Control.PointToClient メソッド

[アーティクル]
03/28/2008

指定した画面上のポイントを計算してクライアント座標を算出します。

Public Function PointToClient( _
   ByVal p As Point _) As Point
[C#]
public Point PointToClient(Pointp);
[C++]
public: Point PointToClient(Pointp);
[JScript]
public function PointToClient(
   p : Point) : Point;

パラメータ

p
画面座標で示された変換対象の Point 。

戻り値

変換された Point 、 p をクライアント座標で表す Point 。

使用例

[Visual Basic, C#, C++] ユーザーがイメージまたはイメージファイルをフォームにドラッグできるようにし、ドロップされた場所にそのイメージを表示する例を次に示します。 OnPaint メソッドは、フォームが描画されるたびにイメージを再描画するためオーバーライドされます。されない場合、イメージは次回の再描画までそのままの状態で残ります。 DragEnter イベント処理メソッドでは、フォームにドラッグされているデータの種類を判別し、適切なフィードバックを提供します。 DragDrop イベント処理メソッドでは、 Image をデータから作成できる場合に、フォーム上にイメージを表示します。 DragEventArgs.X および DragEventArgs.Y の値は画面座標であるため、この例では PointToClient メソッドを使用して値をクライアント座標に変換しています。

 
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 Not (Me.picture Is 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

[C#] 
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;
   }
}

[C++] 
private:
   Image*  picture;
   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::Form1_DragDrop);
      this->DragEnter += new DragEventHandler(this, &Form1::Form1_DragEnter);
   }

protected:
   void OnPaint(PaintEventArgs* e) {
      // If there is an image and it has a location,
      // paint it when the Form is repainted.
      Form::OnPaint(e);
      if (this->picture != 0 && 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( 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;
         }
   }

[JScript] JScript のサンプルはありません。Visual Basic、C#、および C++ のサンプルを表示するには、このページの左上隅にある言語のフィルタボタンをクリックします。

必要条件

プラットフォーム: Windows 98, Windows NT 4.0, Windows Millennium Edition, Windows 2000, Windows XP Home Edition, Windows XP Professional, Windows Server 2003 ファミリ, .NET Compact Framework - Windows CE .NET

参照

Control クラス | Control メンバ | System.Windows.Forms 名前空間 | Point | PointToScreen

次の方法で共有

Control.PointToClient メソッド

パラメータ

戻り値

使用例

必要条件

参照

その他のリソース