首先明確指出的是你要解決的問題沒有可行的解決方案，然後你還有興趣的話，可以繼續往下看。

繼續往下看的程式設計師都是好程式設計師！！！

本人開發環境：VS2013 && .NET 4.5.1

問題：在wpf中嵌入WindowsFormsHost後，WINFORM的元素都在最頂層，所以要在TABCONTROL中切來切去的時候，會發現不管咋切winform的元素都處於顯示狀態，就算當你想用SCROLLVIEWER包一下，對不起，當你使用滾動條的時候，winform元素甚至連你的滾動條都 遮擋了。

對於此問題，無解！無解！無解！

首先看一下MS的說法：

According to
 
 MSDN (Layout Considerations for the WindowsFormsHost Element)


A hosted Windows Forms control is drawn in a separate HWND, so it is always drawn on top of WPF elements.

This is a design limitation

意思就是說，WINFORM元素一直都在最頂層，這是設計的限制。
一直到.NET FRAMEWORK 4.0時候都是這個狀況。

再看看MS對這個問題的嘗試

A year later, things have changed a bit with
 
 .NET 4.5. For those who stumbled upon this, much as I did, here is a more updated excerpt from Walkthrough: Arranging Windows Forms Controls in WPF on MSDN:


By default, visible WindowsFormsHost elements are always drawn on top of other WPF elements, and they are unaffected by z-order. To enable z-ordering, set
 
 the IsRedirected property of the WindowsFormsHost to true and the CompositionMode property to Full or OutputOnly.

All you need to do, when using .NET 4.5, is add the following attributes to your WindowsFormsHost element IsRedirected="True" and CompositionMode="Full" or CompositionMode="OutputOnly".

在.net 4.5，微軟嘗試解決這個問題，就是新增幾個屬性的事。這是個大坑，也不知道到底解決的如何，此功能僅限於4.5 BETA版，在正式版裡，又沒有這兩個屬性了。
（微軟自己都解決不了的問題，真尷尬！！！）

再看看MS的新說法

1.3.10 Windows Presentation Foundation (WPF) 1.3.10.1 HwndHost feature has been removed from WPF in the .NET Framework 4.5 Beta The .NET Framework 4.5 Developer Preview included a WPF HwndHost redirection feature. However, this feature had several known issues and has been removed from the .NET Framework 4.5 Beta. It will not be included in any future releases. To resolve this issue: No workaround is available.

意思是說：
1.3.10WindowsPresentationFoundation(WPF)1.3.10.1HwndHost特性已被刪除從WPF。淨框架4.5Beta。淨框架4.5開發人員預覽版包括一個WPFHwndHost重定向功能。然而,這個功能有幾個已知問題和已被刪除。淨框架4.5Beta。它將不會被包括在任何未來的版本。解決這一問題:沒有可用的解決方法。

總之就是無解，無解，無解！！！

以下是一些連結，也是說的相同問題