实现Fragment的切换和ViewPager自动循环设置切换时间

    Field mScroller;
            mScroller = ViewPager.class.getDeclaredField("mScroller");
            mScroller.setAccessible(true);
            FixedSpeedScroller scroller = new FixedSpeedScroller(advPager.getContext(), new LinearInterpolator());
            scroller.setmDuration(500);
            mScroller.set(advPager, scroller);

public class FixedSpeedScroller extends Scroller {

    private int mDuration = 5000;

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

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

    @TargetApi(Build.VERSION_CODES.HONEYCOMB)
    public FixedSpeedScroller(Context context, Interpolator interpolator, boolean flywheel) {
        super(context, interpolator, flywheel);
    }


    @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 mDuration) {
        this.mDuration = mDuration;
    }
}