C#

<br />
public class Graph : System.Windows.Forms.Form  <br />
{<br />
 public Bitmap bt;<br />
 public Graphics myGraphics;	<br />
<br />
   public Graph()<br />
   {<br />
     bt = new Bitmap (800,600);	<br />
     myGraphics = Graphics.FromImage(bt);<br />
   }<br />
<br />
   protected override void OnPaint(PaintEventArgs e)<br />
   {  	<br />
	base.OnPaint(e);<br />
	DrawImage(e.Graphics);<br />
   }<br />
   private void DrawImage(Graphics myGraphics)<br />
   {<br />
    Pen myPen1 = new Pen (color.Blue,1);<br />
		<br />
    Point pt20 = new Point (20,30);<br />
    Point pt21 = new Point (250,30);	<br />
				<br />
    myGraphics.DrawLine (myPen1,pt20,pt21);		<br />
   }<br />
<br />
  public Bitmap ReturnImage() //returns the image back to the bitmap<br />
  {<br />
    DrawImage(myGraphics);<br />
    return bt;<br />
  }<br />
<br />
  private void saveDrawing()<br />
  {<br />
   SaveFileDialog saveFileDialog1 = new SaveFileDialog();<br />
   saveFileDialog1.Title ="Save File";<br />
   saveFileDialog1.Filter = "JPEG Images (*.jpg,*.jpeg)|*.jpg;*.jpeg|Gif Images (*.gif)|*.gif|Bitmaps (*.bmp)|*.bmp";<br />
   <br />
   if(bt != null)<br />
   {<br />
     if ((saveFileDialog1.ShowDialog() == DialogResult.OK))<br />
     {<br />
      string strFileName = saveFileDialog1.FileName;<br />
      bt.Save(strFileName ,ImageFormat.Bmp);<br />
     }<br />
   }<br />
   else<br />
   {<br />
    MessageBox.Show("Blank bitmap");<br />
   }<br />
<br />
 }<br />
<br />
 private void btnSave_Click(object sender, System.EventArgs e)<br />
 {<br />
   saveDrawing();<br />
 }<br />
}<br />
}//end of class<br />

class Graph : Form
{
  protected override void OnPaint(PaintEventArgs e)
  {
    base.OnPaint(e);
    DrawImage(e.Graphics);
  }
 
  private void DrawImage(Graphics g)
  {
    // ...
  }
 
  // The caller should be sure to call Dispose() on the bitmap
  // when finished with it to free memory immediately.
  public Bitmap ReturnImage() // "GetImage" would be a more consistent name
  {
    Bitmap bmp = new Bitmap(Width, Height);
    using (Graphics g = Graphics.FromImage(bmp))
      DrawImage(g);
 
    return bmp;
  }
 
  void SaveDrawing()
  {
    using (SaveFileDialog dialog = new SaveFileDialog())
    {
      // Initialize the dialog...
 
      if (dialog.ShowDialog() == DialogResult.OK)
        using (Bitmap bmp = ReturnImage())
          bmp.Save(dialog.FileName, ImageFormat.Bmp);
    }
  }
 
  // ...
}

<br />
private void DrawSmallRect(Graphics myGraphics)<br />
{<br />
Rectangle myRect1 = new Rectangle (140,200,350,250)<br />
LinearGradientBrush lBrush1 = new LinearGradientBrush( myRect1,<br />
	Color.LightGray,<br />
	Color.White,<br />
	LinearGradientMode.Vertical );<br />
<br />
myGraphics.FillRectangle (lBrush1,myRect1);<br />
}<br />
private void button1_Click(object sender, System.EventArgs e)<br />
{<br />
 temp1 = 1;<br />
}<br />
private void button2_Click(object sender, System.EventArgs e)<br />
{<br />
 temp2 = 1;<br />
}<br />
<br />
protected override void OnPaint(PaintEventArgs e)<br />
{  	<br />
 if(temp1 == 1)<br />
 {<br />
  DrawSmallRect(e.Graphics);<br />
 }<br />
 if(temp2 == 1)<br />
 {<br />
    DrawSmallRect(e.Graphics);<br />
 }<br />
}<br />
i'm trying to draw the same rectangle. i wanna see if it draws onto the same position. Thanks<br />