视图类中的Android onTouchEvent

Question

I've tried debugging with messages and stuff but the only value i get from event.getAction() is 0 ... which i believe is ACTION_DOWN why dont i detect ACTION_MOVE or ACTION_UP??

package com.andrewxd.test01;

import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.Canvas;
import android.graphics.Paint;
import android.view.MotionEvent;
import android.view.View;

public class Game extends View {

    private Bitmap enemy;
    private Enemy enemyN;
    private Paint paint;
    private float x,y;

    public Game(Context context) {
        super(context);
        enemy = BitmapFactory.decodeResource(getResources(), R.drawable.enemy);
        enemy = Bitmap.createScaledBitmap(enemy, 300 , 300, false);
        enemyN = new Enemy(10, 10, enemy);
        paint = new Paint();
        x = 0;
        y = 0;
    }

    @Override
    protected void onDraw(Canvas canvas){
        canvas.drawRect(x, y, 50, 50, paint);
    }


    @Override
    public boolean onTouchEvent(MotionEvent event){
        super.onTouchEvent(event);
        if(event.getAction() == MotionEvent.ACTION_DOWN){
            x = event.getX();
            y = event.getY();
            invalidate();
        } else if(event.getAction() == MotionEvent.ACTION_MOVE){
            x = event.getX();
            y = event.getY();
            invalidate();
        }
        return false;
    }
}

Am I doing something wrong? or is this supposed to work like this? And if this is supposed to be like this where do i detect touch movement

Answer 1

It's because you're returning false at the end of the onTouchEvent. When you return false , you are saying that your View can not handle any more touch events so the events will no longer be sent to the View . If you want to receive MOVE and UP events, then you need to return true.