Android 解决Gallery下ScrollView滑动事件冲突

在Gallery下，里面内容过长超出屏幕，这时咱们能够用ScrollView来滚动，可是这样作了之后，会发现一个问题，Gallery的滑动事件和ScrollView的滑动事件起冲突，这时咱们能够自定义Gallery控件来避免这个问题：

import android.content.Context;  
import android.util.AttributeSet;  
import android.view.KeyEvent;  
import android.view.MotionEvent;  
import android.widget.Gallery;  
  
public class TestGallery extends Gallery {  
    private float gTouchStartX;  
    private float gTouchStartY;  
  
    public TestGallery(Context context, AttributeSet attrs, int defStyle) {  
        super(context, attrs, defStyle);  
    }  
  
    public TestGallery(Context context, AttributeSet attrs) {  
        super(context, attrs);  
    }  
  
    public TestGallery(Context context) {  
        super(context);  
    }  
      
    @Override  
    public boolean onInterceptTouchEvent(MotionEvent ev) {  
        int action = ev.getAction();  
        switch(action){  
        case MotionEvent.ACTION_DOWN:  
            gTouchStartX = ev.getX();  
            gTouchStartY = ev.getY();  
            super.onTouchEvent(ev);  
            break;  
        case MotionEvent.ACTION_MOVE:  
            final float touchDistancesX = Math.abs(ev.getX()-gTouchStartX);  
            final float touchDistancesY = Math.abs(ev.getY()-gTouchStartY);  
            if(touchDistancesY *2 >= touchDistancesX){  
                return false;  
            }else{  
                return true;  
            }  
        case MotionEvent.ACTION_CANCEL:  
            break;  
        case MotionEvent.ACTION_UP:  
            break;  
        }  
        return false;  
    }  
      
    @Override  
    public boolean onFling(MotionEvent e1, MotionEvent e2, float velocityX,  
            float velocityY) {  
        if(e2.getX() > e1.getX()){  
            onKeyDown(KeyEvent.KEYCODE_DPAD_LEFT, null);  
        }else{  
            onKeyDown(KeyEvent.KEYCODE_DPAD_RIGHT, null);  
        }  
        return false;  
    }  
  
}