ilspy-decompile

使用 ILSpy 反编译 .NET 程序集

使用此技能，通过反编译已编译的程序集来了解 .NET 代码的内部工作原理。

快速开始

# Decompile an assembly to stdout (no install needed with .NET 10+)
dnx ilspycmd MyLibrary.dll

# Decompile to an output folder
dnx ilspycmd -o output-folder MyLibrary.dll

常见的 .NET 程序集位置

NuGet 包

# Windows
~/.nuget/packages/<package-name>/<version>/lib/<tfm>/

# Example: Newtonsoft.Json
~/.nuget/packages/newtonsoft.json/13.0.3/lib/netstandard2.0/Newtonsoft.Json.dll

# Example: Microsoft.Extensions.DependencyInjection
~/.nuget/packages/microsoft.extensions.dependencyinjection/8.0.0/lib/net8.0/Microsoft.Extensions.DependencyInjection.dll

.NET 运行时库

# Find .NET install location
dotnet --list-runtimes

# Windows typical paths
C:/Program Files/dotnet/shared/Microsoft.NETCore.App/<version>/
C:/Program Files/dotnet/shared/Microsoft.AspNetCore.App/<version>/

# Linux/macOS typical paths
/usr/share/dotnet/shared/Microsoft.NETCore.App/<version>/
/usr/share/dotnet/shared/Microsoft.AspNetCore.App/<version>/

# Example: System.Text.Json from runtime
C:/Program Files/dotnet/shared/Microsoft.NETCore.App/8.0.0/System.Text.Json.dll

.NET SDK 参考程序集

# Find SDK location
dotnet --list-sdks

# Reference assemblies (design-time facades)
C:/Program Files/dotnet/packs/Microsoft.NETCore.App.Ref/<version>/ref/net8.0/

项目构建输出

# Debug build
./bin/Debug/net8.0/<AssemblyName>.dll

# Published output
./bin/Release/net8.0/publish/<AssemblyName>.dll

核心工作流程

1. 确定要了解的内容（API、类、方法）
2. 找到包含该代码的程序集
3. 使用 dnx ilspycmd -l class 查找确切的类型名称
4. 使用 -t 反编译指定类型

命令

基本反编译

# Decompile to stdout
dnx ilspycmd MyLibrary.dll

# Decompile to output directory
dnx ilspycmd -o ./decompiled MyLibrary.dll

# Decompile as compilable project
dnx ilspycmd -p -o ./project MyLibrary.dll

# Decompile with nested namespace folders
dnx ilspycmd -p -o ./project --nested-directories MyLibrary.dll

针对性反编译

# Decompile a specific type
dnx ilspycmd -t Namespace.ClassName MyLibrary.dll

# Decompile with specific C# version
dnx ilspycmd -lv CSharp12_0 MyLibrary.dll

# Decompile with reference path for dependencies
dnx ilspycmd -r ./dependencies MyLibrary.dll

查看 IL 代码

# Show IL code instead of C#
dnx ilspycmd -il MyLibrary.dll

# Show IL for specific type
dnx ilspycmd -il -t Namespace.ClassName MyLibrary.dll

列出类型

# List all classes
dnx ilspycmd -l class MyLibrary.dll

# List interfaces
dnx ilspycmd -l interface MyLibrary.dll

# List structs
dnx ilspycmd -l struct MyLibrary.dll

# List enums
dnx ilspycmd -l enum MyLibrary.dll

# List delegates
dnx ilspycmd -l delegate MyLibrary.dll

选项

# Show help
dnx ilspycmd -h

# Disable update check (useful for CI/automation)
dnx ilspycmd --disable-updatecheck MyLibrary.dll

# Remove dead code
dnx ilspycmd --no-dead-code MyLibrary.dll

示例：了解 JsonSerializer 的工作原理

# Find System.Text.Json in the runtime
dotnet --list-runtimes
# Microsoft.NETCore.App 8.0.0 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]

# List classes to find JsonSerializer
dnx ilspycmd -l class "C:/Program Files/dotnet/shared/Microsoft.NETCore.App/8.0.0/System.Text.Json.dll"

# Decompile JsonSerializer
dnx ilspycmd -t System.Text.Json.JsonSerializer "C:/Program Files/dotnet/shared/Microsoft.NETCore.App/8.0.0/System.Text.Json.dll"

示例：检查 NuGet 包的实现

# Decompile Polly's retry logic
dnx ilspycmd -t Polly.Retry.RetryPolicy ~/.nuget/packages/polly/8.0.0/lib/netstandard2.0/Polly.dll

# Decompile entire package to project for exploration
dnx ilspycmd -p -o ./polly-src ~/.nuget/packages/polly/8.0.0/lib/netstandard2.0/Polly.dll

示例：查看 ASP.NET Core 如何处理请求

# Find the ASP.NET Core runtime
# C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App\8.0.0\

# Decompile the Kestrel server
dnx ilspycmd -l class "C:/Program Files/dotnet/shared/Microsoft.AspNetCore.App/8.0.0/Microsoft.AspNetCore.Server.Kestrel.Core.dll"

dnx ilspycmd -t Microsoft.AspNetCore.Server.Kestrel.Core.KestrelServer "C:/Program Files/dotnet/shared/Microsoft.AspNetCore.App/8.0.0/Microsoft.AspNetCore.Server.Kestrel.Core.dll"

示例：比较 C# 和 IL

# View C# source
dnx ilspycmd -t MyNamespace.MyClass MyLibrary.dll

# View IL code for same type
dnx ilspycmd -il -t MyNamespace.MyClass MyLibrary.dll

C# 语言版本

-lv 选项可用的版本：

• CSharp1 至 CSharp12_0
• Latest、Preview