您没有名为的参数@name 在您的SQL语句中。也许你想选择它像

You don't have a parameter called @name in your SQL statement. Perhaps you wanted to select it like

SELECT Name FROM NewsClip_Login WHERE Username = @Username AND Password = @Password";

如果您正在尝试这样做，那么您可以参考结果列wiuthout @，因为它用于参数。



关于密码的另一件事。永远不要将密码存储为纯文本。它们应始终单向散列。请查看密码存储：怎么做。 [ ^ ]



ADDITION

--------- -

If that is what you're trying to do then you refer to the result columns wiuthout @ since that is used for parameters.

Another thing concerning the password. Never ever store the passwords as plain text. They should always be hashed one-way. Have a look at Password Storage: How to do it.[^]

ADDITION
-----------

string queryText = @"SELECT Name FROM NewsClip_Login WHERE Username = @Username AND Password = @Password";

using (SqlConnection cn = new SqlConnection("Data Source=PRIMO-CHALICE;Initial Catalog=NewsClip;Integrated Security=True")) {
   using (SqlCommand cmd = new SqlCommand(queryText, cn))
   {
      cn.Open();
      cmd.Parameters.AddWithValue("@Username", UsernameTextBox.Text);
      cmd.Parameters.AddWithValue("@Password", PasswordTextBox.Text);
      SqlDataReader reader = cmd.ExecuteReader();

      reader.Read();
      NameLabel.Text = reader["Name"].ToString();
      NameLabelText = NameLabel.Text;
      reader.Close();
      ...

抱歉，我没有意识到您的SQL语句没有名称列

Sorry I didn't realize that your SQL statement not having Name column

SELECT Count(*) FROM NewsClip_Login

如果您正在使用阅读器，则应该具有列名，例如，如果您要获取值那么你应该在你的select语句中有name列。



从阅读器中删除@它应该是reader [Name]

You should have columnname if you are using reader for example if you are fetching the value of name then you should have name column in your select statement.

Remove @ from the reader it should be reader ["Name"]