在Gallery下，里面内容过长超出屏幕，这时我们可以用ScrollView来滚动，但是这样做了以后，会发现一个问题，Gallery的滑动事件和ScrollView的滑动事件起冲突，这时我们可以自定义Gallery控件来避免这个问题：
下面贴出代码：
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);}@Overridepublic 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;}@Overridepublic 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;}}