C＃-通过LPVARIANT调用非托管C ++函数

short LS_LoadConfig(LS_ID SensorID,LPVARIANT varConfigPathFile,BOOL bInit)

[DllImport(\"LineSensor.dll\", EntryPoint = \"#16\")]
private static extern Int16 LS_LoadConfig(
        Int16 deviceId,
        IntPtr variantFilePath,
        int init);

string filepath = @\"C:\\Windows\\ ...\";
IntPtr variantFilePath = Marshal.AllocCoTaskMem(200);
Marshal.GetNativeVariantForObject(filepath, variantFilePath);
LS_LoadConfig(device.Id, variantFilePath, initLineSensor);

[DllImport(\"LineSensor.dll\", EntryPoint = \"#16\")]
    private static extern Int16 LS_LoadConfig(
        Int16 deviceId,
        int variantFilePath,
        int init);