c#调用c++写的dll报错，尝试写入受保护的内存。。。求解答

Question

    private void button1_Click(object sender, EventArgs e)
    {

        IntPtr key = Marshal.AllocHGlobal(1024);
        //Marshal.ReleaseComObject(GenerateKeyEx);
        uint len = 4;
        string seed = "abcd";
        uint slen = (uint)seed.Length;
        uint sl = 1;
        uint keylen = 1024;
        int r = GenerateKeyEx(seed, slen, sl, "car", ref key, keylen, len);
        MessageBox.Show(key.ToString());


    }
    [DllImport("GenerateKey.dll",EntryPoint="GenerateKeyEx",CharSet=CharSet.Ansi,SetLastError=true,CallingConvention=CallingConvention.ThisCall)]

    public static extern int GenerateKeyEx(string ipSeedArray, uint iSeedArraySize,
        uint iSecurityLevel, string ipVariant, ref IntPtr iopKeyArray, uint iMaxKeyArraySize, uint oActualKeyArraySize);

Answer 1

指针操作肯定有问题。