我有一个包含树视图的scrollviewer.
我以编程方式填充树视图(它没有绑定),并将树视图扩展为预定的treeviewitem.一切正常.
我的问题是,当树扩展时,我想滚动视图,父树视图滚动到我刚刚扩展的树视图.有任何想法吗? – 请记住,树视图每次展开时可能不具有相同的结构,因此排除了仅存储当前滚动位置并重置为…
解决方法:
我遇到了同样的问题,TreeView没有滚动到所选项目.
我做的是,在将树展开到选定的TreeViewItem之后,我调用了Dispatcher Helper方法以允许UI更新,然后在所选项目上使用TransformToAncestor来查找其在ScrollViewer中的位置.这是代码:
// Allow UI Rendering to Refresh
DispatcherHelper.WaitForPriority();
// Scroll to selected Item
TreeViewItem tvi = myTreeView.SelectedItem as TreeViewItem;
Point offset = tvi.TransformToAncestor(myScroll).Transform(new Point(0, 0));
myScroll.ScrollToVerticalOffset(offset.Y);
这是DispatcherHelper代码:
public class DispatcherHelper
{
private static readonly DispatcherOperationCallback exitFrameCallback = ExitFrame;
/// <summary>
/// Processes all UI messages currently in the message queue.
/// </summary>
public static void WaitForPriority()
{
// Create new nested message pump.
DispatcherFrame nestedFrame = new DispatcherFrame();
// Dispatch a callback to the current message queue, when getting called,
// this callback will end the nested message loop.
// The priority of this callback should be lower than that of event message you want to process.
DispatcherOperation exitOperation = Dispatcher.CurrentDispatcher.BeginInvoke(
DispatcherPriority.ApplicationIdle, exitFrameCallback, nestedFrame);
// pump the nested message loop, the nested message loop will immediately
// process the messages left inside the message queue.
Dispatcher.PushFrame(nestedFrame);
// If the "exitFrame" callback is not finished, abort it.
if (exitOperation.Status != DispatcherOperationStatus.Completed)
{
exitOperation.Abort();
}
}
private static Object ExitFrame(Object state)
{
DispatcherFrame frame = state as DispatcherFrame;
// Exit the nested message loop.
frame.Continue = false;
return null;
}
}