Question

我一直在努力平滑我的向上滑动但却无法理解如何完成它。我实际上并不清楚代码的术语/单词作为前面堆栈溢出问题的答案。任何帮助，将不胜感激。请回答代码+解释。感谢提前回复。

我有以下代码向上滑动但不顺畅：

> df
    f v    c
1   a 1 1  a
2  ab 2 2 ab
3 abc 3 3abc

Answer 1

尝试此代码，您可以将速度，最小和最大距离更改为

1）MainSwipe.class

public class MainSwipe extends AppCompatActivity implements SimpleGestureListener{

    private SimpleGestureFilter detector;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.swipe_screen);
        detector = new SimpleGestureFilter(this,this);
    }

    @Override
    public boolean dispatchTouchEvent(MotionEvent me){
        // Call onTouchEvent of SimpleGestureFilter class

        this.detector.onTouchEvent(me);
        return super.dispatchTouchEvent(me);
    }

    @Override
    public void onSwipe(int direction) {

        switch (direction) {
            case SimpleGestureFilter.SWIPE_UP :
                Log.e("UP","UP");
                break;
        }
    }

    @Override
    public void onDoubleTap() {
        Log.e("Doubletab","Doubletab");
    }
}

2）SimpleGestureFilter

public class SimpleGestureFilter extends GestureDetector.SimpleOnGestureListener {

    public final static int SWIPE_UP    = 1;
    public final static int SWIPE_DOWN  = 2;
    public final static int SWIPE_LEFT  = 3;
    public final static int SWIPE_RIGHT = 4;

    public final static int MODE_TRANSPARENT = 0;
    public final static int MODE_SOLID       = 1;
    public final static int MODE_DYNAMIC     = 2;

    private final static int ACTION_FAKE = -13; //just an unlikely number
    private int swipe_Min_Distance = 100;
    private int swipe_Max_Distance = 500;
    private int swipe_Min_Velocity = 100;

    private int mode             = MODE_DYNAMIC;
    private boolean running      = true;
    private boolean tapIndicator = false;

    private Activity context;
    private GestureDetector detector;
    private SimpleGestureListener listener;

    public SimpleGestureFilter(Activity context,SimpleGestureListener sgl) {

        this.context = context;
        this.detector = new GestureDetector(context, this);
        this.listener = sgl;
    }

    public void onTouchEvent(MotionEvent event){

        if(!this.running)
            return;

        boolean result = this.detector.onTouchEvent(event);

        if(this.mode == MODE_SOLID)
            event.setAction(MotionEvent.ACTION_CANCEL);
        else if (this.mode == MODE_DYNAMIC) {

            if(event.getAction() == ACTION_FAKE)
                event.setAction(MotionEvent.ACTION_UP);
            else if (result)
                event.setAction(MotionEvent.ACTION_CANCEL);
            else if(this.tapIndicator){
                event.setAction(MotionEvent.ACTION_DOWN);
                this.tapIndicator = false;
            }

        }
        //else just do nothing, it's Transparent
    }

    public void setMode(int m){
        this.mode = m;
    }

    public int getMode(){
        return this.mode;
    }

    public void setEnabled(boolean status){
        this.running = status;
    }

    public void setSwipeMaxDistance(int distance){
        this.swipe_Max_Distance = distance;
    }

    public void setSwipeMinDistance(int distance){
        this.swipe_Min_Distance = distance;
    }

    public void setSwipeMinVelocity(int distance){
        this.swipe_Min_Velocity = distance;
    }

    public int getSwipeMaxDistance(){
        return this.swipe_Max_Distance;
    }

    public int getSwipeMinDistance(){
        return this.swipe_Min_Distance;
    }

    public int getSwipeMinVelocity(){
        return this.swipe_Min_Velocity;
    }

    @Override
    public boolean onFling(MotionEvent e1, MotionEvent e2, float velocityX,
                           float velocityY) {

        final float xDistance = Math.abs(e1.getX() - e2.getX());
        final float yDistance = Math.abs(e1.getY() - e2.getY());

        if(xDistance > this.swipe_Max_Distance || yDistance > this.swipe_Max_Distance)
            return false;

        velocityX = Math.abs(velocityX);
        velocityY = Math.abs(velocityY);
        boolean result = false;

        if(velocityX > this.swipe_Min_Velocity && xDistance > this.swipe_Min_Distance){
            if(e1.getX() > e2.getX()) // right to left
                this.listener.onSwipe(SWIPE_LEFT);
            else
                this.listener.onSwipe(SWIPE_RIGHT);

            result = true;
        }
        else if(velocityY > this.swipe_Min_Velocity && yDistance > this.swipe_Min_Distance){
            if(e1.getY() > e2.getY()) // bottom to up
                this.listener.onSwipe(SWIPE_UP);
            else
                this.listener.onSwipe(SWIPE_DOWN);

            result = true;
        }

        return result;
    }

    @Override
    public boolean onSingleTapUp(MotionEvent e) {
        this.tapIndicator = true;
        return false;
    }

    @Override
    public boolean onDoubleTap(MotionEvent arg) {
        this.listener.onDoubleTap();;
        return true;
    }

    @Override
    public boolean onDoubleTapEvent(MotionEvent arg) {
        return true;
    }

    @Override
    public boolean onSingleTapConfirmed(MotionEvent arg) {

        if(this.mode == MODE_DYNAMIC){        // we owe an ACTION_UP, so we fake an
            arg.setAction(ACTION_FAKE);      //action which will be converted to an ACTION_UP later.
            this.context.dispatchTouchEvent(arg);
        }

        return false;
    }
}

3）接口SimpleGestureListener

public interface SimpleGestureListener {
    void onSwipe(int direction);
    void onDoubleTap();
}

我怎样才能使向上滑动的方向变得平滑？

1 个答案: