc);
member this.Invalidate : System.Drawing.Rectangle -> unit
Public Sub Invalidate (rc As Rectangle)

參數

rc
Rectangle Rectangle Rectangle Rectangle

Rectangle,表示要使其失效的區域。A Rectangle that represents the region to invalidate.

備註

呼叫Invalidate方法不會強制同步小畫家; 若要強制同步小畫家,請呼叫Update方法之後呼叫Invalidate方法。Calling the Invalidate method does not force a synchronous paint; to force a synchronous paint, call the Update method after calling the Invalidate method. 呼叫這個方法時,不含任何參數,會將整個工作區加入到更新區域。When this method is called with no parameters, the entire client area is added to the update region.

另請參閱

Invalidate(Boolean) Invalidate(Boolean) Invalidate(Boolean) Invalidate(Boolean)

使控制項的特定區域失效,並且造成傳送繪製訊息至控制項。Invalidates a specific region of the control and causes a paint message to be sent to the control. 選擇性使指派至控制項的子控制項失效。Optionally, invalidates the child controls assigned to the control.

public:
 void Invalidate(bool invalidateChildren);
public void Invalidate (bool invalidateChildren);
member this.Invalidate : bool -> unit
Public Sub Invalidate (invalidateChildren As Boolean)

參數

invalidateChildren
Boolean Boolean Boolean Boolean

true 會使控制項的子控制項失效,否則為 falsetrue to invalidate the control's child controls; otherwise, false.

備註

呼叫Invalidate方法不會強制同步小畫家; 若要強制同步小畫家,請呼叫Update方法之後呼叫Invalidate方法。Calling the Invalidate method does not force a synchronous paint; to force a synchronous paint, call the Update method after calling the Invalidate method. 呼叫這個方法時,不含任何參數,會將整個工作區加入到更新區域。When this method is called with no parameters, the entire client area is added to the update region.

另請參閱

Invalidate() Invalidate() Invalidate() Invalidate()

讓控制項的整個介面失效,並重新繪製控制項。Invalidates the entire surface of the control and causes the control to be redrawn.

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

範例

下列程式碼範例會啟用卸除使用者映像或映像檔拖曳至表單,並讓它顯示在其上的點。The following code example enables the user to drag an image or image file onto the form, and have it be displayed at the point on it is dropped. OnPaint表單繪製每次重新繪製的映像會覆寫方法; 否則為映像就只會保留直到下一步 重新繪製。The OnPaint method is overridden to repaint the image each time the form is painted; otherwise the image would only persist until the next repainting. DragEnter事件處理方法會決定所拖曳至表單的資料類型,並提供適當的回應。The DragEnter event-handling method determines the type of data being dragged into the form and provides the appropriate feedback. DragDrop事件處理方法會顯示在表單中,影像如果Image可以從資料建立。The DragDrop event-handling method displays the image on the form, if an Image can be created from the data. 因為DragEventArgs.XDragEventArgs.Y的值為螢幕座標,此範例會使用PointToClient將它們轉換成工作區座標中的方法。Because the DragEventArgs.X and DragEventArgs.Y values are screen coordinates, the example uses the PointToClient method to convert them to client coordinates.

private:
   Image^ picture;
   Point pictureLocation;

public:
   Form1()
   {
      
      // Enable drag-and-drop operations and
      // add handlers for DragEnter and DragDrop.
      this->AllowDrop = true;
      this->DragDrop += gcnew DragEventHandler( this, &Form1::Form1_DragDrop );
      this->DragEnter += gcnew DragEventHandler( this, &Form1::Form1_DragEnter );
   }

protected:
   virtual void OnPaint( PaintEventArgs^ e ) override
   {
      
      // If there is an image and it has a location,
      // paint it when the Form is repainted.
      Form::OnPaint( e );
      if ( this->picture != nullptr && this->pictureLocation != Point::Empty )
      {
         e->Graphics->DrawImage( this->picture, this->pictureLocation );
      }
   }

private:
   void Form1_DragDrop( Object^ /*sender*/, DragEventArgs^ e )
   {
      
      // Handle FileDrop data.
      if ( e->Data->GetDataPresent( DataFormats::FileDrop ) )
      {
         // Assign the file names to a String* array, in
         // case the user has selected multiple files.
         array<String^>^files = (array<String^>^)e->Data->GetData( DataFormats::FileDrop );
         try
         {
            // Assign the first image to the picture variable.
            this->picture = Image::FromFile( files[ 0 ] );
            
            // Set the picture location equal to the drop point.
            this->pictureLocation = this->PointToClient( Point(e->X,e->Y) );
         }
         catch ( Exception^ ex ) 
         {
            MessageBox::Show( ex->Message );
            return;
         }

      }
      
      // Handle Bitmap data.
      if ( e->Data->GetDataPresent( DataFormats::Bitmap ) )
      {
         try
         {
            // Create an Image and assign it to the picture variable.
            this->picture = dynamic_cast<Image^>(e->Data->GetData( DataFormats::Bitmap ));

            // Set the picture location equal to the drop point.
            this->pictureLocation = this->PointToClient( Point(e->X,e->Y) );
         }
         catch ( Exception^ ex ) 
         {
            MessageBox::Show( ex->Message );
            return;
         }
      }
      
