frmusersearch.cs

本论文叙述了联机考试系统的现状以及C#语言的概况。重点介绍了联机考试系统的实现过程：包括系统分析、 系统调查、 数据流程分析、功能设计、 数据库设计、 系统物理配置方案、 系统实现、 系统测试和调试。

			this.pdocUser.PrintPage += new System.Drawing.Printing.PrintPageEventHandler(this.pdocUser_PrintPage);
			// 
			// pdlgUser
			// 
			this.pdlgUser.Document = this.pdocUser;
			// 
			// frmUserSearch
			// 
			this.AutoScaleBaseSize = new System.Drawing.Size(6, 14);
			this.BackgroundImage = ((System.Drawing.Image)(resources.GetObject("$this.BackgroundImage")));
			this.ClientSize = new System.Drawing.Size(783, 520);
			this.ControlBox = false;
			this.Controls.Add(this.btnSave);
			this.Controls.Add(this.btnHelp);
			this.Controls.Add(this.btnClose);
			this.Controls.Add(this.dbgUserDetails);
			this.Controls.Add(this.cboStatus);
			this.Controls.Add(this.cboUserType);
			this.Controls.Add(this.txtUserName);
			this.Controls.Add(this.lblHeading);
			this.Controls.Add(this.btnPrint);
			this.Controls.Add(this.btnSearch);
			this.Controls.Add(this.lblUserType);
			this.Controls.Add(this.lblUserName);
			this.Controls.Add(this.lblStatus);
			this.Controls.Add(this.grpSearch);
			this.FormBorderStyle = System.Windows.Forms.FormBorderStyle.None;
			this.Location = new System.Drawing.Point(146, 115);
			this.Name = "frmUserSearch";
			this.ShowInTaskbar = false;
			this.StartPosition = System.Windows.Forms.FormStartPosition.Manual;
			this.Text = "frmUserSearch";
			this.TopMost = true;
			this.Load += new System.EventHandler(this.frmUserSearch_Load);
			this.Paint += new System.Windows.Forms.PaintEventHandler(this.frmUserSearch_Paint);
			((System.ComponentModel.ISupportInitialize)(this.dbgUserDetails)).EndInit();
			this.ResumeLayout(false);

		}
		#endregion

		private void dbgUserDetails_DoubleClick(object sender, System.EventArgs e)
		{
			try
			{
				//如果是第一次进入则DataGrid的Visible 设为false
				if(this.index ==0)
				{
					return;
				}
				
				index++;
				this.Hide();
				dtUser =(DataTable)dbgUserDetails.DataSource; 			     
				DataRow drUser = dtUser.Rows[dbgUserDetails.CurrentRowIndex];
				this.userid = drUser[1].ToString();		
	
				//set flag as 3 for opening the frmUser form in the modify mode
				//				frmUser user=new frmUser(3,this,this.userid);
				frmUser user=new frmUser(3,this,this.dbgUserDetails .CurrentCell .RowNumber ,this.dtBefore );
			
				if ((index==1) && (frmUser.dtUpdate!=null))
				{
					frmUser.dtUpdate.Clear();
				}
			
				user.Show();
			}
			catch(Exception excep)
			{
				MessageBox.Show(excep.Message.ToString ());
				MessageBox.Show(excep.StackTrace.ToString ());
			}
		}

		private void btnClose_Click(object sender, System.EventArgs e)
		{
			updateflag=false;
			this.Close();
		}

		private void frmUserSearch_Paint(object sender, System.Windows.Forms.PaintEventArgs e)
		{
			
			if(updateflag)
			{
				this.btnSave .Enabled =true;
			}
		}
		private void btnSave_Click(object sender, System.EventArgs e)
		{
			try
			{
				DataAccess objDA = DataAccess.GetInstance ();
				
				//to know whether updation was performed or no updation 
				//was performed in the other form, we check the 
				//rowUpdated array contents. This array contains a set 
				//of true and false values where true will indicate 
				//that row has been modified
				bool updated=false;
				for (int index = 0;index < rowUpdated.Length;index++)
				{
					if (rowUpdated[index])
						updated=true;
				}

				if (updated)
				{

					//create an instance of user class and 
					//invoke its UpdateRecords method, 
					//pass to it the data table containing the 
					//set of modified records
				
