winform登陆后关闭登录窗口跳转到主窗体

private void btn_submit_Click(object sender, EventArgs e)

        {

            try

            {

                SqlConnection con = new ConnectSQL().getSQLCon();

                string sql = "select * from userinfo where username='" + this.txt_NserName.Text + "'";

                SqlCommand cmd = new SqlCommand(sql, con);

                con.Open();

                SqlDataReader dr = cmd.ExecuteReader();

                if (dr.Read())

                {

                    if (dr["password"].ToString() == this.txt_pwd.Text)

                    {

                        //MainForm mainform = new MainForm();

                        //UserInfo user = new UserInfo();

                        UserInfo.email = dr["email"].ToString();

                        UserInfo.nickname = dr["nickname"].ToString();

                        UserInfo.state = dr["state"].ToString();

                        UserInfo.username = dr["username"].ToString();

                        UserInfo.userimage = dr["userimage"].ToString();

                        UserInfo.uid = int.Parse(dr["uid"].ToString());

                        //mainform.user = user;

                        this.DialogResult = DialogResult.OK;

                        //this.Close();

                        //this.Visible = false;

                       // mainform.Show();

                    }

                    else

                    {

                        MessageBox.Show("密码错误!");

                    }

                    dr.Dispose();

                    con.Close();

                }

                else

                {

                    if (this.txt_NserName.Text == "")

                    {

                        MessageBox.Show("请输入信息");

                    }

                    else

                    {

                        MessageBox.Show("该用户名不存在");

                    }

                    dr.Dispose();

                    con.Close();

                }

            }

            catch (Exception ex)

            {

                MessageBox.Show("点击按钮事件异常：/n"+ex.ToString()

 

以上代码是登录按钮的事件

对于登录后怎么关闭的登录窗口的代码如下，其中要注明的是userinfo是个静态类，用来存储用户的信息，以带到主窗体中去

上述代码可以根据自己情况而定，关键是要传入一个参数：this.DialogResult = DialogResult.OK;

 

下面代码写在程序Program.cs里

        [STAThread]

        static void Main()

        {

            Application.EnableVisualStyles();

            Application.SetCompatibleTextRenderingDefault(false);

           

            LoginForm login = new LoginForm();

            login.ShowDialog();

            if (login.DialogResult == DialogResult.OK)

            {

                Application.Run(new MainForm());

            }

        }