我已经扩展了这个HorizontalScrollView
类来实现某种行为。在我里面的 LinearLayout 下,CustomHorizontalScrollView
我只有 2 个子视图(可以说ImageView
)。当用户向一个方向滚动超过 50% 时,我希望我CustomHorizontalScrollView
自动滚动到同一方向的末尾。这就是我实现它的方式:
CustomHorizontalScrollView
类:
public class CustomHorizontalScrollView extends HorizontalScrollView {
private static float downCoordinates = -1;
private static float upCoordinates = -1;
private static int currentPosition = 0;
public CustomHorizontalScrollView(Context ctx) {
super(ctx);
}
public CustomHorizontalScrollView(Context ctx, AttributeSet attrs) {
super(ctx, attrs);
}
@Override
public boolean onTouchEvent(MotionEvent ev) {
if (ev.getAction() == MotionEvent.ACTION_DOWN && downCoordinates == -1) {
downCoordinates = ev.getX();
}
else if (ev.getAction() == MotionEvent.ACTION_UP && upCoordinates == -1) {
upCoordinates = ev.getX();
int scrollViewWidth = this.getMeasuredWidth();
double dist = downCoordinates - upCoordinates;
if (Math.abs(dist) > scrollViewWidth / 2) {
//this.setSmoothScrollingEnabled(true);
// Going forwards
if (dist > 0) {
int max = ((LinearLayout)this.getChildAt(0)).getChildAt(1).getMeasuredWidth();
currentPosition = max;
this.scrollTo(max, 0);
}
// Going backwards
else {
currentPosition = 0;
this.scrollTo(0, 0);
}
}
// reseting the saved Coordinates
downCoordinates = -1;
upCoordinates = -1;
}
return super.onTouchEvent(ev);
}
}
直到这里 - 一切正常。问题是我希望自动滚动顺利完成,所以我尝试使用该smoothScrollTo
函数而不是该scrollTo
函数,但随后没有任何反应(因为没有自动滚动)。我试着声明这个:
this.setSmoothScrollingEnabled(true);
但也没有成功。