.net - 为什么 ListBoxItem.OnCreateAutomationPeer() 返回 ListBoxItemWrapperAutomationPeer？

Question

在 .NET Framework 4.7.1 中，ListBoxItem.OnCreateAutomationPeer()返回一个 ListBoxItemWrapperAutomationPeer。

有人知道为什么它不返回 ListBoxItemAutomationPeer 吗？它会更有用，因为 ListBoxItemWrapperAutomationPeer 不做任何事情，但 ListBoxItemPeer 允许选择模式。

Answer 1

我刚刚在 AutomationPeer 类的内部注释中找到了答案：

// For ItemsControls, there are typically two different peers for each
// (visible) item:  an "item" peer and a "wrapper" peer.  The former
// corresponds to the item itself, the latter to the container.  (These
// are different peers, even when the item is its own container.)  The item
// peer appears as a child of the ItemsControl's peer, while the wrapper
// peer is what you get by asking the container for its peer directly.
// For example, a ListBoxAutomationPeer holds children of type
// ListBoxItemAutomationPeer, while the peer for a ListBoxItem has type
// ListBoxItemWrapperAutomationPeer.

请参阅https://referencesource.microsoft.com/#PresentationCore/Core/CSharp/System/Windows/Automation/Peers/AutomationPeer.cs,1350