使用DLLImport和dnlib

Question

我有一个C#项目，我想用dnlib修改它。我可以在很好的范围内添加代码。但是，我无法找到添加DLLImport的方法，所有的搜索结果都是干涸的。我怎么能做到这一点？能办到吗？

编辑：我挖掘了dnSpy的源代码并找到了一种方法。我把它放在这里是为了让每个人都能看到：

var _loadedEXE = ModuleDefMD.Load("EXE.exe");
var _dllReference = new ModuleRefUser(_loadedEXE, "DLL_NAME.dll");

var _flagsDLL = MethodAttributes.PinvokeImpl | MethodAttributes.Public | MethodAttributes.Static;
var _flagsPDLL = MethodImplAttributes.PreserveSig;

var _mapDLL = new ImplMapUser(_dllReference, "", PInvokeAttributes.CallConvCdecl);
            
var _method = new MethodDefUser("METHOD_NAME", MethodSig.CreateStatic(_loadedEXE.CorLibTypes.Int32, _loadedEXE.CorLibTypes.Int32), _flagsPDLL, _flagsDLL);
_method.ImplMap = _mapDLL;

这将导致dnSpy中的以下分解：

[DllImport("DLL_NAME.dll", CallingConvention = CallingConvention.Cdecl)]
public static extern int METHOD_NAME(int);

我希望这对你有帮助，这样你就不会像我一样受苦。

Answer 1

用dnlib实现VirtualProtect

[DllImport("kernel32.dll", CharSet = CharSet.Auto, CallingConvention = CallingConvention.Winapi)]
internal static extern bool VirtualProtect(IntPtr address, IntPtr size, uint newProtect, out uint oldProtect);

var virtualProtectNativeMethodAttributes = MethodAttributes.PinvokeImpl | MethodAttributes.Assembly | MethodAttributes.Static;
var virtualProtectNativeMethodImplementationAttributes = MethodImplAttributes.PreserveSig;

var dllReference = new ModuleRefUser(moduleDefMD, "kernel32.dll");
var nativeMethodName = "VirtualProtect";
var implementationMap = new ImplMapUser(dllReference, nativeMethodName, PInvokeAttributes.CharSetAuto | PInvokeAttributes.CallConvWinapi);

var virtualProtectNativeMethod = new MethodDefUser(nativeMethodName,
    MethodSig.CreateStatic(moduleDefMD.CorLibTypes.Boolean, moduleDefMD.CorLibTypes.IntPtr, moduleDefMD.CorLibTypes.IntPtr, moduleDefMD.CorLibTypes.UInt32, moduleDefMD.CorLibTypes.UInt32),
    virtualProtectNativeMethodImplementationAttributes, virtualProtectNativeMethodAttributes);

virtualProtectNativeMethod.ImplMap = implementationMap;
virtualProtectNativeMethod.ParamDefs.Add(new ParamDefUser("address", 1));
virtualProtectNativeMethod.ParamDefs.Add(new ParamDefUser("size", 2));
virtualProtectNativeMethod.ParamDefs.Add(new ParamDefUser("newProtect", 3));
virtualProtectNativeMethod.ParamDefs.Add(new ParamDefUser("oldProtect", 4, ParamAttributes.Out));