Windows如何决定是否显示UAC提示？

Installer Detection only applies to:

1. 32 bit executables
2. Applications without a requestedExecutionLevel
3. Interactive processes running as a Standard User with LUA enabled

Before a 32 bit process is created,the following attributes are checked to determine whether it is an installer:

• Filename includes keywords like “install,” “setup,” “update,” etc.
• Keywords in the following Versioning Resource fields: Vendor,Company Name,Product Name,File Description,Original Filename,Internal Name,and Export Name.
• Keywords in the side-by-side manifest embedded in the executable.
• Keywords in specific StringTable entries linked in the executable.
• Key attributes in the RC data linked in the executable.
• Targeted sequences of bytes within the executable.

所以,正如你所说：

but i have a exe which checks for updates to software

我的猜测是这个CheckForUpdates.exe是触发兼容性启发式.

正确的做法是将“检查”可执行文件的汇编清单通知Windows,它不应该提升实用程序.这是通过清单中的asInvoker的requestedExecutionLevel完成的：

AssemblyManifest.xml：

<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<assembly xmlns="urn:schemas-microsoft-com:asm.v1" manifestVersion="1.0"> 
   <assemblyIdentity 
      version="1.0.0.0"
      processorArchitecture="X86"
      name="client"
      type="win32"
   /> 

   <description>Update checker</description> 

   <!-- Run as standard user. Disable file and registry virtualization -->
   <trustInfo xmlns="urn:schemas-microsoft-com:asm.v2">
      <security>
         <requestedPrivileges>
            <requestedExecutionLevel level="asInvoker" uiAccess="false"/>
         </requestedPrivileges>
      </security>
   </trustInfo>
</assembly>

这样,您的“检查更新”应用程序将永远不会升高,也不会错误地获得管理员权限.

如果您希望更新程序实际应用更新(需要管理权限的更新),那么您将以管理员身份启动更新程序.

示例代码

//Check if there are updates available
if (!CheckForUpdatesAvailable())
   return; //no updates. We're done

//If the user is an administrator,then get the update
if (IsUserAnAdmin())
{
    //Maybe throw in a "Hey,user,wanna get the update now?" dialog
    DownloadAndApplyUpdates();
    return;
}

//The user is not an admin. 
//Relaunch ourselves as administrator so we can download the update
//Maybe throw in a "Hey,wanna get the update now?" dialog. A button with a UAC shield on it
ExecuteAsAdmin(Application.ExecutablePath,"/downloadUpdate");

与助手功能：

private Boolean IsUserAnAdmin()
{
    //A user can be a member of the Administrator group,but not an administrator.
    //Conversely,the user can be an administrator and not a member of the administrators group.
    var identity = WindowsIdentity.GetCurrent();
    return (null != identity && new WindowsPrincipal(identity).IsInRole(WindowsBuiltInRole.Administrator));
}

private void ExecuteAsAdmin(string Filename,string Arguments)
{
    ProcessStartInfo startInfo = new ProcessStartInfo(Filename,Arguments);
    startInfo.Verb = "runas";
    System.Diagnostics.Process.Start(startInfo);
}

然后,您只需要在启动时查找/ downloadUpdate命令行参数即可知道您的工作是实际工作：

public Form1()
{
    InitializeComponent();

    //Ideally this would be in program.cs,before the call to Application.Run()
    //But that would require me to refactor code out of the Form file,which is overkill for a demo
    if (FindCmdLineSwitch("downloadUpdate",true))
    {
        DownloadAndApplyUpdates();
        Environment.Exit(0);
    }
}

Note: Any code is released into the public domain. No attribution required.