按下按钮时 Windows 窗体冻结

Question

我正在尝试使用 sql 连接创建登录表单。当我按下登录按钮（按钮2）时，无论文本框中是否有文本，表单都会冻结。

using System;
using System.Data;
using System.Data.SqlClient;
using System.Windows.Forms; 



namespace Test2
{
    public partial class Form1 : Form
    {

        SqlConnection con = new SqlConnection(@"Data Source=(LocalDB)\\MSSQLLocalDB;AttachDbFilename=C:\\Users\\tfgge\\Documents\\BazaDate.mdf;Integrated Security=True;Connect Timeout=30;Encrypt=True");
       
        
        public Form1()
        {
            InitializeComponent();
            
        }

        private void label1_Click(object sender, EventArgs e)
        {

        }

        private void button1_Click(object sender, EventArgs e)
        {
            this.Close();
        }

        private void button2_Click(object sender, EventArgs e)
        {
            con.Open();
            SqlCommand cmd = new SqlCommand("select * from Autentificare where EmailUtiliz = @email and ParolaUtiliz = @parola", con);
            
            cmd.Parameters.AddWithValue("email", textBox1.Text);
            cmd.Parameters.AddWithValue("parola", textBox2.Text);
            var read = cmd.ExecuteReader();
            if(read.Read())
            {
                MessageBox.Show("Autentificare reusita");
            }
            else
            {
                MessageBox.Show("Autentificare esuata");
            }
        }

    }
}

我尝试使用私有类进行连接，但遇到了一些异常，这是我最终得到的变体。

Answer 1

执行命令后尝试关闭连接。

private void button2_Click(object sender, EventArgs e)
{
    try
    {
        con.Open();
        SqlCommand cmd = new SqlCommand("select * from Autentificare where EmailUtiliz = @email and ParolaUtiliz = @parola", con);
        
        cmd.Parameters.AddWithValue("@email", textBox1.Text);
        cmd.Parameters.AddWithValue("@parola", textBox2.Text);
        var read = cmd.ExecuteReader();
        if(read.Read())
        {
            MessageBox.Show("Autentificare reusita");
        }
        else
        {
            MessageBox.Show("Autentificare esuata");
        }
    }
    catch (Exception ex)
    {
        MessageBox.Show("Error: " + ex.Message);
    }
    finally
    {
        con.Close(); // Close the connection after executing the command
    }
}

Answer 2

我发现了几个问题。最直接的是使用双反斜杠字符和

@

逐字字符串前缀，但这里的其他更正也很重要：

public partial class Form1 : Form
{
    string cnString = @"Data Source=(LocalDB)\MSSQLLocalDB;AttachDbFilename=C:\Users\tfgge\Documents\BazaDate.mdf;Integrated Security=True;Connect Timeout=30;Encrypt=True";       
    
    private void button2_Click(object sender, EventArgs e)
    {
        using var con = new SqlConnection(cnString);
        using var cmd = new SqlCommand("SELECT ParolaUtiliz FROM Autentificare WHERE EmailUtiliz = @email", con);

        cmd.Parameters.Add("@email", SqlDbType.NVarchar, 60).Value = textBox1.Text;
        con.Open();
        var storedHash = (string)cmd.ExecuteScalar();

        //assuming the BCrypt.Net library on NuGet
        if (storedHash is object && BCrypt.Verify(textBox2.Text, storedHash))
        {
            MessageBox.Show("Autentificare reusita");
        }
        else
        {
            MessageBox.Show("Autentificare esuata");
        }
    }

}

另一件事：您确实应该为控件和事件方法提供更好的名称。以后你会感谢自己的。