Error Returning Float from C dll

[beto]

A am receiving an error when attempting to return a float from a C function.

The following is the C code

#define DLL __declspec(dllexport)

DLL float testfloat()
{
return 3.3;
}

The following is the C# code

[DllImport(".\\testfloat.DLL")]
static extern float testfloat();

float temp = testfloat();

Any help is appreciated.

 

[Jon Skeet [C# MVP]]

A am receiving an error when attempting to return a float from a C function.

What error are you receiving? I would also suggest that the interop
group might well give you useful answers, if no-one here knows.

 

[Steve Waggoner]

A am receiving an error when attempting to return a float from a C function.

The following is the C code

#define DLL __declspec(dllexport)

DLL float testfloat()
{
return 3.3;
}

The following is the C# code

[DllImport(".\\testfloat.DLL")]
static extern float testfloat();

try specifying the "__stdcall" calling convention for the C++ function
ex.

DLL float __stdcall testfloat()

 

[beto]

What error are you receiving? I would also suggest that the interop
group might well give you useful answers, if no-one here knows.

A managed NotSupportedException occurred at Application::Fun+0xf

 

[beto]

A am receiving an error when attempting to return a float from a C function.

The following is the C code

#define DLL __declspec(dllexport)

DLL float testfloat()
{
return 3.3;
}

The following is the C# code

[DllImport(".\\testfloat.DLL")]
static extern float testfloat();

try specifying the "__stdcall" calling convention for the C++ function
ex.

DLL float __stdcall testfloat()

Still received the same error message.

 

[beto]

The solution that ended up working was to return just an integer that
reported the final status of the dll. To return the float, a reference
was passed to the dll and then used by the C# application.

Example:
[DllImport(".\\testfloat.dll")]
static extern int testfloat([In, Out] float[] returnf);

float[] returnf = new float[] {0,0,0,0};
int status = testfloat(returnf);