PaintEventArgs Třída

Definice

Obor názvů:

System.Windows.Forms

Sestavení:

System.Windows.Forms.dll

Poskytuje data pro událost Paint.

public ref class PaintEventArgs : EventArgs, IDisposable, System::Drawing::IDeviceContext

public class PaintEventArgs : EventArgs, IDisposable, System.Drawing.IDeviceContext

type PaintEventArgs = class
    inherit EventArgs
    interface IDisposable
    interface IDeviceContext

Public Class PaintEventArgs
Inherits EventArgs
Implements IDeviceContext, IDisposable

Dědičnost

Object

EventArgs

PaintEventArgs

Odvozené

System.Windows.Forms.TableLayoutCellPaintEventArgs

Implementuje

IDisposable IDeviceContext

Příklady

Následující příklad ukazuje zpracování Paint události a použití PaintEventArgs třídy k kreslení obdélníků ve formuláři. Události MouseDown a MouseUp se zpracovávají, aby se určila velikost obdélníku. Příklad také ukazuje metodu Invalidate zneplatnění oblasti obdélníku, což způsobí její překreslení.

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.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);
}

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

   // 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();
// Cache font instead of recreating font objects each time we paint.
private Font fnt = new Font("Arial",10);
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",
        fnt, 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 pictureBox1 As New PictureBox()
Private fnt as New Font("Arial", 10)

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


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", _
        fnt, 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

Poznámky

Událost Paint nastane při překreslení ovládacího prvku. A PaintEventArgs určuje Graphics , který se má použít k malování ovládacího prvku, a pole ClipRectangle , ve kterém se má malovat.

Informace o modelu událostí najdete v tématu Zpracování a vyvolávání událostí.

Konstruktory

PaintEventArgs(Graphics, Rectangle)

Inicializuje novou instanci PaintEventArgs třídy se zadanou grafikou a obdélníkem výřezu.

Vlastnosti

ClipRectangle	Získá obdélník, ve kterém se má malovat.
Graphics	Získá grafiku použitou k malování.

Metody

Dispose()	Uvolní všechny prostředky používané nástrojem PaintEventArgs.
Dispose(Boolean)	Uvolní nespravované prostředky používané PaintEventArgs nástrojem a volitelně uvolní spravované prostředky.
Equals(Object)	Určí, zda se zadaný objekt rovná aktuálnímu objektu. (Zděděno od Object)
Finalize()	Umožňuje objektu pokusit se uvolnit prostředky a provést další operace čištění před jeho uvolněním uvolňováním.
GetHashCode()	Slouží jako výchozí hashovací funkce. (Zděděno od Object)
GetType()	Získá aktuální Type instanci. (Zděděno od Object)
MemberwiseClone()	Vytvoří mělkou kopii aktuálního Objectsouboru . (Zděděno od Object)
ToString()	Vrátí řetězec, který představuje aktuální objekt. (Zděděno od Object)

Explicitní implementace rozhraní

IDeviceContext.GetHdc()	Vrátí popisovač kontextu zařízení s Windows.
IDeviceContext.ReleaseHdc()	Uvolní popisovač kontextu zařízení s Windows.

Viz také

• Graphics
• Rectangle