//转单精度浮点数
string hexString = "3D020938";
uint num = uint.Parse(hexString,System.Globalization.NumberStyles.AllowHexSpecifier);
byte[] floatVals = BitConverter.GetBytes(num);
this.textBox_code.Text= BitConverter.ToSingle(floatVals, 0).ToString();
//转double精度浮点数
string hexString = "409692A0B5DBAEC3"; // 示例十六进制数
long longValue = Convert.ToInt64(hexString, 16);
double doubleValue = BitConverter.Int64BitsToDouble(longValue);