如何从 ASP.NET C# 中的 SqlDataSource 获取特定的行值？

Posted 2023-02-19

【中文标题】如何从 ASP.NET C# 中的 SqlDataSource 获取特定的行值？

【英文标题】：How to get specific row value from SqlDataSource in ASP.NET C#?

【发布时间】：2021-10-26 22:18:33

【问题描述】：

如何通过 SQLDataSource 工具获取存在 SQL Server 数据库的特定值，用于比较两个值，一个是加密的，另一个是从密码文本框获取的，如下面的代码，在 (ASPxLabel) 上不显示任何输出？ 请建议获得解决方案。

protected void ASPxButton1_Click(object sender, EventArgs e)
    
    DataView dview (DataView)SqlDataSource1.Select(DataSourceSelectArguments.Empty);
    
    for (int i = 0; i < dview.Count ; i++)
    
       string view = (String)dview.Table.Rows[i][2];
        
        string st = Convert.ToString(view);
           
          if ( VerifyHash("Admin", "SHA512",st))
        
            ASPxLabel1.Text = "Correct";
        
        else
        
            ASPxLabel1.Text = "Incorrect";
        
    


public static bool VerifyHash(string plainText, string hashAlgorithm, string hashValue)


    // Convert base64-encoded hash value into a byte array.
    byte[] hashWithSaltBytes = Convert.FromBase64String(hashValue);

    // We must know size of hash (without salt).
    int hashSizeInBits, hashSizeInBytes;

    // Make sure that hashing algorithm name is specified.
    if (hashAlgorithm == null)
        hashAlgorithm = "";

    // Size of hash is based on the specified algorithm.
    switch (hashAlgorithm.ToUpper())
    

        case "SHA384":
            hashSizeInBits = 384;
            break;

        case "SHA512":
            hashSizeInBits = 512;
            break;

        default: // Must be MD5
            hashSizeInBits = 128;
            break;
    

    // Convert size of hash from bits to bytes.
    hashSizeInBytes = hashSizeInBits / 8;

    // Make sure that the specified hash value is long enough.
    if (hashWithSaltBytes.Length < hashSizeInBytes)
        return false;

    // Allocate array to hold original salt bytes retrieved from hash.
    byte[] saltBytes = new byte[hashWithSaltBytes.Length - hashSizeInBytes];

    // Copy salt from the end of the hash to the new array.
    for (int i = 0; i < saltBytes.Length; i++)
        saltBytes[i] = hashWithSaltBytes[hashSizeInBytes + i];

    // Compute a new hash string.
    string expectedHashString = ComputeHash(plainText, hashAlgorithm, saltBytes);

    // If the computed hash matches the specified hash,
    // the plain text value must be correct.
    return (hashValue == expectedHashString);


public static string ComputeHash(string plainText, string hashAlgorithm, byte[] saltBytes)

    // If salt is not specified, generate it.
    if (saltBytes == null)
    
        // Define min and max salt sizes.
        int minSaltSize = 4;
        int maxSaltSize = 8;

        // Generate a random number for the size of the salt.
        Random random = new Random();
        int saltSize = random.Next(minSaltSize, maxSaltSize);

        // Allocate a byte array, which will hold the salt.
        saltBytes = new byte[saltSize];

        // Initialize a random number generator.
        RNGCryptoServiceProvider rng = new RNGCryptoServiceProvider();

        // Fill the salt with cryptographically strong byte values.
        rng.GetNonZeroBytes(saltBytes);
    

    // Convert plain text into a byte array.
    byte[] plainTextBytes = Encoding.UTF8.GetBytes(plainText);

    // Allocate array, which will hold plain text and salt.
    byte[] plainTextWithSaltBytes =
    new byte[plainTextBytes.Length + saltBytes.Length];

    // Copy plain text bytes into resulting array.
    for (int i = 0; i < plainTextBytes.Length; i++)
        plainTextWithSaltBytes[i] = plainTextBytes[i];

    // Append salt bytes to the resulting array.
    for (int i = 0; i < saltBytes.Length; i++)
        plainTextWithSaltBytes[plainTextBytes.Length + i] = saltBytes[i];

    HashAlgorithm hash;

    // Make sure hashing algorithm name is specified.
    if (hashAlgorithm == null)
        hashAlgorithm = "";

    // Initialize appropriate hashing algorithm class.
    switch (hashAlgorithm.ToUpper())
    

        case "SHA384":
            hash = new SHA384Managed();
            break;

        case "SHA512":
            hash = new SHA512Managed();
            break;

        default:
            hash = new MD5CryptoServiceProvider();
            break;
    

    // Compute hash value of our plain text with appended salt.
    byte[] hashBytes = hash.ComputeHash(plainTextWithSaltBytes);

    // Create array which will hold hash and original salt bytes.
    byte[] hashWithSaltBytes = new byte[hashBytes.Length +
    saltBytes.Length];

    // Copy hash bytes into resulting array.
    for (int i = 0; i < hashBytes.Length; i++)
        hashWithSaltBytes[i] = hashBytes[i];

    // Append salt bytes to the result.
    for (int i = 0; i < saltBytes.Length; i++)
        hashWithSaltBytes[hashBytes.Length + i] = saltBytes[i];

    // Convert result into a base64-encoded string.
    string hashValue = Convert.ToBase64String(hashWithSaltBytes);

    // Return the result.
    return hashValue;

【参考方案1】：

您可以使用 DataRowView 从数据中获取特定的行值 DataRowView 是来自 DataView 的 DataRow

DataRowView rowView = dview[0];

或者您可以在 linq 查询中使用索引来获取特定的行数据。

【讨论】：

感谢您的回复，感谢您的回复，但仍然没有结果。