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PaintEventArgs-Klasse

Stellt Daten für das Paint-Ereignis bereit.

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

public class PaintEventArgs : EventArgs, IDisposable
public class PaintEventArgs extends EventArgs implements IDisposable
public class PaintEventArgs extends EventArgs implements IDisposable

Das Paint-Ereignis tritt ein, wenn ein Steuerelement neu gezeichnet wird. PaintEventArgs gibt die zum Zeichnen des Steuerelements verwendete Graphics und das ClipRectangle an, in dem gezeichnet werden soll.

Informationen über das Ereignismodell finden Sie unter Ereignisse und Delegaten.

Im folgenden Beispiel wird veranschaulicht, wie das Paint-Ereignis behandelt und die PaintEventArgs-Klasse verwendet wird, um im Formular Rechtecke zu zeichnen. Das MouseDown-Ereignis und das MouseUp-Ereignis werden behandelt, um die Größe des Rechtecks zu bestimmen. Das Beispiel veranschaulicht auch, wie mithilfe der Invalidate-Methode der Bereich des Rechtecks für ungültig erklärt und dadurch das Neuzeichnen erzwungen wird.


private Rectangle RcDraw;
private float PenWidth = 5;

private void Form1_MouseDown(object sender, System.Windows.Forms.MouseEventArgs e)
{

    // Determine the initial rectangle coordinates...

    RcDraw.X = e.X;
    RcDraw.Y = e.Y;

}

private void Form1_MouseUp(object sender, System.Windows.Forms.MouseEventArgs e)
{

    // Determine the width and height of the rectangle...

    if(e.X < RcDraw.X)
    {
        RcDraw.Width = RcDraw.X - e.X;
        RcDraw.X = e.X;
    }
    else
    {
        RcDraw.Width = e.X - RcDraw.X;
    }

    if(e.Y < RcDraw.Y)
    {
        RcDraw.Height = RcDraw.Y - e.Y;
        RcDraw.Y = e.Y;
    }
    else
    {
        RcDraw.Height = e.Y - RcDraw.Y;
    }

    // Force a repaint of the region occupied by the rectangle...

    this.Invalidate(RcDraw);

}

private void Form1_Paint(object sender, System.Windows.Forms.PaintEventArgs e)
{

    // Draw the rectangle...

    e.Graphics.DrawRectangle(new Pen(Color.Blue, PenWidth), RcDraw);
    
}


private Rectangle rcDraw;

private float penWidth = 5;

private void Form1_MouseDown(Object sender,
    System.Windows.Forms.MouseEventArgs e)
{
    // Determine the initial rectangle coordinates...
    rcDraw.set_X(e.get_X());
    rcDraw.set_Y(e.get_Y());
} //Form1_MouseDown

private void Form1_MouseUp(Object sender, 
    System.Windows.Forms.MouseEventArgs e)
{
    // Determine the width and height of the rectangle...
    if (e.get_X() < rcDraw.get_X()) {
        rcDraw.set_Width(rcDraw.get_X() - e.get_X());
        rcDraw.set_X(e.get_X());
    }
    else {
        rcDraw.set_Width(e.get_X() - rcDraw.get_X());
    }

    if (e.get_Y() < rcDraw.get_Y()) {
        rcDraw.set_Height(rcDraw.get_Y() - e.get_Y());
        rcDraw.set_Y(e.get_Y());
    }
    else {
        rcDraw.set_Height(e.get_Y() - rcDraw.get_Y());
    }

    // Force a repaint of the region occupied by the rectangle...
    this.Invalidate(rcDraw);
} //Form1_MouseUp

private void Form1_Paint(Object sender,
    System.Windows.Forms.PaintEventArgs e)
{
    // Draw the rectangle...
    e.get_Graphics().DrawRectangle(new Pen(Color.get_Blue(), 
        penWidth), rcDraw);
} //Form1_Paint

// This example creates a PictureBox control on the form and draws to it.
// This example assumes that the Form_Load event handler method is
// connected to the Load event of the form.

private PictureBox pictureBox1 = new PictureBox();
private void Form1_Load(object sender, System.EventArgs e)
{
    // Dock the PictureBox to the form and set its background to white.
    pictureBox1.Dock = DockStyle.Fill;
    pictureBox1.BackColor = Color.White;
    // Connect the Paint event of the PictureBox to the event handler method.
    pictureBox1.Paint += new System.Windows.Forms.PaintEventHandler(this.pictureBox1_Paint);

    // Add the PictureBox control to the Form.
    this.Controls.Add(pictureBox1);
}

private void pictureBox1_Paint(object sender, System.Windows.Forms.PaintEventArgs e)
{
    // Create a local version of the graphics object for the PictureBox.
    Graphics g = e.Graphics;

    // Draw a string on the PictureBox.
    g.DrawString("This is a diagonal line drawn on the control",
        new Font("Arial",10), System.Drawing.Brushes.Blue, new Point(30,30));
    // Draw a line in the PictureBox.
    g.DrawLine(System.Drawing.Pens.Red, pictureBox1.Left, pictureBox1.Top,
        pictureBox1.Right, pictureBox1.Bottom);
}

// This example creates a PictureBox control on the form and draws to it.
// This example assumes that the Form_Load event handler method is
// connected to the Load event of the form.
private PictureBox pictureBox1 = new PictureBox();

private void Form1_Load(Object sender, System.EventArgs e)
{
    // Dock the PictureBox to the form and set its background to white.
    pictureBox1.set_Dock(DockStyle.Fill);
    pictureBox1.set_BackColor(Color.get_White());

    // Connect the Paint event of the PictureBox to the event handler 
    // method.
    pictureBox1.add_Paint(new System.Windows.Forms.PaintEventHandler(this.
        pictureBox1_Paint));

    // Add the PictureBox control to the Form.
    this.get_Controls().Add(pictureBox1);
} //Form1_Load

private void pictureBox1_Paint(Object sender, 
    System.Windows.Forms.PaintEventArgs e)
{
    // Create a local version of the graphics object for the PictureBox.
    Graphics g = e.get_Graphics();

    // Draw a string on the PictureBox.
    g.DrawString("This is a diagonal line drawn on the control", 
        new Font("Arial", 10), System.Drawing.Brushes.get_Blue(), 
        (PointF)new PointF(30, 30));

    // Draw a line in the PictureBox.
    g.DrawLine(System.Drawing.Pens.get_Red(), pictureBox1.get_Left(), 
        pictureBox1.get_Top(), pictureBox1.get_Right(), 
        pictureBox1.get_Bottom());
} //pictureBox1_Paint

Alle öffentlichen statischen (Shared in Visual Basic) Member dieses Typs sind threadsicher. Bei Instanzmembern ist die Threadsicherheit nicht gewährleistet.

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

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Unterstützt in: 2.0, 1.1, 1.0

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Unterstützt in: 2.0, 1.0
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