C#下WinForm编程：登录窗体的设计

我在csdn里搜索了很久，也没有找到符合我要求的login文档，我这次把自己的心得和自己做的成果拿出来和大家分享一下，希望对后来的人能有一些帮助。我初次做，可能代码写的不是很规范，思路也不是很清晰，但是它能达到我要的效果就行了^_^      希望哪位兄弟帮忙完善一下我的代码。

我在数据库里有一个   users  的表，如下：

ID     UserName           UserPasswd

1        admin                    admin

2        user                        user

3        guest                     guest

我准备这样做，先判断输入的用户名是否和表里的UserName相同，如果相同，再比较相同UserName下的UserPasswd，如果这些都正确了，就可以进入系统了。

全部代码如下（我把我写的部分用黑体）：

Form1的代码：

using System;
using System.Drawing;
using System.Collections;
using System.ComponentModel;
using System.Windows.Forms;
using System.Data;
using System.Data.SqlClient;

namespace login
{
 /// <summary>
 /// Form1 的摘要说明。
 /// </summary>
 public class Form1 : System.Windows.Forms.Form
 {
  private System.Windows.Forms.Label label1;
  private System.Windows.Forms.Label label2;
  private System.Windows.Forms.TextBox txtUser;
  private System.Windows.Forms.TextBox txtPasswd;
  private System.Windows.Forms.Button btnOK;
  private System.Windows.Forms.Button btnCancel;
  /// <summary>
  /// 必需的设计器变量。
  /// </summary>
  private System.ComponentModel.Container components = null;

  public Form1()
  {
   //
   // Windows 窗体设计器支持所必需的
   //
   InitializeComponent();

   
   //
   // TODO: 在 InitializeComponent 调用后添加任何构造函数代码
   //
  }

  /// <summary>
  /// 清理所有正在使用的资源。
  /// </summary>
  protected override void Dispose( bool disposing )
  {
   if( disposing )
   {
    if (components != null)
    {
     components.Dispose();
    }
   }
   base.Dispose( disposing );
  }

  #region Windows 窗体设计器生成的代码
  /// <summary>
  /// 设计器支持所需的方法 - 不要使用代码编辑器修改
  /// 此方法的内容。
  /// </summary>
  private void InitializeComponent()
  {
   this.label1 = new System.Windows.Forms.Label();
   this.label2 = new System.Windows.Forms.Label();
   this.txtUser = new System.Windows.Forms.TextBox();
   this.txtPasswd = new System.Windows.Forms.TextBox();
   this.btnOK = new System.Windows.Forms.Button();
   this.btnCancel = new System.Windows.Forms.Button();
   this.SuspendLayout();
   //
   // label1
   //
   this.label1.Font = new System.Drawing.Font("宋体", 10.5F, System.Drawing.FontStyle.Bold, System.Drawing.GraphicsUnit.Point, ((System.Byte)(134)));
   this.label1.Location = new System.Drawing.Point(40, 24);
   this.label1.Name = "label1";
   this.label1.Size = new System.Drawing.Size(64, 23);
   this.label1.TabIndex = 0;
   this.label1.Text = "用户名：";
   //
   // label2
   //
   this.label2.Font = new System.Drawing.Font("宋体", 10.5F, System.Drawing.FontStyle.Bold, System.Drawing.GraphicsUnit.Point, ((System.Byte)(134)));
   this.label2.Location = new System.Drawing.Point(40, 72);
   this.label2.Name = "label2";
   this.label2.Size = new System.Drawing.Size(56, 23);
   this.label2.TabIndex = 1;
   this.label2.Text = "密码：";
   //
   // txtUser
   //
   this.txtUser.Location = new System.Drawing.Point(152, 24);
   this.txtUser.Name = "txtUser";
   this.txtUser.TabIndex = 2;
   this.txtUser.Text = "";
   //
   // txtPasswd
   //
   this.txtPasswd.Location = new System.Drawing.Point(152, 72);
   this.txtPasswd.Name = "txtPasswd";
   this.txtPasswd.PasswordChar = '*';
   this.txtPasswd.TabIndex = 3;
   this.txtPasswd.Text = "";
   //
   // btnOK
   //
   this.btnOK.Location = new System.Drawing.Point(40, 120);
   this.btnOK.Name = "btnOK";
   this.btnOK.Size = new System.Drawing.Size(72, 23);
   this.btnOK.TabIndex = 4;
   this.btnOK.Text = "OK";
   this.btnOK.Click += new System.EventHandler(this.btnOK_Click);
   //
   // btnCancel
   //
   this.btnCancel.DialogResult = System.Windows.Forms.DialogResult.Cancel;
   this.btnCancel.Location = new System.Drawing.Point(176, 120);
   this.btnCancel.Name = "btnCancel";
   this.btnCancel.TabIndex = 5;
   this.btnCancel.Text = "Cancel";
   this.btnCancel.Click += new System.EventHandler(this.btnCancel_Click);
   //
   // Form1
   //
   this.AcceptButton = this.btnOK;
   this.AutoScaleBaseSize = new System.Drawing.Size(6, 14);
   this.CancelButton = this.btnCancel;
   this.ClientSize = new System.Drawing.Size(298, 167);
   this.Controls.Add(this.btnCancel);
   this.Controls.Add(this.btnOK);
   this.Controls.Add(this.txtPasswd);
   this.Controls.Add(this.txtUser);
   this.Controls.Add(this.label2);
   this.Controls.Add(this.label1);
   this.FormBorderStyle = System.Windows.Forms.FormBorderStyle.FixedDialog;
   this.MaximizeBox = false;
   this.MaximumSize = new System.Drawing.Size(304, 192);
   this.MinimizeBox = false;
   this.MinimumSize = new System.Drawing.Size(304, 192);
   this.Name = "Form1";
   this.ShowInTaskbar = false;
   this.Text = "Login";
   this.Load += new System.EventHandler(this.Form1_Load);
   this.ResumeLayout(false);

