http://blogs.microsoft.co.il/blogs/pavely/archive/2012/05/16/windows-8-topmost-vs-topmost.aspx@H_403_2@

特别是评论部分的第二篇文章：@H_403_2@

The topmost window is also affected by the accessibility settings. If you want a window on top of Metro,you need it to declare accessibility. Here are the key points:@H_403_2@

1. The application must demand uiAccess (app.manifest)@H_403_2@ @H_301_22@

2. The application must assert “topmost” window positioning (either in Win32/SetWindowPos or WinForms/WPF’s Topmost property,programmatically or otherwise)@H_403_2@ @H_301_22@

3. Without making changes to the group policy setting,it must be installed to some trusted location [C:\Windows,C:\Program Files,C:\Program Files (x86)].@H_403_2@

   • If you want to be able to run it out of an arbitrary location,you must disable the security setting: “User Account Control: Only elevate UIAccess applications that are installed in secure locations”.@H_403_2@ @H_301_22@

   • This is the same as setting HKLM\Software\Microsoft\Windows\CurrentVersion\Policies\System\ValidateAdminCodeSignatures to 0@H_403_2@ @H_301_22@

   @H_301_22@

4. Said application cannot be run in the debugger@H_403_2@ @H_301_22@

5. If it’s a .NET application:@H_403_2@

   • The manifest must be embedded in a post-build step@H_403_2@ @H_301_22@

   • The application must have “delayed signing” (meaning it cannot be ran from the built-in debugger,although you can build and attach – this is what Microsoft does)@H_403_2@ @H_301_22@

   @H_301_22@

6. The application must be signed with a trusted certificate.@H_403_2@ @H_301_22@

7. Said trusted certificate must be installed to the Trusted Root Certificate Authority (this is important! It must not just simply installed)@H_403_2@ @H_301_22@