formlogin.cs

我在学习移动设备开发时

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

using System.Data;
using System.Data.Common;
using System.Data.SqlServerCe;
using System.Data.SqlTypes;

namespace WinCE_DBF
{
	/// <summary>
	/// FormLogIn 的摘要说明。
	/// </summary>
	public class FormLogIn : System.Windows.Forms.Form
	{
		private System.Windows.Forms.Label label1;
		private System.Windows.Forms.Label label2;
		private System.Windows.Forms.TextBox textBox1;
		private System.Windows.Forms.Button btLogin;
		private System.Windows.Forms.Button btCancel;
		private System.Windows.Forms.TextBox textBox2;
	
        public string UName; //用户名

		public FormLogIn()
		{
			//
			// 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 )
		{
			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.textBox1 = new System.Windows.Forms.TextBox();
			this.textBox2 = new System.Windows.Forms.TextBox();
			this.btLogin = new System.Windows.Forms.Button();
			this.btCancel = new System.Windows.Forms.Button();
			// 
			// label1
			// 
			this.label1.Font = new System.Drawing.Font("宋体", 12F, System.Drawing.FontStyle.Bold);
			this.label1.ForeColor = System.Drawing.SystemColors.HotTrack;
			this.label1.Location = new System.Drawing.Point(9, 12);
			this.label1.Size = new System.Drawing.Size(80, 16);
			this.label1.Text = "UserName:";
			// 
			// label2
			// 
			this.label2.Font = new System.Drawing.Font("宋体", 12F, System.Drawing.FontStyle.Bold);
			this.label2.ForeColor = System.Drawing.SystemColors.HotTrack;
			this.label2.Location = new System.Drawing.Point(9, 44);
			this.label2.Size = new System.Drawing.Size(80, 20);
			this.label2.Text = "PassWord:";
			// 
			// textBox1
			// 
			this.textBox1.Location = new System.Drawing.Point(97, 11);
			this.textBox1.MaxLength = 10;
			this.textBox1.Size = new System.Drawing.Size(135, 21);
			this.textBox1.Text = "";
			this.textBox1.KeyPress += new System.Windows.Forms.KeyPressEventHandler(this.textBox1_KeyPress);
			// 
			// textBox2
			// 
			this.textBox2.Location = new System.Drawing.Point(97, 44);
			this.textBox2.MaxLength = 10;
			this.textBox2.PasswordChar = '*';
			this.textBox2.Size = new System.Drawing.Size(135, 21);
			this.textBox2.Text = "";
			this.textBox2.KeyPress += new System.Windows.Forms.KeyPressEventHandler(this.textBox2_KeyPress);
			// 
			// btLogin
			// 
			this.btLogin.Location = new System.Drawing.Point(32, 88);
			this.btLogin.Text = "LogIn";
			this.btLogin.Click += new System.EventHandler(this.btLogin_Click);
			// 
			// btCancel
			// 
			this.btCancel.Location = new System.Drawing.Point(136, 88);
			this.btCancel.Text = "Cancel";
			this.btCancel.Click += new System.EventHandler(this.btCancel_Click);
			// 
			// FormLogIn
			// 
			this.ClientSize = new System.Drawing.Size(242, 127);
			this.Controls.Add(this.btCancel);
			this.Controls.Add(this.btLogin);
			this.Controls.Add(this.textBox2);
			this.Controls.Add(this.textBox1);
			this.Controls.Add(this.label2);
			this.Controls.Add(this.label1);
			this.MaximizeBox = false;
			this.MinimizeBox = false;
			this.Text = "FormLogIn";
			this.Load += new System.EventHandler(this.FormLogIn_Load);

		}
		#endregion

		private void FormLogIn_Load(object sender, System.EventArgs e)
		{
		    UName="";
			this.Left=200;
			this.Top=35;
			this.textBox1.Focus();
		}
        
		private void LogIn()
		{
			//系统登录的实现部分
			this.UName="";
			if(this.textBox1.Text.Trim()=="")
			{
				MessageBox.Show("Please Input UserName!");
				this.textBox1.Focus();
				return;
			}
			if(this.textBox2.Text.Trim()=="")
			{
				MessageBox.Show("Please Input PassWord!");
				this.textBox2.Focus();
				return;
			}
			SqlCeConnection conn = null;
			conn = new SqlCeConnection ("Data Source =SqlCeDB.sdf");
			if(conn.State==ConnectionState.Closed)
				conn.Open();
			//conn.Open();
			SqlCeCommand cmd = conn.CreateCommand();
			cmd.CommandText = "SELECT * FROM pass"; 
			//cmd.CommandText = "SELECT * FROM pass where USERR= ?"; 
			//cmd.Parameters.Add(new SqlCeParameter("p1", SqlDbType.NText));
			//cmd.Parameters["p1"].Size = 10;
			//cmd.Parameters["p1"].Value=this.textBox1.Text.Trim();
			SqlCeDataReader rdr = cmd.ExecuteReader();
			while(rdr.Read())
			{
				if ((this.textBox1.Text.Trim()==rdr.GetString(0))&&(this.textBox2.Text.Trim()==rdr.GetString(1)))
				{
					this.UName=this.textBox1.Text.Trim();
					rdr.Close();
					break;
				}
			}
			cmd.Parameters.Clear();
			if (this.UName=="")
			{
				MessageBox.Show("UserName or PassWord Errror!");
				conn.Close();
				this.textBox1.Text="";
				this.textBox2.Text="";
				this.textBox1.Focus();
				return;
			}
			else
				this.DialogResult=DialogResult.OK;
			if(conn.State==ConnectionState.Open)
				conn.Close();
			this.Close();
		}

		private void btLogin_Click(object sender, System.EventArgs e)
		{
		    //系统登录
            LogIn();
		}

		private void btCancel_Click(object sender, System.EventArgs e)
		{
		    //取消登录
			this.DialogResult=DialogResult.Cancel;
			this.Close();
		}

		private void textBox1_KeyPress(object sender, System.Windows.Forms.KeyPressEventArgs e)
		{
			if(e.KeyChar==13)
			   LogIn();	
		}

		private void textBox2_KeyPress(object sender, System.Windows.Forms.KeyPressEventArgs e)
		{
			if(e.KeyChar==13)
			   LogIn();
		}
	}
}