  }
  #endregion

  /// <summary>
  /// 应用程序的主入口点。
  /// </summary>

  private void btnCancel_Click(object sender, System.EventArgs e)
  {
   Application.Exit();
  }

  private void Form1_Load(object sender, System.EventArgs e)
  {
   this.SetDesktopLocation(280,180);

   
  }

  private void btnOK_Click(object sender, System.EventArgs e)
  {
   
   Form2 theOwner = (Form2)this.Owner;

   if(this.txtUser.Text == "")
   {
    MessageBox.Show("用户名不能为空！","错误");
   }
   else if(this.txtPasswd.Text == "")
   {
    MessageBox.Show("密码不能为空！","错误");
   }
   else
   {
    if(IsUser(this.txtUser.Text))
    {
     if(this.txtPasswd.Text == LoginUser(this.txtUser.Text))
     {
      this.DialogResult = DialogResult.OK;
      theOwner.getUserName = this.txtUser.Text;
     }
     else
     {
      MessageBox.Show("用户名或密码错误！");
     }
    }
    else
    {
     MessageBox.Show("用户名或密码错误！");
    }
   }
   
   
  }
  private string LoginUser(string User)
  {
   SqlConnection conn = new SqlConnection("XXXXXXXX");
   SqlCommand cmd = new SqlCommand();
   cmd.CommandType = CommandType.StoredProcedure;
   cmd.CommandText = "Login";
   cmd.Connection = conn;
   conn.Open();
   
   SqlParameter parName = new SqlParameter("@Name",SqlDbType.VarChar,50);
   parName.Value = User;
   cmd.Parameters.Add(parName);

   cmd.ExecuteNonQuery();
   
   conn.Close();
   SqlDataAdapter da = new SqlDataAdapter();
   da.SelectCommand = cmd;
   DataSet ds = new DataSet();
   da.Fill(ds);

   return ds.Tables[0].Rows[0]["UserPasswd"].ToString();
  }
  private bool IsUser(string User)
  {
   SqlConnection conn = new SqlConnection("XXXXXXXX");
   SqlCommand cmd = new SqlCommand();
   cmd.CommandType = CommandType.StoredProcedure;
   cmd.CommandText = "IsUser";
   cmd.Connection = conn;
   conn.Open();
   
   SqlParameter parName = new SqlParameter("@UserName",SqlDbType.VarChar,50);
   parName.Value = User;
   cmd.Parameters.Add(parName);

   cmd.ExecuteNonQuery();
   
   conn.Close();
   SqlDataAdapter da = new SqlDataAdapter();
   da.SelectCommand = cmd;
   DataSet ds = new DataSet();
   da.Fill(ds);

   int n;
   n = ds.Tables[0].Rows.Count;
   if(n > 0)
    return true;
   else
    return false;
  }
 }
}

在Form2中我设计了一个label ，让它接受从Form1传过来的UserName，这样我们在以后的设计中好判断用户的权限的大小。

Form2的代码：

using System;
using System.Drawing;
using System.Collections;
using System.ComponentModel;
using System.Windows.Forms;
using System.Data;
using System.Data.SqlClient;

namespace login
{
 /// <summary>
 /// Form2 的摘要说明。
 /// </summary>
 public class Form2 : System.Windows.Forms.Form
 {
  private string UserName;
  private System.Windows.Forms.Label label1;
  /// <summary>
  /// 必需的设计器变量。
  /// </summary>
  private System.ComponentModel.Container components = null;

  public Form2()
  {
   //
   // Windows 窗体设计器支持所必需的
   //
   InitializeComponent();
   Form1 myForm = new Form1();
   myForm.ShowDialog(this);

   //
   // TODO: 在 InitializeComponent 调用后添加任何构造函数代码
   //
  }

  /// <summary>
  /// 清理所有正在使用的资源。
  /// </summary>
  protected override void Dispose( bool disposing )
  {
   if( disposing )
   {
    if(components != null)
    {
     components.Dispose();
    }
   }
   base.Dispose( disposing );
  }

  #region Windows 窗体设计器生成的代码
  /// <summary>
  /// 设计器支持所需的方法 - 不要使用代码编辑器修改
  /// 此方法的内容。
  /// </summary>
  private void InitializeComponent()
  {
   this.label1 = new System.Windows.Forms.Label();
   this.SuspendLayout();
   //
   // label1
   //
   this.label1.Location = new System.Drawing.Point(128, 72);
   this.label1.Name = "label1";
   this.label1.Size = new System.Drawing.Size(152, 40);
   this.label1.TabIndex = 0;
   //
   // Form2
   //
   this.AutoScaleBaseSize = new System.Drawing.Size(6, 14);
   this.ClientSize = new System.Drawing.Size(520, 357);
   this.Controls.Add(this.label1);
   this.Name = "Form2";
   this.Text = "Form2";
   this.Load += new System.EventHandler(this.Form2_Load);
   this.ResumeLayout(false);

  }
  #endregion
  [STAThread]
  static void Main()
  {
   Application.Run(new Form2());
  }

  private void Form2_Load(object sender, System.EventArgs e)
  {
   this.SetDesktopLocation(200,180);
   this.label1.Text = UserName;
  }
  public string getUserName
  {
   get
   {
    return UserName;
   }
   set
   {
    UserName = value;
   }
  }
 }
}