Question

怎么判断android中ScrollView滑动到了最底部

Answer 1

滚动到顶部判断:
getScrollY() == 0
滚动到底部判断:
View childView = getChildAt(0);
childView.getMeasuredHeight() <= getScrollY() + getHeight();
其中getChildAt表示得到ScrollView的child View
childView.getMeasuredHeight()表示得到子View的高度,
getScrollY()表示得到y轴的滚动距离，
getHeight()为scrollView的高度
getScrollY()达到最大时加上scrollView的高度就的就等于它内容的高度了.
判断滑动位置的地方，可以有两种方式：
1、实现OnTouchListener来监听是否滑动到最底部
OnTouchListener onTouchListener=new OnTouchListener(){
@Override
public boolean onTouch(View v, MotionEvent event) {
switch (event.getAction()) {
case MotionEvent.ACTION_UP:
if (childView != null && childView .getMeasuredHeight()< = getScrollY() + getHeight()) {
} else if (getScrollY() == 0) {
}
break;
}
return false;
}
}
2、重写ScrollView的onScrollChanged的方法，在onScrollChanged函数中判断
public class myScrollView extends ScrollView
{
public myScrollView(Context context)
{
super(context);
}
public myScrollView(Context context, AttributeSet attributeSet)
{
super(context,attributeSet);
}
@Override
protected void onScrollChanged(int l, int t, int oldl, int oldt)
{
View view = (View)getChildAt(getChildCount()-1);
int d = view.getBottom();
d -= (getHeight()+getScrollY());
if(d==0)
{
//you are at the end of the list in scrollview
//do what you wanna do here
}
else
super.onScrollChanged(l,t,oldl,oldt);
}
}