c# 字符串转换问题

[l2539641]

c# 字符串转换遇到个问题我要把字符串转换成十六进制插入到SQL表中，该类型为binary；
SqlCommand commm = new SqlCommand("update [user] set data=0x三千多省略了 where account='"+labAcc.Text+"'", conn);
这样是可以的，比如字符串str="32F01023DF也是三千的长度"要把他UPDATE到数据库把我难倒了试了很多转换都不行这个那个的错误都有，请教高手帮帮忙吧 谢谢了

[l2539641]

怎么都没人回答吗，简单的说就是把字符串update到数据类型为binary的字段中

[gomoku]

{
    SqlCommand commm = new SqlCommand("update [user] set data=@data where account='"+labAcc.Text+"'", conn); 

    SqlParameter dataParam = new SqlParameter("data", SqlDbType.Binary);  //<---
    dataParam.Value = GetBytes("32F01023DF");                             //<---
    commm.Parameters.Add(dataParam);                                      //<---

    conn.Open();
    commm.ExecuteNonQuery();
    conn.Close();
}

byte[] GetBytes(string hexString)
{
    byte[] result = new byte[hexString.Length / 2];
    for (int i = 0; i < result.Length; i++)
    {
        result[i] = Convert.ToByte(hexString.Substring(i + i, 2), 16);
    }
    return result;
}

It would be easier if you have a byte array at the beginning.

[yeah920]

帮忙up

[TonyWu66]

你用Parameters试一下

public static void AddEmployee(
  string lastName, 
  string firstName, 
  string title, 
  DateTime hireDate, 
  int reportsTo, 
  string photoFilePath, 
  string connectionString)
{
  byte[] photo = GetPhoto(photoFilePath);

  using (SqlConnection connection = new SqlConnection(
    connectionString))

  SqlCommand command = new SqlCommand(
    "INSERT INTO Employees (LastName, FirstName, " +
    "Title, HireDate, ReportsTo, Photo) " +
    "Values(@LastName, @FirstName, @Title, " +
    "@HireDate, @ReportsTo, @Photo)", connection); 

  command.Parameters.Add("@LastName",  
     SqlDbType.NVarChar, 20).Value = lastName;
  command.Parameters.Add("@FirstName", 
      SqlDbType.NVarChar, 10).Value = firstName;
  command.Parameters.Add("@Title",     
      SqlDbType.NVarChar, 30).Value = title;
  command.Parameters.Add("@HireDate", 
       SqlDbType.DateTime).Value = hireDate;
  command.Parameters.Add("@ReportsTo", 
      SqlDbType.Int).Value = reportsTo;

  command.Parameters.Add("@Photo",
      SqlDbType.Image, photo.Length).Value = photo;

  connection.Open();
  command.ExecuteNonQuery();
  }
}

public static byte[] GetPhoto(string filePath)
{
  FileStream stream = new FileStream(
      filePath, FileMode.Open, FileAccess.Read);
  BinaryReader reader = new BinaryReader(stream);

  byte[] photo = reader.ReadBytes((int)stream.Length);

  reader.Close();
  stream.Close();

  return photo;
}

[whitechololate]

[Quote=引用 2 楼 gomoku 的回复:]
C# code
{
SqlCommand commm = new SqlCommand("update [user] set data=@data where account='"+labAcc.Text+"'", conn);

SqlParameter dataParam = new SqlParameter("data", SqlDbType.Binary); //<---
dataParam.Value = GetBytes("32F01023DF"); //<---
commm.Parameters.Add(dataParam); //<---

conn.Open();
com…
[/Quote]

学习，

帮顶~

[liujt09]

2楼的方法就可以了啊！

[dlmeijianyu]

学习，

帮顶~

[hanyu0528]

学习啊~！！！

[birdlonger]

mark

[bianchenglangzi_110]

[Quote=引用 2 楼 gomoku 的回复:]
C# code
{
SqlCommand commm = new SqlCommand("update [user] set data=@data where account='"+labAcc.Text+"'", conn);

SqlParameter dataParam = new SqlParameter("data", SqlDbType.Binary); //<---
dataParam.Value = GetBytes("32F01023DF"); //<---
commm.Parameters.Add(dataParam); //<---

conn.Open();
com…
[/Quote]
学习！

[jasen520]

我刚测试过，2楼的方法就可以了！