ui_low2.java

J2ME 无线通信技术应用开发源代码

// 程序名UI_Low2.java
// 测试repaint方法
import javax.microedition.midlet.*;
import javax.microedition.lcdui.*;
public class UI_Low2 extends MIDlet implements CommandListener{
  private Display  display;
  private MyCanvas canvas;
  private Command cmdExit;
  private Command cmdRepaint;
  boolean isRepaint;
/*
  TextBox textBox;
  Command cmdReturn;
  Command cmdNext;
*/ 
  public UI_Low2(){
    //cmdNext = new Command("Next",Command.SCREEN,1);
    
    isRepaint = false;
    display = Display.getDisplay( this );
    canvas  = new MyCanvas( this );
    cmdExit = new Command("Exit",Command.SCREEN,1);
    cmdRepaint = new Command("Repaint",Command.SCREEN,1);
    canvas.addCommand(cmdExit);
    canvas.addCommand(cmdRepaint);
    
    //canvas.addCommand(cmdNext);
    
    canvas.setCommandListener(this);
/*    
    textBox = new TextBox("tb","tb",50,0);
    cmdReturn = new Command("Return",Command.SCREEN,1);
    textBox.addCommand(cmdReturn);
    textBox.addCommand(cmdRepaint);
    textBox.setCommandListener(this);
*/
  }

  protected void startApp(){
    display.setCurrent( canvas );
  }
   
  protected void pauseApp(){
  }
  
  protected void destroyApp( boolean unconditional ){
  }

  public void commandAction( Command c, Displayable d ){
/*
    if (c == cmdReturn) {
      display.setCurrent(canvas);
      return;
    }
    
    if (c == cmdNext) {
      display.setCurrent(textBox);
      System.out.println("******set screen textBox******");
      return;
    }
*/
    if (c == cmdRepaint) {
      isRepaint = true;
      canvas.repaint(0,0,canvas.getWidth(),canvas.getHeight()/2);
      //canvas.serviceRepaints();
      System.out.println("Method repaint() returned.");
    }
        
    if (c == cmdExit){
      exit();
    }
  }

  public void exit(){
    destroyApp( true );
    notifyDestroyed();
  }
}