C# 调用C写的DLL时 对应的int* 类型返回值转化为 IntPtr

C中代码：

int* read( char *filename )
{
    .......
}

C#中代码：

[DllImport("myC.dll", EntryPoint = "read", CharSet = CharSet.Auto)]
public static extern IntPtr read(ref byte filename);

调用示例：

string name = @"d:\result\Gaussian_6_0.3.jpg";
            byte[] filename = new byte[100];
            for (int i = 0; i < name.Length; i++)
            {
                filename[i] = (byte)name[i];
            }
            IntPrt data = new IntPtr();
            data = liblept168.read(ref filename[0]);