Question

我尝试识别数据库，创建一个Login函数。每次按下按钮我都会收到此错误：System.InvalidOperationException：连接未打开。 at MySql.Data.MySqlClient.MySqlConnection.Throw（Exception ex）at MySql.Data.MySqlClient.MySqlCommand.Throw（Exception ex）at MySql.Data.MySqlClient.MySqlCommand.Prepare（）at start.CheckUserLogin（String username，String password））在c：\ Users \ RARES \ Documents \ Visual Studio 2010 \ WebSites \ tem1 \ start.aspx.cs：第46行

请告诉我如何阅读数据并检查用户和通行证是否与ThextBox文本相同。

protected void Button1_Click(object sender, EventArgs e)
{
    try
    {
        String sCon = "SERVER=localhost;DATABASE=sd_tema1;UID=root;";
        MySqlConnection con = new MySqlConnection(sCon);

        if (CheckUserLogin(Label2.Text, Label3.Text))
        {
            Response.Redirect("login.aspx");
        } 

    }
    catch (Exception ex)
    {
        Label1.Text = ex.ToString();
    }
}

public Boolean CheckUserLogin(string username, string password)
{
    try
    {
        String sCon = "SERVER=localhost;DATABASE=sd_tema1;UID=root;";
        MySqlConnection con = new MySqlConnection(sCon);

        String query = "Select * from users where username= ?userName and password= ?passWord";
        MySqlCommand cmd = new MySqlCommand(query,con);
        cmd.Parameters.Add("?userName", TextBox1.Text);
        cmd.Parameters.Add("?passWord", TextBox2.Text);
        cmd.Prepare();
        MySqlDataReader print = cmd.ExecuteReader();
        bool read = print.Read();
        if(username.Equals(print.GetString("1")) && password.Equals(print.GetString("2"))) return true;
    }
    catch (Exception ex)
    {
        Label1.Text = ex.ToString();
    }
    return false;
}

Answer 1

在调用ExecuteReader方法之前，您没有打开连接。致电con.Open。您的问题将得到解决。

ASP.NET Mysql数据读取器无法正常工作

1 个答案: