如何用C#编写用户登陆界面

Question

请问如何用C#编写用户登陆界面,最好带一个简单的示例。谢谢！

Answer 1

?C/S?B/S?
2个文本框输入用户名秘密，在BUTTON下查询两个输入结果，与数据库相应的字段匹配，如果匹配，。如果不匹配，提示错误，文本清空

Answer 2

可参考：http://www.cnblogs.com/KissKnife/archive/2006/09/10/500158.html

Answer 3

if (txtUser.Text == "" || txtPassword.Text == "")
            {
                MessageBox.Show("请输入用户名和密码", "提示", MessageBoxButtons.OK, MessageBoxIcon.Information);
            }
            else 
            {
                try
                {
                    myConnection = new SqlConnection(Login.Connection);
                    SqlCommand myCommand = myConnection.CreateCommand();
                    myCommand.CommandText = "SELECT UserSort " +
                                            "From Users " +
                                            "Where UserID = '" + txtUser.Text +
                                            "' And UserPassword = '" + txtPassword.Text + "'";
                    myConnection.Open();
                    Sort = myCommand.ExecuteReader();
                    try
                    {
                        Sort.Read();
                        //如果由返回的项得到 “System”，则弹出完整功能界面
                        if (Sort.GetString(0) == "System")
                        {
                            this.Hide();
                            MMForm.ManageForm myMF = new MMForm.ManageForm(true);
                            myMF.ShowDialog();
                            this.Close();    //在主功能界面退出后同时关闭登录界面
                        }
                        //如果由返回的项得到 "User" ，则屏蔽用户信息维护功能
                        if (Sort.GetString(0) == "User")
                        {
                            this.Hide();
                            MMForm.ManageForm myMF = new MMForm.ManageForm(false);
                            myMF.ShowDialog();
                            this.Close();       //在主功能界面退出后同时关闭登录界面
                        }
                    }
                    catch
                    {
                        MessageBox.Show("请输入正确的用户名和密码！！！","提示",MessageBoxButtons.OK,MessageBoxIcon.Warning);
                    }
                }
                catch (SqlException ex)
                {
                    MessageBox.Show("连接数据库错误：" + ex.Message, "警告", MessageBoxButtons.OK, MessageBoxIcon.Error);
                }
                catch (Exception ex)
                {
                    MessageBox.Show(ex.Message);
                }
                finally
                {
                    myConnection.Close();   //释放数据库连接
                }

Answer 4

if (txtUser.Text == "" || txtPassword.Text == "")
            {
                MessageBox.Show("请输入用户名和密码", "提示", MessageBoxButtons.OK, MessageBoxIcon.Information);
            }
            else 
            {
                try
                {
                    myConnection = new SqlConnection(Login.Connection);
                    SqlCommand myCommand = myConnection.CreateCommand();
                    myCommand.CommandText = "SELECT UserSort " +
                                            "From Users " +
                                            "Where UserID = '" + txtUser.Text +
                                            "' And UserPassword = '" + txtPassword.Text + "'";
                    myConnection.Open();
                    Sort = myCommand.ExecuteReader();
                    try
                    {
                        Sort.Read();
                        //如果由返回的项得到 “System”，则弹出完整功能界面
                        if (Sort.GetString(0) == "System")
                        {
                            this.Hide();
                            MMForm.ManageForm myMF = new MMForm.ManageForm(true);
                            myMF.ShowDialog();
                            this.Close();    //在主功能界面退出后同时关闭登录界面
                        }
                        //如果由返回的项得到 "User" ，则屏蔽用户信息维护功能
                        if (Sort.GetString(0) == "User")
                        {
                            this.Hide();
                            MMForm.ManageForm myMF = new MMForm.ManageForm(false);
                            myMF.ShowDialog();
                            this.Close();       //在主功能界面退出后同时关闭登录界面
                        }
                    }
                    catch
                    {
                        MessageBox.Show("请输入正确的用户名和密码！！！","提示",MessageBoxButtons.OK,MessageBoxIcon.Warning);
                    }
                }
                catch (SqlException ex)
                {
                    MessageBox.Show("连接数据库错误：" + ex.Message, "警告", MessageBoxButtons.OK, MessageBoxIcon.Error);
                }
                catch (Exception ex)
                {
                    MessageBox.Show(ex.Message);
                }
                finally
                {
                    myConnection.Close();   //释放数据库连接
                }