      // Force the form to be redrawn with the image.
      this->Invalidate();
   }

   void Form1_DragEnter( Object^ /*sender*/, DragEventArgs^ e )
   {
      // If the data is a file or a bitmap, display the copy cursor.
      if ( e->Data->GetDataPresent( DataFormats::Bitmap ) || e->Data->GetDataPresent( DataFormats::FileDrop ) )
      {
         e->Effect = DragDropEffects::Copy;
      }
      else
      {
         e->Effect = DragDropEffects::None;
      }
   }
private Image picture;
private Point pictureLocation;

public Form1()
{
   // Enable drag-and-drop operations and 
   // add handlers for DragEnter and DragDrop.
   this.AllowDrop = true;
   this.DragDrop += new DragEventHandler(this.Form1_DragDrop);
   this.DragEnter += new DragEventHandler(this.Form1_DragEnter);
}

protected override void OnPaint(PaintEventArgs e)
{
   // If there is an image and it has a location, 
   // paint it when the Form is repainted.
   base.OnPaint(e);
   if(this.picture != null && this.pictureLocation != Point.Empty)
   {
      e.Graphics.DrawImage(this.picture, this.pictureLocation);
   }
}

private void Form1_DragDrop(object sender, DragEventArgs e)
{
   // Handle FileDrop data.
   if(e.Data.GetDataPresent(DataFormats.FileDrop) )
   {
      // Assign the file names to a string array, in 
      // case the user has selected multiple files.
      string[] files = (string[])e.Data.GetData(DataFormats.FileDrop);
      try
      {
         // Assign the first image to the picture variable.
         this.picture = Image.FromFile(files[0]);
         // Set the picture location equal to the drop point.
         this.pictureLocation = this.PointToClient(new Point(e.X, e.Y) );
      }
      catch(Exception ex)
      {
         MessageBox.Show(ex.Message);
         return;
      }
   }

   // Handle Bitmap data.
   if(e.Data.GetDataPresent(DataFormats.Bitmap) )
   {
      try
      {
         // Create an Image and assign it to the picture variable.
         this.picture = (Image)e.Data.GetData(DataFormats.Bitmap);
         // Set the picture location equal to the drop point.
         this.pictureLocation = this.PointToClient(new Point(e.X, e.Y) );
      }
      catch(Exception ex)
      {
         MessageBox.Show(ex.Message);
         return;
      }
   }
   // Force the form to be redrawn with the image.
   this.Invalidate();
}

private void Form1_DragEnter(object sender, DragEventArgs e)
{
   // If the data is a file or a bitmap, display the copy cursor.
   if (e.Data.GetDataPresent(DataFormats.Bitmap) || 
      e.Data.GetDataPresent(DataFormats.FileDrop) ) 
   {
      e.Effect = DragDropEffects.Copy;
   }
   else
   {
      e.Effect = DragDropEffects.None;
   }
}
Private picture As Image
Private pictureLocation As Point

Public Sub New()
   ' Enable drag-and-drop operations.
   Me.AllowDrop = True
End Sub

Protected Overrides Sub OnPaint(ByVal e As PaintEventArgs)
   MyBase.OnPaint(e)

   ' If there is an image and it has a location, 
   ' paint it when the Form is repainted.
   If (Me.picture IsNot Nothing) And _
     Not (Me.pictureLocation.Equals(Point.Empty)) Then
      e.Graphics.DrawImage(Me.picture, Me.pictureLocation)
   End If
End Sub

Private Sub Form1_DragDrop(ByVal sender As Object, _
  ByVal e As DragEventArgs) Handles MyBase.DragDrop
   ' Handle FileDrop data.
   If e.Data.GetDataPresent(DataFormats.FileDrop) Then
      ' Assign the file names to a string array, in 
      ' case the user has selected multiple files.
      Dim files As String() = CType(e.Data.GetData(DataFormats.FileDrop), String())
      Try
         ' Assign the first image to the 'picture' variable.
         Me.picture = Image.FromFile(files(0))
         ' Set the picture location equal to the drop point.
         Me.pictureLocation = Me.PointToClient(New Point(e.X, e.Y))
      Catch ex As Exception
         MessageBox.Show(ex.Message)
         Return
      End Try
   End If

   ' Handle Bitmap data.
   If e.Data.GetDataPresent(DataFormats.Bitmap) Then
      Try
         ' Create an Image and assign it to the picture variable.
         Me.picture = CType(e.Data.GetData(DataFormats.Bitmap), Image)
         ' Set the picture location equal to the drop point.
         Me.pictureLocation = Me.PointToClient(New Point(e.X, e.Y))
      Catch ex As Exception
         MessageBox.Show(ex.Message)
         Return
      End Try
   End If

   ' Force the form to be redrawn with the image.
   Me.Invalidate()
End Sub

Private Sub Form1_DragEnter(ByVal sender As Object, _
  ByVal e As DragEventArgs) Handles MyBase.DragEnter
   ' If the data is a file or a bitmap, display the copy cursor.
   If e.Data.GetDataPresent(DataFormats.Bitmap) _
      Or e.Data.GetDataPresent(DataFormats.FileDrop) Then
      e.Effect = DragDropEffects.Copy
   Else
      e.Effect = DragDropEffects.None
   End If
End Sub

備註

呼叫Invalidate方法不會強制同步小畫家; 若要強制同步小畫家,請呼叫Update方法之後呼叫Invalidate方法。Calling the Invalidate method does not force a synchronous paint; to force a synchronous paint, call the Update method after calling the Invalidate method. 呼叫這個方法時,不含任何參數,會將整個工作區加入到更新區域。When this method is called with no parameters, the entire client area is added to the update region.

另請參閱

適用於