c++与C#结构体转换

[山叶溪]

C++的原结构体为
typedef struct
{
char IP[32]; //服务器地址
short port; //端口号
char group[64];
char user[64]; //登录用户名
char passwd[64]; //登录密码
} GE_SERVERPARAMETER
我转化成c#为：
struct GE_PSERVERPARAMETER
{
[MarshalAs(UnmanagedType.ByValArray, SizeConst = 32)]
public char[] IP;
public Int16 port;
[MarshalAs(UnmanagedType.ByValArray, SizeConst = 64)]
public char[] group;
[MarshalAs(UnmanagedType.ByValArray, SizeConst = 64)]
public char[] user;
[MarshalAs(UnmanagedType.ByValArray, SizeConst = 64)]
public char[] passwd; //登录密码
}
在主程序中调用赋值：
GE_PSERVERPARAMETER geps;
string s = "192.168.0.11";

geps.IP = s.ToCharArray();
geps.group = "test";
geps.passwd = "test";
geps.port = 9900;
geps.user = "test";
bool connected = UseDll.GE_ConnectServer(m, geps);//m是我程序中的一个整型变量应该没问题
MessageBox.Show(connected.ToString())
运行后出现错误：
未能封送类型，因为嵌入数组实例的长度与布局中声明的长度不匹配。
于是我又改为：
[MarshalAs(UnmanagedType.ByValTStr, SizeConst = 32)]
public string IP;
public Int16 port;
[MarshalAs(UnmanagedType.ByValTStr, SizeConst = 64)]
public string group;
[MarshalAs(UnmanagedType.ByValTStr, SizeConst = 64)]
public string user;
[MarshalAs(UnmanagedType.ByValTStr, SizeConst = 64)]
public string passwd; //登录密码

在主程序中调用赋值：
GE_PSERVERPARAMETER geps;
geps.IP = "122.193.4.19";
geps.group = "test";
geps.passwd = "gest";
geps.port = 9900;
geps.user = "test";
bool connected = UseDll.GE_ConnectServer(m, geps);//m是我程序中的一个整型变量应该没问题
MessageBox.Show(connected.ToString());
运行后出现错误“尝试读取或写入受保护的内存。这通常指示其他内存已损坏。”
搞不明白我这两种写法错在哪，应该怎么写，望高手指教

[cnfixit]

这是Mircrosoft P/Invoke Interop Assistant生成的

[System.Runtime.InteropServices.StructLayoutAttribute(System.Runtime.InteropServices.LayoutKind.Sequential, CharSet=System.Runtime.InteropServices.CharSet.Ansi)]
public struct Anonymous_4ad7ceb4_c3e2_49fa_8fcf_dc5708e66414 {
    
    /// char[32]
    [System.Runtime.InteropServices.MarshalAsAttribute(System.Runtime.InteropServices.UnmanagedType.ByValTStr, SizeConst=32)]
    public string IP;
    
    /// short
    public short port;
    
    /// char[64]
    [System.Runtime.InteropServices.MarshalAsAttribute(System.Runtime.InteropServices.UnmanagedType.ByValTStr, SizeConst=64)]
    public string group;
    
    /// char[64]
    [System.Runtime.InteropServices.MarshalAsAttribute(System.Runtime.InteropServices.UnmanagedType.ByValTStr, SizeConst=64)]
    public string user;
    
    /// char[64]
    [System.Runtime.InteropServices.MarshalAsAttribute(System.Runtime.InteropServices.UnmanagedType.ByValTStr, SizeConst=64)]
    public string passwd;
}