Creating Images

Question

Im trying to make a double buffered panel.
Ive used the Image x = createImage(intx,inty); method of constructing the image, when i get the graphics to write to the image I always get an execption. the code is as follows
import java.awt.*;
public class BufferedPanel extends Panel {
     Graphics BufferedGraphics ,MainGraphics;
     Image BackBuffer;
     int Xsize, Ysize;
     public BufferedPanel()
          super();
          Xsize = this.getX();
          Ysize = this.getY();
          this.setVisible(true);
          BackBuffer = createImage(Xsize,Ysize);
          System.out.println(BackBuffer);
          //always prints null
          BufferedGraphics = BackBuffer.getGraphics();
          //null pointer execption
          MainGraphics = this.getGraphics();
     private void resetBuffer(){
     Xsize=this.getX();
     Ysize=this.getY();
     // clean up the previous image
     if(BufferedGraphics!=null){
     BufferedGraphics.dispose();
     BufferedGraphics=null;
     if(BackBuffer!=null){
     BackBuffer.flush();
     BackBuffer=null;
     System.gc();
     // create the new image with the size of the panel
     BackBuffer=createImage(Xsize,Ysize);
     BufferedGraphics=BackBuffer.getGraphics();
     public void paint()
          resetBuffer();
          if(BufferedGraphics!=null){
     //this clears the offscreen image, not the onscreen one
     BufferedGraphics.clearRect(0,0,Xsize,Ysize);
     //calls the paintbuffer method with
     //the offscreen graphics as a param
     Draw(BufferedGraphics);
     //we finaly paint the offscreen image onto the onscreen image
     MainGraphics.drawImage(BackBuffer,0,0,this);
     private void Draw(Graphics g){          
thanks for the help

Answer 1

Hello,
make sure your BufferPanel is actually visible "before" your call to createImage().
(T)