.net - 如何在 C# 中编码(marshal) int*？

Question

我想在非托管库中调用此方法:

void __stdcall GetConstraints(

  unsigned int* puiMaxWidth,

  unsigned int* puiMaxHeight,

  unsigned int* puiMaxBoxes

);

我的解决方案:

• 委托(delegate)定义:

  [UnmanagedFunctionPointer(CallingConvention.StdCall)] 私有(private)委托(delegate) void GetConstraintsDel(UIntPtr puiMaxWidth, UIntPtr puiMaxHeight, UIntPtr puiMaxBoxes);

• 方法的调用:

  // PLUGIN NAME
  GetConstraintsDel getConstraints = (GetConstraintsDel)Marshal.GetDelegateForFunctionPointer(pAddressOfFunctionToCall, typeof(GetConstraintsDel));
  
   uint maxWidth, maxHeight, maxBoxes;
  
   unsafe
   {
      UIntPtr a = new UIntPtr(&maxWidth);
      UIntPtr b = new UIntPtr(&maxHeight);
      UIntPtr c = new UIntPtr(&maxBoxes);
      getConstraints(a, b, c);
   }
  

它有效，但我必须允许“不安全”标志。有没有不安全代码的解决方案？或者这个解决方案可以吗？我不太明白为项目设置不安全标志的含义。

感谢您的帮助!

Answer 1

刚出uint？

即:

HRESULT GetTypeDefProps (
   [in]  mdTypeDef   td,
   [out] LPWSTR      szTypeDef,
   [in]  ULONG       cchTypeDef,
   [out] ULONG       *pchTypeDef,
   [out] DWORD       *pdwTypeDefFlags,
   [out] mdToken     *ptkExtends
);

适用于:

uint GetTypeDefProps
(
  uint td, 
  [MarshalAs(UnmanagedType.LPArray, SizeParamIndex=2)]char[] szTypeDef, 
  uint cchTypeDef, 
  out uint pchTypeDef, 
  out uint pdwTypeDefFlags, 
  out uint ptknds
 );

使用示例；

char[] SzTypeDef;
uint CchTypeDef;
uint PchMember;
IntPtr PpvSigBlob;
uint PbSigBlob;

  SzTypeDef= new char[500];
  CchTypeDef= (uint)SzTypeDef.Length;

ResPT= 
  MetaDataImport.GetTypeDefProps
  (
    td, 
    SzTypeDef, 
    CchTypeDef, 
    out pchTypeDef, 
    out pdwTypeDefFlags,
    out ptkExtends
  );