Midlet不是抽象的，不会覆盖抽象方法

Question

每当我尝试实施CommandListener时，我都会收到以下消息。请让我知道我需要做什么？

  

Midlet不是抽象的，不会覆盖抽象方法   CommandListener中的commandAction（Command，Displayable）

package displaytest;
import javax.microedition.lcdui.Display;
import javax.microedition.lcdui.Form;
import javax.microedition.midlet.MIDlet;
import javax.microedition.lcdui.*;


public class Midlet extends MIDlet  implements CommandListener {

  private Display display = null;
  private Form form;

  public void startApp() {
    form = new Form("Hello World");
    String msg = "Hello World!  DisplayTest 12";
    form.addCommand(screen);
    form.addCommand(ok);
    form.append(msg);
    display = Display.getDisplay(this);
    display.setCurrent(form);
  }

  private Command screen, ok;

  public Midlet(){
    form = new Form("Command Form");
    screen = new Command("SCREEN", Command.SCREEN, 1);
    ok = new Command("OK", Command.OK, 4);
  }

  public void pauseApp() {

  }

  public void destroyApp(boolean unconditional) {
    notifyDestroyed();
  }

  public void okCom(){
    Alert ok = new Alert("OK Command", "OK Command Executed!", null, AlertType.INFO);
    ok.setTimeout(5000);
    display.setCurrent(ok, form);  
  }

}

Answer 1

您需要实现接口声明的方法，检查CommandListener您需要实现它声明的方法如下

void commandAction(Command c, Displayable d){
 // your logic
} 

Answer 2

您需要使类成为抽象，或覆盖抽象方法commandAction(Command,Displayable)。