					User objUser = new User();
					objUser.UpdateRecords(frmUser.dtUpdate);
			    
					//after updation, refresh the datagrid by retrieving records again
					doSearch();	
					MessageBox.Show ("已成功更新用户详细信息");
				}
				else
				{
					MessageBox.Show ("未检测到对用户详细信息所作的修改");
				}

				this.btnClose.Enabled =true;
				this.btnSave .Enabled =false;
			
			}
			catch(Exception excep)
			{
				MessageBox.Show ("出现异常"+excep.StackTrace.ToString ());
			}
				
		}

		private void btnSearch_Click(object sender, System.EventArgs e)
		{
			doSearch();
			//查询一次加1，启动DataGrid的双击事件
			this.index ++;
			//store the fetched records into another table
			dtBefore = (DataTable)this.dbgUserDetails.DataSource;
		}

		private void cboStatus_SelectedIndexChanged(object sender, System.EventArgs e)
		{
			if (this.cboStatus.Text.Equals ("Active"))
				this.status=true;
			else
				this.status=false;
		}

		private void frmUserSearch_Load(object sender, System.EventArgs e)
		{
			this.btnSave .Enabled =false;
			this.cboStatus.Text ="Active";
			this.status = true;
			if (updateflag) //check if update was performed in the frmUser form and data was modified there
			{
				
				//if yes, 
				//then enable Save button in this form               
				this.btnSave.Enabled =true;	
				//绑定已经frmUser窗体中修改过的表dtUpdate
				this.dbgUserDetails.DataSource=frmUser.dtUpdate;//dtBefore;
				
			}
			this.Focus ();
			
		}
	
 
		private void doSearch()
		{
			try
			{
				if(this.txtUserName.Text != "") //if username is not null
				{
					searchValue[0] =  this.txtUserName.Text;
				}
				else
				{
					searchValue[0] =  "";
				}
				if(this.cboUserType.Text != "") //if usertype is not null
				{
					searchValue[1] =  this.cboUserType.Text;
				}
				else if(this.cboUserType.Text == "") //if usertype is null
				{
					searchValue[1] =  "";
				}
				if(this.cboStatus.Text != "") //if status is not null
				{
					searchValue[2] =  this.status.ToString();  
				}
				else
				{
					searchValue[2] = "" ;
				}
				//create an instance of user class and invoke the 
				//method to fetch the records based on given criteria
				DataAccess objDA=DataAccess.GetInstance ();
				User objUser = new User();
				searchValue[3]="";
				DataTable dtUser = objUser.FetchRecords(searchValue);
             
							
				//populate the datagrid with the fetched data
				this.dbgUserDetails.DataSource = dtUser;

				//based on the number of rows in the datagrid, create
				// an array of boolean values
				
				if (rowUpdated==null)
					rowUpdated = new bool[dtUser.Rows.Count]; 	
			}
			catch(Exception myException)
			{
				Console.WriteLine(myException.Message);
			}
		}

		private void btnPrint_Click(object sender, System.EventArgs e)
		{
			try
			{
				if (pdlgUser.ShowDialog() == DialogResult.OK)
				{
					pdocUser.Print();
				}
			}
			catch(Exception excep)
			{
				MessageBox.Show("打印时出错。" +excep.Message.ToString());
			}
		}
		

		private void pdocUser_PrintPage(object sender, System.Drawing.Printing.PrintPageEventArgs e)
		{
			try
			{
				DataTable dt=(DataTable)this.dbgUserDetails.DataSource; 
				Datagridprinter objDGP = new Datagridprinter(this.dbgUserDetails, pdocUser,dt);
				objDGP.PageNumber = 1;
				objDGP.RowCount = 0;

				Graphics	g = e.Graphics;
				
				bool more = objDGP.DrawDataGrid(g);
				if (more == true)
				{
					e.HasMorePages = true;
					objDGP.PageNumber++;
				}
			}
		
			catch(Exception excep)
			{
				MessageBox.Show("打印时出错。" +excep.Message.ToString());
			}
		}

		private void btnHelp_Click(object sender, System.EventArgs e)
		{
			Help.ShowHelp(this,Environment.CurrentDirectory +@"\\OES_Help\OES_Help.chm");
		}
	}
}