android 修改viewpager切换速度

public class MyViewPager extends ViewPager {

public MyViewPager(Context context) {
super(context);
init();
}

public MyViewPager(Context context, AttributeSet attrs) {
super(context, attrs);
init();
}
public void init(){
try {
Field mField = ViewPager.class.getDeclaredField("mScroller");
mField.setAccessible(true);
FixedSpeedScroller mScroller = new FixedSpeedScroller(getContext(),new AccelerateInterpolator());
mField.set(this, mScroller);
mScroller.setmDuration(400);
} catch (Exception e) {
e.printStackTrace();
}
}
}

public class FixedSpeedScroller extends Scroller {
private int mDuration = 1500;

public FixedSpeedScroller(Context context) {
super(context);
}

public FixedSpeedScroller(Context context, Interpolator interpolator) {
super(context, interpolator);
}

@Override
public void startScroll(int startX, int startY, int dx, int dy, int duration) {
// Ignore received duration, use fixed one instead
super.startScroll(startX, startY, dx, dy, mDuration);
}

@Override
public void startScroll(int startX, int startY, int dx, int dy) {
// Ignore received duration, use fixed one instead
super.startScroll(startX, startY, dx, dy, mDuration);
}

public void setmDuration(int time) {
mDuration = time;
}

public int getmDuration() {
return mDuration;
}
}