Inno Setup 检测已安装的.NET Framework 版本

翻译自：http://kynosarges.org/DotNetVersion.html

由 Jordan Russell 写的 Inno Setup 是一个伟大的安装脚本程序，但缺乏一个内置的函数来确定安装在目标机器上的.NET Framework版本。幸运的是，它很容易使用 Pascal 脚本语言来实现这样的功能。

脚本

在下面的 Inno Setup的 脚本代码块，函数 IsDotNetDetected 检查指定的.NET Framework 版本和至少指定的服务包级别是否被安装了。所有列出的版本字符串是最终的发行版本; 测试版和发布候选通常具有不同的版本号。函数 InitializeSetup 演示了如何使用 IsDotNetDetected 检查 .NET Framework 4.6 是否有服务包。

我把在公共域代码这个小一点，这样你可以将它嵌入到自己的项目，修改和重新发布它，你认为合适。

 [Code]
 function IsDotNetDetected(version: string; service: cardinal): boolean;
 // Indicates whether the specified version and service pack of the .NET Framework is installed.
 //
 // version -- Specify one of these strings for the required .NET Framework version:
 //    'v1.1'          .NET Framework 1.1
 //    'v2.0'          .NET Framework 2.0
 //    'v3.0'          .NET Framework 3.0
 //    'v3.5'          .NET Framework 3.5
 //    'v4\Client'     .NET Framework 4.0 Client Profile
 //    'v4\Full'       .NET Framework 4.0 Full Installation
 //    'v4.5'          .NET Framework 4.5
 //    'v4.5.1'        .NET Framework 4.5.1
 //    'v4.5.2'        .NET Framework 4.5.2
 //    'v4.6'          .NET Framework 4.6
 //    'v4.6.1'        .NET Framework 4.6.1
 //    'v4.6.2'        .NET Framework 4.6.2
 //
 // service -- Specify any non-negative integer for the required service pack level:
 //    0               No service packs required
 //    1, 2, etc.      Service pack 1, 2, etc. required
 var
     key, versionKey: string;
     install, release, serviceCount, versionRelease: cardinal;
     success: boolean;
 begin
     versionKey := version;
     versionRelease := ;

     // .NET 1.1 and 2.0 embed release number in version key
     if version = 'v1.1' then begin
         versionKey := 'v1.1.4322';
     end else if version = 'v2.0' then begin
         versionKey := 'v2.0.50727';
     end

     // .NET 4.5 and newer install as update to .NET 4.0 Full
     else if Pos('v4.', version) =  then begin
         versionKey := 'v4\Full';
         case version of
           'v4.5':   versionRelease := ;
           'v4.5.1': versionRelease := ; // 378758 on Windows 8 and older
           'v4.5.2': versionRelease := ;
           'v4.6':   versionRelease := ; // 393297 on Windows 8.1 and older
           'v4.6.1': versionRelease := ; // 394271 on Windows 8.1 and older
           'v4.6.2': versionRelease := ; // 394806 on Windows 8.1 and older
         end;
     end;

     // installation key group for all .NET versions
     key := 'SOFTWARE\Microsoft\NET Framework Setup\NDP\' + versionKey;

     // .NET 3.0 uses value InstallSuccess in subkey Setup
     if Pos('v3.0', version) =  then begin
         success := RegQueryDWordValue(HKLM, key + '\Setup', 'InstallSuccess', install);
     end else begin
         success := RegQueryDWordValue(HKLM, key, 'Install', install);
     end;

     // .NET 4.0 and newer use value Servicing instead of SP
     if Pos('v4', version) =  then begin
         success := success and RegQueryDWordValue(HKLM, key, 'Servicing', serviceCount);
     end else begin
         success := success and RegQueryDWordValue(HKLM, key, 'SP', serviceCount);
     end;

     // .NET 4.5 and newer use additional value Release
     if versionRelease >  then begin
         success := success and RegQueryDWordValue(HKLM, key, 'Release', release);
         success := success and (release >= versionRelease);
     end;

     result := success and (install = ) and (serviceCount >= service);
 end;

 function InitializeSetup(): Boolean;
 begin
     if not IsDotNetDetected('v4.6', ) then begin
         MsgBox('MyApp requires Microsoft .NET Framework 4.6.'##
             'Please use Windows Update to install this version,'#
             'and then re-run the MyApp setup program.', mbInformation, MB_OK);
         result := false;
     end else
         result := true;
 end;