结构体定义如下
[StructLayoutAttribute(LayoutKind.Sequential, CharSet = CharSet.Ansi, Pack = 1)]
struct TMsgHeadInfo
{
[MarshalAs(UnmanagedType.ByValArray, SizeConst = 2)]
public char[] MsgCode;
[MarshalAs(UnmanagedType.ByValArray, SizeConst = 2)]
public char[] MsgType;
public byte SenderType;
[MarshalAs(UnmanagedType.ByValArray, SizeConst = 6)]
public char[] Sender;
public byte ReceiverType;
[MarshalAs(UnmanagedType.ByValArray, SizeConst = 6)]
public char[] Receiver;
public int TotalLength;
[MarshalAs(UnmanagedType.ByValArray, SizeConst = 32)]
public char[] VerifyCode;
public TMsgHeadInfo(int MsgLength)
{
MsgCode = new char[2];
MsgType = new char[2];
SenderType = 1;
Sender = new char[6];
ReceiverType = 4;
Receiver = new char[6];
TotalLength = MsgLength;
VerifyCode = new char[32];
}
}
[StructLayoutAttribute(LayoutKind.Sequential, CharSet = CharSet.Ansi, Pack = 1)]
public struct TDevInfo
{
public byte DevType;
[MarshalAs(UnmanagedType.ByValArray, SizeConst = 10)]
public char[] DevCode;
[MarshalAs(UnmanagedType.ByValArray, SizeConst = 14)]
public char[] CheckTime;
[MarshalAs(UnmanagedType.ByValArray, SizeConst = 20)]
public char[] ErrorStr;
public Int32 CheckError;
public TDevInfo(byte ADevType)
{
DevType = ADevType;
DevCode = new char[10];
CheckTime = new char[14];
ErrorStr = new char[20];
CheckError = 0;
}
}
[StructLayoutAttribute(LayoutKind.Sequential, CharSet = CharSet.Ansi, Pack = 1)]
struct TLabelContent
{
public int PosX;
public int PosY;
public int Flag;
public int Flv;
[MarshalAs(UnmanagedType.ByValArray, SizeConst = 255)]
public char[] FileName;
[MarshalAs(UnmanagedType.ByValArray, SizeConst = 255)]
public char[] strContent;
[MarshalAs(UnmanagedType.ByValArray, SizeConst = 12)]
public char[] strColor;
[MarshalAs(UnmanagedType.ByValArray, SizeConst = 12)]
public char[] strBkColor;
public int Space;
public int Font;
public int FontHeight;
public int FontWidth;
public TLabelContent(int AFlag)
{
PosX = 0;
PosY = 0;
Flag = AFlag;
Flv = 0;
FileName = new char[255];
strContent = new char[255];
strColor = new char[12];
strBkColor = new char[12];
Space = 0;
Font = 0;
FontHeight = 0;
FontWidth = 0;
}
}
[StructLayoutAttribute(LayoutKind.Sequential, CharSet = CharSet.Ansi, Pack = 1)]
struct TPlayList
{
public int ActTime;
public int Action;
public int Speed;
public int ListNum;
public TLabelContent[] Content;
public TPlayList(int count)
{
ActTime = 0;
Action = 0;
Speed = 0;
ListNum = count;
Content = new TLabelContent[count];
}
}
//下发节目单
[StructLayoutAttribute(LayoutKind.Sequential, CharSet = CharSet.Ansi, Pack = 1)]
struct TPlayListInfo
{
public byte DevType;
[MarshalAs(UnmanagedType.ByValArray, SizeConst = 10)]
public char[] DevCode;
public int Page;
public TPlayList[] PlayList;
public TPlayListInfo(int count)
{
DevType = 1;
DevCode = new char[10];
Page = 0;
PlayList = new TPlayList[count];
}
}
//下发报文
[StructLayoutAttribute(LayoutKind.Sequential, CharSet = CharSet.Ansi, Pack = 1)]
struct TPlayListMsg
{
public TMsgHeadInfo MsgHead;
public TPlayListInfo PlayListInfo;
public TPlayListMsg(int count)
{
MsgHead = new TMsgHeadInfo();
PlayListInfo = new TPlayListInfo();
}
}
为什么
TPlayListMsg msg = new TPlayListMsg();
MessageBox.Show(Marshal.SizeOf(msg).ToString());
获得的大小是77，如何才能正确计算出结构体的大小呢
------解决思路----------------------
没看懂
public TPlayListMsg(int count)这个构造函数没用上?
你用的是默认的隐藏无参数构造函数实例化的结构体啊
------解决思路----------------------
看了一下代码,你最终的结构体大小明显和传入的count有关
而这个count你根本没有传入
------解决思路----------------------
public TPlayList[] PlayList; 问题在于这里吧，他认不到了。
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既然你的构造函数带参数
你应该TPlayListMsg msg = new TPlayListMsg(10);啊
为什么先用无参数的构造函数实例化,再到结构体里面去循环赋值?
这结构体真的是你自己写的吗,怎么感觉你自己都不会用的
------解决思路----------------------
知道为啥是固定的77了
他是只算了
public TMsgHeadInfo MsgHead;
public TPlayListInfo PlayListInfo;
这两个结构里面的基本类型的字段
然而里面的
public TLabelContent[] Content;
TPlayList[] PlayList 这个他实际只是取得 这个Content，PlayList的指针地址的长度也就是8
而你要取的是每个Content与PlayList实际New 后每个项的长度之和。。。
这个搞不了
------解决思路----------------------
77是对的，算法如下：
2+2+1+6+1+6+4+32+（这是TMsgHeadInfo的长度）
1+10+4+8（这是TPlayListInfo的长度）
正好是77，一点没错。
从你的发言中，可以看出你根本不会VC++，所以写的C#代码也是半桶水。
在VC++里面，数组是定长的，就不存在可变长度数组，定义的时候必须指定长度，但是你看你定义的TPlayListInfo中，“public TPlayList[] PlayList;”就没指定长度，你希望在运行时动态给长度，这种做法在C++里面你试试，你能定义一个运行时动态改变长度的结构体吗？除非用指针，否则变长数组肯定不行。因此这里在计算时，系统用了Inptr的长度，也就是8字节。
------解决思路----------------------
你编译了没？长度明明是输出28529的，居然说是77。我就不上图了，你自己认证检查下程序的修改日期，是不是执行的老的程序。