Gallery在滑动的时候有一个脱手时候的速度，这个速度将会影响Gallery滑动的惯性，有时候我们需要对这个惯性进行处理，这个时候我们就得自己定义View了，自定义个Gallery继承Gallery，并且重写onFling()方法，如下：

public class GalleryDemo extends Gallery {public GalleryDemo(Context context, AttributeSet attrs) {super(context, attrs);// TODO Auto-generated constructor stub}@Overridepublic boolean onFling(MotionEvent e1, MotionEvent e2, float velocityX, float velocityY) {// TODO Auto-generated method stubreturn super.onFling(e1, e2, velocityX / 4, velocityY);}}

值得注意的是自己定义控件的时候得使用 public GalleryDemo(Context context, AttributeSet attrs)构造方法，要不则会出现莫名其妙的异常。

下面就是去使用这个自定义的Gallery了：

public class GalleryDemoActivity extends Activity {private Gallery gl_main;private GalleryAdapter adapter;private int[] pics = new int[] { R.drawable.a1, R.drawable.a2, R.drawable.a3, R.drawable.a4, R.drawable.a5,R.drawable.a6, R.drawable.a7, R.drawable.a8, R.drawable.a9, R.drawable.a10 };/** Called when the activity is first created. */@Overridepublic void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.main);gl_main = (Gallery) findViewById(R.id.gl_main);adapter = new GalleryAdapter();//gl_main.gl_main.setAdapter(adapter);}private class GalleryAdapter extends BaseAdapter {@Overridepublic int getCount() {// TODO Auto-generated method stubreturn pics.length;}@Overridepublic Object getItem(int position) {// TODO Auto-generated method stubreturn null;}@Overridepublic long getItemId(int position) {// TODO Auto-generated method stubreturn position;}@Overridepublic View getView(int position, View convertView, ViewGroup parent) {// TODO Auto-generated method stubImageView iv = new ImageView(GalleryDemoActivity.this);iv.setLayoutParams(new Gallery.LayoutParams(160, 320));iv.setImageResource(pics[position]);return iv;}}
}