c# struct 變數 到 byte[] 變數的轉換操作

如果能將 struct 變數 執行個體轉換成byte [] 類型，則可以方便我們將變數儲存傳遞壓縮等。以下是我的一個初步實現。

using System.Runtime.InteropServices;#region 需要轉換的結構  [StructLayout(LayoutKind.Sequential, Pack=1)]//struTest變數在記憶體中的對齊 （指標類型轉換成功的必要條件） public struct struTest{  public int intId;  public int intName;  public DateTime dtBegintime; } #endregion/// <summary> /// xamConverter 的摘要說明。 特定結構變數和byte[]之間的轉換操作 /// author:xam /// date:2007-4-23 /// note:apply convertion functions to deal with convertion between struct value and byte [] value; /// </summary> public class xamConverter {  #region 建構函式  public xamConverter()  {      //   // TODO: 在此處添加建構函式邏輯   //  }  #endregion  #region 方式一 通過指標類型的強制轉換    #region 結構變數到byte[]的轉換  /// <summary>  /// 結構變數到byte[]的轉換  /// </summary>  /// <param name="s">結構變數</param>  /// <returns>byte[](已指派空間)</returns>  public unsafe byte[] xamStructToBytes( struTest s ) {   byte[] arr = new byte[ sizeof(struTest) ];   fixed( byte* parr = arr ) {   *((struTest*)parr) = s; }   return arr;  }  #endregion  #region byte[] 到結構變數的轉換  /// <summary>  /// byte[] 到結構變數的轉換  /// </summary>  /// <param name="arr">byte[]</param>  /// <returns>結構變數</returns>  public unsafe struTest xamBytesToStruct( byte[] arr ) {   if( arr.Length < sizeof(struTest) )    throw new ArgumentException();   struTest s;   fixed( byte* parr = arr ) {   s = *((struTest*)parr); }   return s;  }  #endregion  #region 結構變數數組到byte[]的轉換  /// <summary>  /// 結構變數數組到byte[]的轉換  /// </summary>  /// <param name="s">結構變數數組</param>  /// <param name="tSize">結構變數數組的大小</param>  /// <returns>byte[]</returns>  public unsafe byte[] xamStructToBytes( struTest[] s,int tSize ) {   int i;   byte[] arr = new byte[ sizeof(struTest)*tSize ];   for(i=0;i<tSize;i++){        fixed( byte* parr = arr ) {          (((struTest*)parr)[i]) = s[i];     }   }   return arr;  }  #endregion  #region byte[] 到結構變數數組的轉換  /// <summary>  /// byte[] 到結構變數數組的轉換  /// </summary>  /// <param name="arr">byte[]</param>  /// <param name="tSize">byte[]包含的結構變數數組的大小</param>  /// <returns></returns>  public unsafe struTest[] xamBytesToStruct( byte[] arr,int tSize ) {   if( arr.Length < sizeof(struTest)*tSize )    throw new ArgumentException();   int i;   struTest[] s = new struTest[tSize];         for(i=0;i<tSize;i++){        fixed( byte* parr = arr ) {         s[i] = (((struTest*)parr)[i]);     }   }   return s;     }  #endregion  #endregion  #region 方式二     #region 結構變數到byte[]的轉換  /// <summary>  /// 結構變數到byte[]的轉換  /// </summary>  /// <param name="s">結構變數</param>  /// <returns>byte[](已指派空間)</returns>  public unsafe byte[] xamStructToBytesB( struTest s ) {      int size = Marshal.SizeOf(s);      System.IntPtr ptr = Marshal.AllocHGlobal(size);      Marshal.StructureToPtr(s, ptr,true);   byte[] ba=new byte[size];      Marshal.Copy(ptr, ba, 0, ba.Length );   return ba;  }  #endregion  #region byte[] 到結構變數的轉換  /// <summary>  /// byte[] 到結構變數的轉換  /// </summary>  /// <param name="arr">byte[]</param>  /// <returns>結構變數</returns>  public unsafe struTest xamBytesToStructB( byte[] arr ) {      struTest struReturn=new struTest();      int size = Marshal.SizeOf(struReturn);      System.IntPtr ptr = Marshal.AllocHGlobal(size);   Marshal.Copy(arr,0,ptr,arr.Length);   struReturn = (struTest)Marshal.PtrToStructure(ptr,struReturn.GetType());      return struReturn;  }  #endregion  #region 結構變數數組到byte[]的轉換  /// <summary>  /// 結構變數數組到byte[]的轉換  /// </summary>  /// <param name="s">結構變數數組</param>  /// <param name="tSize">結構變數數組的大小</param>  /// <returns>byte[]</returns>  public unsafe byte[] xamStructToBytesB( struTest[] s,int tSize ) {   int i;   int size = Marshal.SizeOf(s[0])*s.Length;      System.IntPtr [] ptrs = new IntPtr[s.Length];      for(i=0;i<tSize;i++){    ptrs[i] = Marshal.AllocHGlobal(size);    Marshal.StructureToPtr(s[i], ptrs[i],true);   }         byte[] ba=new byte[size];      for(i=0;i<tSize;i++){    Marshal.Copy(ptrs[i], ba, i*Marshal.SizeOf(s[0]), Marshal.SizeOf(s[0]) );   }   return ba;  }  #endregion  #region byte[] 到結構變數數組的轉換  /// <summary>  /// byte[] 到結構變數數組的轉換  /// </summary>  /// <param name="arr">byte[]</param>  /// <param name="tSize">byte[]包含的結構變數數組的大小</param>  /// <returns></returns>  public unsafe struTest[] xamBytesToStructB( byte[] arr,int tSize ) {   if( arr.Length < sizeof(struTest)*tSize )    throw new ArgumentException();         struTest[] struReturn=new struTest[tSize];   int intUnitSize = Marshal.SizeOf(struReturn[0]);   int size = intUnitSize*tSize;      int i;int intTemp;   System.IntPtr [] ptrs = new IntPtr[tSize];    for(i=0;i<tSize;i++){    intTemp = i*intUnitSize;    ptrs[i] = Marshal.AllocHGlobal(size);    Marshal.Copy(arr,intTemp,ptrs[i],intUnitSize);    struReturn[i] = (struTest)Marshal.PtrToStructure(ptrs[i],struReturn[i].GetType());   }      return struReturn;     }  #endregion  #endregion }

使用unsafe code 不安全的程式碼選項需開啟

示範

#region 結構數組測試   xamConverter xc = new xamConverter();   struTest[] st = new struTest[3];   st[0].intId = 1;   st[0].intName = 12;   st[0].dtBegintime = DateTime.Now;   st[2].intId = 2;   st[2].intName = 232;   st[2].dtBegintime = DateTime.Now;      byte [] inputBytes = xc.xamStructToBytesB(st,3);   struTest[] st2 = xc.xamBytesToStructB(inputBytes,3);      MessageBox.Show(st2[2].dtBegintime.ToString() + " =  " + st2[2].intName.ToString());   #endregion