(IEEE-754) 字節數組與浮點數之間的互相轉換(MODBUS float類型)

在做上位機開發過程中，經常會碰到字節數組與浮點數，整數等數據之間的轉換，有時為了驗證數據是否解析正確，得借助於IEEE浮點數工具，本文把基於c#實現的浮點數與字節數組（或16進制的字符串)轉換的實現方法分享如下：

 

       /// <summary>
         /// 將二進制值轉ASCII格式十六進制字符串
         /// </summary>
         /// <paramname="data">二進制值</param>
         /// <paramname="length">定長度的二進制</param>
         /// <returns>ASCII格式十六進制字符串</returns>
         public static string toHexString(int data, int length)
         {
             string result = "";
             if (data > 0)
                 result = Convert.ToString(data, 16).ToUpper();
             if (result.Length < length)
             {
                 // 位數不夠補0
                 StringBuilder msg = new StringBuilder(0);
                 msg.Length = 0;
                 msg.Append(result);
                 for (; msg.Length < length; msg.Insert(0, "0")) ;
                 result = msg.ToString();
             }
             return result;
         }
         ///<summary>
         /// 將浮點數轉ASCII格式十六進制字符串（符合IEEE-754標准（32））
         /// </summary>
         /// <paramname="data">浮點數值</param>
         /// <returns>十六進制字符串</returns>
         public static string FloatToIntString(float data)
         {
             byte[] intBuffer = BitConverter.GetBytes(data);
             StringBuilder stringBuffer = new StringBuilder(0);
             for (int i = 0; i < intBuffer.Length; i++)
             {
                 stringBuffer.Insert(0, toHexString(intBuffer[i] & 0xff, 2));
             }
             return stringBuffer.ToString();
         }

        /// <summary>
         /// 將ASCII格式十六進制字符串轉浮點數（符合IEEE-754標准（32））
         /// </summary>
         /// <param name="data">16進制字符串</param>
         /// <returns></returns>
         public static float StringToFloat(String data)
         {
             if (data.Length < 8 || data.Length > 8)
             {
                 //throw new NotEnoughDataInBufferException(data.length(), 8);
                 return 0;
             }
             else
             {
                 byte[] intBuffer = new byte[4];
                 // 將16進制串按字節逆序化（一個字節2個ASCII碼）
                 for (int i = 0; i < 4; i++)
                 {
                     intBuffer[i] = Convert.ToByte(data.Substring((3 - i) * 2, 2), 16);
                 }
                 return BitConverter.ToSingle(intBuffer, 0);
             }
         }
         /// <summary>
         /// 將byte數組轉為浮點數
         /// </summary>
         /// <param name="bResponse">byte數組</param>
         /// <returns></returns>
         public static float ByteToFloat(byte[] bResponse)
         {
             if (bResponse.Length < 4 || bResponse.Length > 4)
             {
                 //throw new NotEnoughDataInBufferException(data.length(), 8);
                 return 0;
             }
             else
             {
                 byte[] intBuffer = new byte[4];
                 //將byte數組的前后兩個字節的高低位換過來
                 intBuffer[0] = bResponse[1];
                 intBuffer[1] = bResponse[0];
                 intBuffer[2] = bResponse[3];
                 intBuffer[3] = bResponse[2];
                 return BitConverter.ToSingle(intBuffer, 0);
             }
         }
         /// <summary>
         /// 用指針方式強制將byte數組轉為浮點數
         /// </summary>
         /// <param name="bResponse"></param>
         /// <returns></returns>
         public static float BytetoFloatByPoint(byte[] bResponse)
         {
             //uint nRest = ((uint)response[startByte]) * 256 + ((uint)response[startByte + 1]) + 65536 * ((uint)response[startByte + 2]) * 256 + ((uint)response[startByte + 3]);
             float fValue = 0f;
             uint nRest = ((uint)bResponse[0]) * 256
                 + ((uint)bResponse[1]) +
                 65536 * (((uint)bResponse[2]) * 256 + ((uint)bResponse[3]));
             //用指針將整形強制轉換成float
             unsafe
             {
                 float* ptemp;
                 ptemp = (float*)(&nRest);
                 fValue = *ptemp;
             }
             return fValue;
         }

 

 

注意：有時從串口（或其它設備讀到的字節有高低位之分，在作為參數傳遞前把他們的順序調整過來即可)