android action_up 不工作

Question

我想做的是，当有人将手指向前按住屏幕时等于 true，但当他们将其拿开时等于 false 所以我尝试使用 get_actions() 方法 但只有 action_down 被调用 这是我的代码

public class zombView extends SurfaceView{
    private Bitmap bmp, grass, joystick;
    private SurfaceHolder holder;
    Timer t = new Timer();
    float x = 0, y = 0;
    boolean forward;
    public zombView(Context context) {
          super(context);
          holder = getHolder();
          holder.addCallback(new SurfaceHolder.Callback() {

                 @Override
                 public void surfaceDestroyed(SurfaceHolder holder) {
                 }

                 @Override
                 public void surfaceCreated(final SurfaceHolder holder) {


                     t.scheduleAtFixedRate(new TimerTask(){
                         public void run(){
                        Canvas c = holder.lockCanvas(null);
                        onDraw(c);
                        holder.unlockCanvasAndPost(c);
                        if(forward){
                            x = x + 5;
                        }
                        onTouchEvent(null);
                     }
                 },200,100);
                 }
                 @Override
                 public void surfaceChanged(SurfaceHolder holder, int format,
                               int width, int height) {
                 }
          });
          bmp = BitmapFactory.decodeResource(getResources(), R.drawable.ic_launcher);
          grass = BitmapFactory.decodeResource(getResources(), R.drawable.grassland);
          joystick = BitmapFactory.decodeResource(getResources(), R.drawable.joystic);
    }

    @Override
    protected void onDraw(Canvas canvas) {
          canvas.drawColor(Color.BLACK);
          canvas.drawBitmap(grass, getWidth() - getWidth(), getHeight() - getHeight(), null);
          canvas.drawBitmap(joystick, getWidth() - getWidth(),joystick.getHeight(), null);
          canvas.drawBitmap(bmp, x, y, null);
    }
    @Override
    public boolean onTouchEvent(MotionEvent event) {
        /*switch (event.getAction() & MotionEvent.ACTION_MASK) {
        case MotionEvent.ACTION_DOWN: forward = true;
        case MotionEvent.ACTION_POINTER_DOWN: forward = true;
        case MotionEvent.ACTION_UP: forward = false;
        case MotionEvent.ACTION_POINTER_UP:forward = false;
        case MotionEvent.ACTION_MOVE: forward = true;
        }*/
        if(event.getAction()== MotionEvent.ACTION_DOWN){
            forward = true;
        }if(event.getAction()== MotionEvent.ACTION_UP){
            forward = false;
        }
         return super.onTouchEvent(event);
    }
}

Answer 1

包含此 SurfaceView 的布局未将事件传递到此 SurfaceView。你需要做的是覆盖 ontouch 方法并返回 false 。我希望这会有所帮助。

Answer 2

用这个

          case MotionEvent.ACTION_DOWN:
                    touch_start(x, y);
                    invalidate();
                    break;
                case MotionEvent.ACTION_MOVE:                       
                    touch_move(x, y);
                    invalidate();
                    break;
                case MotionEvent.ACTION_UP:
                    touch_up();
                    invalidate();
                    break;
                }

Answer 3

UI 中的计时器不安全。我可以提出一个我自己的类，目的是保留一些时间和日期，在某些视图中展示它们自己。

import java.text.SimpleDateFormat;
import java.util.ArrayList;
import java.util.Date;
import android.os.Handler;
import android.widget.TextView;
/**
 * The class for creating and refreshing many different fields on different layouts,
 * that can hold actual time and/or date in different formats 
 * The formats should be as in http://developer.android.com/reference/java/text/SimpleDateFormat.html. 
 * Only present and visible fields are being actualized, so there is no need to clean the clock list after closing an activity
 * 
 * Examples of use:
 * 
 *      Clock.registerClock((TextView) findViewById(R.id.TimeField), "HH:mm");
 *      Clock.registerClock((TextView) findViewById(R.id.DateField), "d.M.yyyy EEE");
 *      Clock.start(10000L);
 *
 * @author Petr Gangnus
 */
public final class Clock {
    /**
     * the handler that works instead of timer and supports UI
     */
    static private Handler handler = new Handler();
    /**
     * the interval of the time refreshing
     */
    static private long refreshStep;

    /**
     * pairs TextView timer+time/date format
     */
    private TextView clockFace;
    private String format;
    private Clock(TextView clockFace, String format){
        this.clockFace=clockFace;
        this.format=format;
    }
    // here is the list of views containing the visual timers that should be held actual
    static private ArrayList<Clock> clocks=new ArrayList<Clock>();
    /**
     * fills all timer fields by actual time value, according to their formats.
     */
    static private Runnable mUpdateTimeTask = new Runnable() {
       public void run() {
           for(Clock clock:clocks){
               showActualTimeDate(clock);
           }
           handler.postDelayed(this,refreshStep);
       }
    };

    //============================================ public members ====================================================================
    /**
     * add a clock to the list of updating clocks
     * @param clockFace - the place where the time or date will be shown 
     * @param format - the format of the time/date 
     * @return
     */
    public static boolean registerClock(TextView clockFace, String format){
        if (clockFace==null) return false;
        if(clocks.contains(clockFace)){
            // old clockFace
            clocks.get(clocks.indexOf(clockFace)).format=format;
        } else {
            // new clockFace
            clocks.add(new Clock(clockFace, format));
        }
        return true;
    }
    /**
     * remove a clock from the updating list
     * @param clockFace
     * @return
     */
    public static boolean unRegisterClock(TextView clockFace){
        if (clockFace==null) return false;
        if(clocks.contains(clockFace)){
            // found clockFace
            clocks.remove(clocks.indexOf(clockFace));
        } else {
            // not found clockFace
            return false;
        }
        return true;
    }
    /**
     * put in the "place" the actual date/time in the appropriate "format"
     * @param place
     * @param format
     */
    public static void showActualTimeDate(Clock clock){
        if (clock.clockFace==null) return;
        if (clock.clockFace.getVisibility()!=TextView.VISIBLE) return;
        Date thisDate=new Date();
        SimpleDateFormat df=new SimpleDateFormat(clock.format);
        clock.clockFace.setText(df.format(thisDate));
    }
    /**
     * start the ticking for all clocks
     * @param step the tick interval
     */
    public static void start(long step) { 
        refreshStep=step;
        handler.removeCallbacks(mUpdateTimeTask);
        handler.postDelayed(mUpdateTimeTask, 0);
    }
    /**
     * Stopping ticking all clocks (not removing them)
     * the calling could be put somewhere in onStop
     */
    public static void stop() { 
        handler.removeCallbacks(mUpdateTimeTask);
    }
}