private void _scrollViewer_DirectManipulationCompleted(object sender, object e)
{
_timer.Stop();
if (ListViewRequestDataContext.IsPullDownRefreshStatus && this.IsShowPullDownRefresh && null != PullDownRefresh)
{
PullDownRefresh.Invoke(this, null);
//执行刷新操作
}
ListViewRequestDataContext.IsPullDownRefreshStatus = false;
//Debug.WriteLine("_scrollViewer_DirectManipulationCompleted");
}
private void _scrollViewer_ViewChanged(object sender, ScrollViewerViewChangedEventArgs e)
{
//在 pc 上 //TODO:在能够区分 desktop and phone 的时候添加对pc端下拉刷新的支持
if (null != PullDownRefresh && !_isHasDirectManipulationStarted && !ListViewRequestDataContext.IsPullDownRefreshStatus && !ListViewRequestDataContext.IsPullUpLoadMoreStatus)
{
var timeNow = DateTime.Now;
//Debug.WriteLine("start:" + " Height=" + ScrollViewer.Height + " ActualHeight=" + ScrollViewer.ActualHeight + " ScrollableHeight=" + ScrollViewer.ScrollableHeight + " ExtentHeight=" + ScrollViewer.ExtentHeight + " VerticalOffset=" + ScrollViewer.VerticalOffset);
if ((timeNow - _pullScrllTime).TotalSeconds < 0.3) //连续操作中
{
//如果已经触发 且时间小于1.5秒内 则不操作
if (ListViewRequestDataContext.IsPullDownRefreshStatus && ((timeNow - _startedTime).TotalSeconds < 1.5))
{
return;
}
if (_startedOffset == -1) //第一次 update
{
_startedOffset = (int)ScrollViewer.VerticalOffset;
//Debug.WriteLine("_scrollViewer_ViewChanged 第一次 update " + " ScrollViewer.VerticalOffset=" + ScrollViewer.VerticalOffset);
}
else if (ScrollViewer.VerticalOffset < 0.5 && _startedOffset != 0) //满足置顶 条件 执行刷新 //这里发现手动滑动 有时候Voffset未必刚好为0 所以暂时做0.5的容错
{
//Debug.WriteLine("_scrollViewer_ViewChanged 满足置顶 条件 执行刷新update " + " ScrollViewer.VerticalOffset=" + ScrollViewer.VerticalOffset);
_startedOffset = -1;
_startedTime = timeNow;
ListViewRequestDataContext.IsPullDownRefreshStatus = true;
PullDownRefresh.Invoke(this, null);
}
}
else //非连续操作 重置数据
{
//Debug.WriteLine("_scrollViewer_ViewChanged 非连续操作 重置数据 " + " ScrollViewer.VerticalOffset=" + ScrollViewer.VerticalOffset);
_startedOffset = -1;
_startedTime = timeNow;
}
_pullScrllTime = timeNow;
}
// Debug.WriteLine("end:" + " Height=" + ScrollViewer.Height + " ActualHeight=" + ScrollViewer.ActualHeight + " ScrollableHeight=" + ScrollViewer.ScrollableHeight + " ExtentHeight=" + ScrollViewer.ExtentHeight + " VerticalOffset=" + ScrollViewer.VerticalOffset);
}
