判断listview是否滑动到顶部

 

/**

*@returnWhether it is possible for the child view of this layout to

*         scroll up. Override this if the child view is a custom view.

*/

public boolean canChildScrollUp() {

if (android.os.Build.VERSION.SDK_INT < 14) {

if (mTarget instanceof AbsListView) {

final AbsListView absListView = (AbsListView) mTarget;

return absListView.getChildCount() > 0 &&

(absListView.getFirstVisiblePosition() > 0 ||

absListView.getChildAt(0).getTop() < absListView.getPaddingTop());

} else {

return ViewCompat.canScrollVertically(mTarget, -1) || mTarget.getScrollY() > 0;

}

} else {

return ViewCompat.canScrollVertically(mTarget, -1);

}

}