ViewPager swipe with 2 fingers

问题:

I would to implement a ViewPager swipe with two fingers. I tried to implement a sublcass of ViewPager overriding the onTouchEvent and passing the method to superclass only if the touch is made by 2 fingers. But there is a problem: the swipe animation also works with 1 finger! I think I have to override some other method...

This is my ViewPager class:

public class MyViewPager extends ViewPager{
public MyViewPager(Context context) {
    super(context);
}

public MyViewPager(Context context,AttributeSet attributeSet) {
    super(context,attributeSet);
}

@Override
public boolean onTouchEvent(MotionEvent ev) {
    int n = ev.getPointerCount(); //number of fingers
    if (n == 2)
        return super.onTouchEvent(ev);
    else return false;
}
}

回答1:

Overriding onInterceptTouchEvent() should do the trick. According to the comments in the ViewPager sources, it's there where the decision is made whether scrolling should start or not.

回答2:

im writing this code and its working for two finger .

boolean freeTwo = false;

@Override
public boolean onTouchEvent(MotionEvent ev) {

    final int action = ev.getAction() & MotionEventCompat.ACTION_MASK;
    int counter = ev.getPointerCount() ;

    if(counter == 1 && (action== MotionEvent.ACTION_DOWN || action== MotionEvent.ACTION_MOVE) && !freeTwo)
    {
        if(action == MotionEvent.ACTION_MOVE)
            freeTwo = true;
        return super.onTouchEvent(ev);
    }

    if(counter == 2 && (action== MotionEvent.ACTION_POINTER_DOWN|| action== MotionEvent.ACTION_MOVE || action== MotionEvent.ACTION_POINTER_UP) && freeTwo)
    {
        if(action== MotionEvent.ACTION_POINTER_UP)
            freeTwo = false;
        return super.onTouchEvent(ev);
    }

    ev.setAction(MotionEvent.ACTION_UP);
    return super.onTouchEvent(ev);
}