PaintEventArgs 类

为 Paint 事件提供数据。

**命名空间:**System.Windows.Forms
**程序集:**System.Windows.Forms（在 system.windows.forms.dll 中）

语法

声明
Public Class PaintEventArgs
    Inherits EventArgs
    Implements IDisposable
用法
Dim instance As PaintEventArgs

public class PaintEventArgs : EventArgs, IDisposable

public ref class PaintEventArgs : public EventArgs, IDisposable

public class PaintEventArgs extends EventArgs implements IDisposable

public class PaintEventArgs extends EventArgs implements IDisposable

备注

重新绘制控件时发生 Paint 事件。PaintEventArgs 指定绘制控件所用的 Graphics 以及绘制控件所在的 ClipRectangle。

有关事件模型的信息，请参见 事件和委托。

示例

下面的示例说明了如何处理 Paint 事件以及如何使用 PaintEventArgs 类在窗体中绘制矩形。MouseDown 和 MouseUp 事件将被处理以确定矩形的大小。此示例还说明了使矩形区域无效从而对其进行重新绘制的 Invalidate 方法。

Dim RcDraw As Rectangle
Dim PenWidth As Integer = 5


Private Sub Form1_MouseDown(ByVal sender As Object, ByVal e As System.Windows.Forms.MouseEventArgs) Handles MyBase.MouseDown

    ' Determine the initial rectangle coordinates...

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

End Sub

Private Sub Form1_MouseUp(ByVal sender As Object, ByVal e As System.Windows.Forms.MouseEventArgs) Handles MyBase.MouseUp

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

    If e.X < RcDraw.X Then
        RcDraw.Width = RcDraw.X - e.X
        RcDraw.X = e.X
    Else
        RcDraw.Width = e.X - RcDraw.X
    End If

    If e.Y < RcDraw.Y Then
        RcDraw.Height = RcDraw.Y - e.Y
        RcDraw.Y = e.Y
    Else
        RcDraw.Height = e.Y - RcDraw.Y
    End If

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

    Me.Invalidate(RcDraw)

End Sub

Private Sub Form1_Paint(ByVal sender As Object, ByVal e As System.Windows.Forms.PaintEventArgs) Handles MyBase.Paint

    ' Draw the rectangle...

    e.Graphics.DrawRectangle(New Pen(Color.Blue, PenWidth), RcDraw)

End Sub

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;
   void Form1_MouseDown( Object^ /*sender*/, System::Windows::Forms::MouseEventArgs^ e )
   {
      // Determine the initial rectangle coordinates...
      RcDraw.X = e->X;
      RcDraw.Y = e->Y;
   }

   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 );
   }

   void Form1_Paint( Object^ /*sender*/, System::Windows::Forms::PaintEventArgs^ e )
   {
      // Draw the rectangle...
      float PenWidth = 5;
      e->Graphics->DrawRectangle( gcnew 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 pictureBox1 As New PictureBox()

Private Sub Form1_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles MyBase.Load
    ' 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.
    AddHandler pictureBox1.Paint, AddressOf Me.pictureBox1_Paint

    ' Add the PictureBox control to the Form.
    Me.Controls.Add(pictureBox1)
End Sub 'Form1_Load


Private Sub pictureBox1_Paint(ByVal sender As Object, ByVal e As System.Windows.Forms.PaintEventArgs)
    ' Create a local version of the graphics object for the PictureBox.
    Dim g As Graphics = e.Graphics

    ' Draw a string on the PictureBox.
    g.DrawString("This is a diagonal line drawn on the control", _
        New Font("Arial", 10), Brushes.Red, New PointF(30.0F, 30.0F))
    ' Draw a line in the PictureBox.
    g.DrawLine(System.Drawing.Pens.Red, pictureBox1.Left, _ 
        pictureBox1.Top, pictureBox1.Right, pictureBox1.Bottom)
End Sub 'pictureBox1_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;
   void Form1_Load( Object^ /*sender*/, System::EventArgs^ /*e*/ )
   {
      pictureBox1 = gcnew PictureBox;

      // 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 += gcnew System::Windows::Forms::PaintEventHandler( this, &Form1::pictureBox1_Paint );

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

   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",
         gcnew System::Drawing::Font( "Arial",10 ), System::Drawing::Brushes::Blue, 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

继承层次结构

System.Object
   System.EventArgs
    System.Windows.Forms.PaintEventArgs
       System.Windows.Forms.TableLayoutCellPaintEventArgs

线程安全

此类型的任何公共静态（Visual Basic 中的 Shared）成员都是线程安全的，但不保证所有实例成员都是线程安全的。

平台

Windows 98、Windows 2000 SP4、Windows CE、Windows Millennium Edition、Windows Mobile for Pocket PC、Windows Mobile for Smartphone、Windows Server 2003、Windows XP Media Center Edition、Windows XP Professional x64 Edition、Windows XP SP2、Windows XP Starter Edition

.NET Framework 并不是对每个平台的所有版本都提供支持。有关受支持版本的列表，请参见系统要求。

版本信息

.NET Framework

受以下版本支持：2.0、1.1、1.0

.NET Compact Framework

受以下版本支持：2.0、1.0

请参见

参考

PaintEventArgs 成员
System.Windows.Forms 命名空间
Graphics
Rectangle