如何在C＃中读取SQL的varbinary作为字符串？ [英] How to read varbinary of SQL as string in C#?

问题描述

我有一个Web应用程序，它从SQL中读取varbinary作为代码中的字节数组。基本上它会执行列的ExecuteScalar并将其作为字节数组返回。



我现在正在将该应用程序的迷你版本作为Windows应用程序。为此，我试图跳过数据库连接。我直接从SQL输入varbinary值到RichTextBox并尝试将其作为字节数组读取。但是，我没有得到相同的字节数组。我做错了什么，我该怎么办？



基本上，我手头有varbinary值（例如：B0015379737）。这是我从SQL中获取的varbinary值。现在，我想简单地将此值粘贴到文本框中，并将其作为字节数组读取。基本上源是varbinary。我将输入作为字符串，我希望输出为字节数组，匹配源varbinary

I have an web application which reads varbinary from SQL as a byte array in code. Basically it does a ExecuteScalar of the column and returns it as a byte array.

I am now doing a mini version of the application as a Windows application. For this, I am trying to skip the DB connection. I am directly inputting the varbinary value from SQL to a RichTextBox and trying to read it as a byte array. However, I do not get the same byte array. What am I doing wrong and how should I proceed ?

Basically, I have in hand the varbinary value (eg: "B0015379737"). This is a varbinary value i have taken from SQL. Now, I want to simply paste this value in a textbox and read it as byte array. Basically the source is varbinary. I am giving input as a string and I want the output as byte array which matches the source varbinary

推荐答案

根据使用的编码，使用以下代码：

Hi,

Depending on which encoding was used, use the following code:

byte[] binaryString = (byte[])reader[1];

// if the original encoding was ASCII
string ascii = Encoding.ASCII.GetString(binaryString);

// if the original encoding was UTF-8
string utf = Encoding.UTF8.GetString(binaryString);

// if the original encoding was UTF-16
string utfs = Encoding.Unicode.GetString(binaryString);

如果从十六进制开始表示值，并且您希望使用它，您必须分几步执行：



- 首先，转换字节数组的十六进制字符串表示形式转换为字节数组



- 其次，将此字节数组传递给所选编码的GetString（）方法。



类似于：

If you start from the hexadecimal representation of the value, and you want to work with it, you have to do it in several steps:

- First, translate this hexadecimal string representation of a byte array into a byte array

- Second, pass this byte array to the GetString() method of the chosen Encoding.

Something like:

using System.Globalization;
using System.Text;

public static byte[] ByteArrayFromHexaString(string hexa) {
   int length = hexa.Length;
   List<byte> result = new List<byte>();
   // Fetch whether there are an odd or even number of chars
   bool isOdd = ((length & 1) == 1);
   if (isOdd) {
      result.Add(byte.Parse(hexa[0], NumberStyles.HexNumber));
   }
   string s;
   for (int i = (isOdd) ? 1 : 0; i < length; i += 2) {
      s = hexa.SubString(i, 2);
      result.Add(byte.Parse(s, NumberStyles.HexNumber));
   }
   return result.ToArray();
}

public static string StringFromByteArray(byte[] bytes, Encoding encoding) {
   return encoding.GetString(bytes);
}

现在，您需要两种方法从其编码原始值的十六进制表示中获取字符串。< br $> b $ b

祝你好运。希望这有帮助。

You now have both methods you need to get a string from the hexadecimal representation of its encoded raw value.

Good luck. Hope this helps.

我用这段代码得到它

I got it using this piece of code

string hex = richTextBox1.Text
int NumberChars = hex.Length;
byte[] bytes = new byte[NumberChars / 2];
for (int i = 0; i < NumberChars; i += 2)
bytes[i / 2] = Convert.ToByte(hex.Substring(i, 2).ToString(), 16);
return bytes;

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