C# WinForm判断Win7下程序是否以管理员身份运行
如果程序不是以管理员身份运行,操作本地文件会提示:System.UnauthorizedAccessException异常。
Vista 和 Windows 7 操作系统为了加强安全,增加了 UAC(用户账户控制) 的机制,如果 UAC 被打开,用户即使是以管理员权限登录,其应用程序默认情况下也无法对系统目录,系统注册表等可能影响系统运行的设置进行写操作。这个机制大大增强了系统的安全性,但对应用程序开发者来说,我们不能强迫用户去关闭UAC,但有时我们开发的应用程序又需要以 Administrator 的方式运行,即 Win7 中 以 as administrator 方式运行,那么我们怎么来实现这样的功能呢?
我们在 win7 下运行一些安装程序时,会发现首先弹出一个对话框,让用户确认是否同意允许这个程序改变你的计算机配置,但我们编写的应用程序默认是不会弹出这个提示的,也无法以管理员权限运行。本文介绍了 C# 程序如何设置来提示用户以管理员权限运行。
首先在项目中增加一个 Application Manifest File
![](https://images.cnblogs.com/cnblogs_com/greatverve/2011122801.png)
默认的配置如下:
<?xml version="1.0" encoding="utf-8"?> <asmv1:assembly manifestVersion="1.0" xmlns="urn:schemas-microsoft-com:asm.v1" xmlns:asmv1="urn:schemas-microsoft-com:asm.v1" xmlns:asmv2="urn:schemas-microsoft-com:asm.v2" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"> <assemblyIdentity version="1.0.0.0" name="MyApplication.app"/> <trustInfo xmlns="urn:schemas-microsoft-com:asm.v2"> <security> <requestedPrivileges xmlns="urn:schemas-microsoft-com:asm.v3"> <!-- UAC Manifest Options If you want to change the Windows User Account Control level replace the requestedExecutionLevel node with one of the following. <requestedExecutionLevel level="asInvoker" uiAccess="false" /> <requestedExecutionLevel level="requireAdministrator" uiAccess="false" /> <requestedExecutionLevel level="highestAvailable" uiAccess="false" /> If you want to utilize File and Registry Virtualization for backward compatibility then delete the requestedExecutionLevel node. --> <requestedExecutionLevel level="asInvoker" uiAccess="false" /> </requestedPrivileges> </security> </trustInfo> </asmv1:assembly>
我们可以看到这个配置中有一个 requestedExecutionLevel 项,这个项用于配置当前应用请求的执行权限级别。这个项有3个值可供选择,如下表所示:
Value | Description | Comment |
asInvoker | The application runs with the same access token as the parent process. | Recommended for standard user applications. Do refractoring with internal elevation points, as per the guidance provided earlier in this document. |
highestAvailable | The application runs with the highest privileges the current user can obtain. | Recommended for mixed-mode applications. Plan to refractor the application in a future release. |
requireAdministrator | The application runs only for administrators and requires that the application be launched with the full access token of an administrator. | Recommended for administrator only applications. Internal elevation points are not needed. The application is already running elevated. |
asInvoker : 如果选这个,应用程序就是以当前的权限运行。
highestAvailable: 这个是以当前用户可以获得的最高权限运行。
requireAdministrator: 这个是仅以系统管理员权限运行。
默认情况下是 asInvoker。
下面是修改后的配置文件:
<?xml version="1.0" encoding="utf-8"?> <asmv1:assembly manifestVersion="1.0" xmlns="urn:schemas-microsoft-com:asm.v1" xmlns:asmv1="urn:schemas-microsoft-com:asm.v1" xmlns:asmv2="urn:schemas-microsoft-com:asm.v2" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"> <assemblyIdentity version="1.0.0.0" name="MyApplication.app"/> <trustInfo xmlns="urn:schemas-microsoft-com:asm.v2"> <security> <requestedPrivileges xmlns="urn:schemas-microsoft-com:asm.v3"> <!-- UAC Manifest Options If you want to change the Windows User Account Control level replace the requestedExecutionLevel node with one of the following. <requestedExecutionLevel level="asInvoker" uiAccess="false" /> <requestedExecutionLevel level="requireAdministrator" uiAccess="false" /> <requestedExecutionLevel level="highestAvailable" uiAccess="false" /> If you want to utilize File and Registry Virtualization for backward compatibility then delete the requestedExecutionLevel node. --> <requestedExecutionLevel level="requireAdministrator" uiAccess="false" /> </requestedPrivileges> </security> </trustInfo> </asmv1:assembly>
配置文件修改后,我们运行应用程序,就会首先弹出这样一个提示框,点 Yes 后,程序才可以继续运行,并且获得系统管理员的权限。
下面再来看看程序如何知道当前运行在系统管理员权限还是非系统管理员权限:
using System.Security.Principal; public static bool IsAdministrator() { WindowsIdentity identity = WindowsIdentity.GetCurrent(); WindowsPrincipal principal = new WindowsPrincipal(identity); return principal.IsInRole(WindowsBuiltInRole.Administrator); }
这段代码可以用于判断当前程序是否运行在系统管理员权限下。如果配置为 asInvoker,在win7 下,这个函数会返回 false ,如果是 requireAdministrator 则返回 true。