How to marshal int* in C#?
I would like to call this method in unmanaged library:
void __stdcall GetConstraints(
unsigned int* puiMaxWidth,
unsigned int* puiMaxHeight,
unsigned int* puiMaxBoxes
);
My solution:
Delegate definition:
[UnmanagedFunctionPointer(CallingConvention.StdCall)] private delegate void GetConstraintsDel(UIntPtr puiMaxWidth, UIntPtr puiMaxHeight, UIntPtr puiMaxBoxes);
The call of the method:
// 开发者_如何学PythonPLUGIN 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); }
It works but I have to allow "unsafe" flag. Is there a solution without unsafe code? Or is this solution ok? I don't quite understand the implications of setting the project with unsafe flag.
Thanks for help!
Just out uint?
ie:
HRESULT GetTypeDefProps (
[in] mdTypeDef td,
[out] LPWSTR szTypeDef,
[in] ULONG cchTypeDef,
[out] ULONG *pchTypeDef,
[out] DWORD *pdwTypeDefFlags,
[out] mdToken *ptkExtends
);
works fine with:
uint GetTypeDefProps
(
uint td,
[MarshalAs(UnmanagedType.LPArray, SizeParamIndex=2)]char[] szTypeDef,
uint cchTypeDef,
out uint pchTypeDef,
out uint pdwTypeDefFlags,
out uint ptknds
);
Sample use;
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
);
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