TreeView.Expanding 事件

定义

命名空间:

Microsoft.UI.Xaml.Controls

当树中的节点开始展开时发生。

本文档适用于 Windows 应用 SDK 中 WinUI 的 WinUI 2 for UWP (，请参阅Windows 应用 SDK命名空间) 。

// Register
event_token Expanding(TypedEventHandler<TreeView, TreeViewExpandingEventArgs const&> const& handler) const;

// Revoke with event_token
void Expanding(event_token const* cookie) const;

// Revoke with event_revoker
TreeView::Expanding_revoker Expanding(auto_revoke_t, TypedEventHandler<TreeView, TreeViewExpandingEventArgs const&> const& handler) const;

public event TypedEventHandler<TreeView,TreeViewExpandingEventArgs> Expanding;

Public Custom Event Expanding As TypedEventHandler(Of TreeView, TreeViewExpandingEventArgs) 

事件类型

TypedEventHandler<TreeView,TreeViewExpandingEventArgs>