DDC_GetNumDataValues shows error code 6202

[Takayama]

I am writing a wrapper in C# to read TDM files still.

But I met the error code 6202 using DDC_GetNumDataValues.

        [DllImport("nilibddc.dll", CallingConvention = CallingConvention.StdCall)]
        static extern int DDC_GetDataValues(IntPtr channel, ulong indexOfFirstValueToGet, ulong numberOfValuesToGet, IntPtr values);



IntPtr databuff = Marshal.AllocCoTaskMem((int)(sizeof(double) * numDataValues));
ret = DDC_GetDataValues(channels[i], 0, numDataValues, databuff);

Does Anyone know how to solve this error?

Thanks for any help.

[Takayama · Accepted solution]

I solved this issue myself.

I wronged the aggument's type.

[DllImport("nilibddc.dll")]
static extern int DDC_GetDataValues(IntPtr channel, uint indexOfFirstValueToGet, uint numberOfValuesToGet, IntPtr values);

IntPtr databuff = Marshal.AllocCoTaskMem((int)(sizeof(double) * numDataValues));
ret = DDC_GetDataValues(channels[i], (uint)0, (uint)numDataValues, databuff);

Thanks.