NSIS：判断并安装.NET Framework的例子
现在.NET开发的软件已经大行其道，但有些操作系统并不符合软件的运行要求，所以，我们需要在安装程序中进行.NET Framework的判断，如果不符合要求就进行静默安装。
首先，我们在Function区段进行当前.NET版本判断：
Function GetNetFrameworkVersion
;获取.Net Framework版本,支持
Push $1
Push $0
ReadRegDWORD $0 HKLM "SOFTWARE\Microsoft\NET Framework Setup\NDP\v3.5" "Install"
ReadRegDWORD $1 HKLM "SOFTWARE\Microsoft\NET Framework Setup\NDP\v3.5" "Version"
StrCmp $0 1 KnowNetFrameworkVersion +1
ReadRegDWORD $0 HKLM "SOFTWARE\Microsoft\NET Framework Setup\NDP\v3.0\Setup" "InstallSuccess"
ReadRegDWORD $1 HKLM "SOFTWARE\Microsoft\NET Framework Setup\NDP\v3.0\Setup" "Version"
StrCmp $0 1 KnowNetFrameworkVersion +1
ReadRegDWORD $0 HKLM "SOFTWARE\Microsoft\NET Framework Setup\NDP\v2.0.50727" "Install"
ReadRegDWORD $1 HKLM "SOFTWARE\Microsoft\NET Framework Setup\NDP\v2.0.50727" "Version"
StrCmp $1 "" +1 +2
StrCpy $1 "2.0.50727.832"
StrCmp $0 1 KnowNetFrameworkVersion +1
ReadRegDWORD $0 HKLM "SOFTWARE\Microsoft\NET Framework Setup\NDP\v1.1.4322" "Install"
ReadRegDWORD $1 HKLM "SOFTWARE\Microsoft\NET Framework Setup\NDP\v1.1.4322" "Version"
StrCmp $1 "" +1 +2
StrCpy $1 "1.1.4322.573"
StrCmp $0 1 KnowNetFrameworkVersion +1
ReadRegDWORD $0 HKLM "SOFTWARE\Microsoft\.NETFramework\policy\v1.0" "Install"
ReadRegDWORD $1 HKLM "SOFTWARE\Microsoft\.NETFramework\policy\v1.0" "Version"
StrCmp $1 "" +1 +2
StrCpy $1 "1.0.3705.0"
StrCmp $0 1 KnowNetFrameworkVersion +1
StrCpy $1 "not .NetFramework"
KnowNetFrameworkVersion:
Pop $0
Exch $1
FunctionEnd
然后，在Section区段进行.NET静默安装
Section -.NET
Call GetNetFrameworkVersion
Pop $R1
${If} $R1 < '2.0.50727'
SetDetailsPrint textonly
DetailPrint "正在安装 .NET Framework 2.0 SP2..."
SetDetailsPrint listonly
SetOutPath "$TEMP"
SetOverwrite on
File "NetFx20SP2_x86.exe"
ExecWait '$TEMP\NetFx20SP2_x86.exe /quiet /norestart' $R1
Delete "$TEMP\NetFx20SP2_x86.exe"
${EndIf}
SectionEnd
当然，在Section区段可以做到自动在线下载而不把.NET打到安装包中，这样可以减小安装包体积，效果可参考紫辰记账本安装程序。