/*UpdateDelForm.aspx.cs

后臺程序代碼

*/

using System;
using System.Collections;
using System.ComponentModel;
using System.Data;
using System.Data.SqlClient;
using System.Drawing;
using System.Web;
using System.Web.SessionState;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.HtmlControls;

namespace UpdateDelDbDemo
{
 /// <summary>
 /// WebForm1 的摘要說明。
 /// </summary>
 public class UpdateDelForm : System.Web.UI.Page
 {
  protected System.Web.UI.WebControls.DataGrid dgDemo;
  private string strCon="server=JOSEN;database=testDb;integrated security=true";
  private string strSqlSelect="select * from UserInfo";
  private SqlConnection objCon;
 
  private void Page_Load(object sender, System.EventArgs e)
  {
   // 在此處放置用戶代碼以初始化頁面
   if(!IsPostBack)
    LoadGrid();
  }

  #region Web 窗體設計器生成的代碼
  override protected void OnInit(EventArgs e)
  {
   //
   // CODEGEN: 該調用是 ASP.NET Web 窗體設計器所必需的。
   //
   InitializeComponent();
   base.OnInit(e);
  }
  
  /// <summary>
  /// 設計器支持所需的方法 - 不要使用代碼編輯器修改
  /// 此方法的內容。
  /// </summary>
  private void InitializeComponent()
  {   
   this.dgDemo.CancelCommand += new System.Web.UI.WebControls.DataGridCommandEventHandler(this.dgDemo_CancelCommand);
   this.dgDemo.EditCommand += new System.Web.UI.WebControls.DataGridCommandEventHandler(this.dgDemo_EditCommand);
   this.dgDemo.UpdateCommand += new System.Web.UI.WebControls.DataGridCommandEventHandler(this.dgDemo_UpdateCommand);
   this.dgDemo.DeleteCommand += new System.Web.UI.WebControls.DataGridCommandEventHandler(this.dgDemo_DeleteCommand);
   this.Load += new System.EventHandler(this.Page_Load);

  }
  #endregion
  //讀取數據并幫定到ＤａｔａＧｒｉｄ
  private void LoadGrid()
  {
   Connect();
   SqlDataAdapter objAdpt=new SqlDataAdapter(strSqlSelect,objCon);
   DataSet ds=new DataSet();
   objAdpt.Fill(ds,"dtUserInfo");

   dgDemo.DataSource=ds;
   dgDemo.DataBind();
  }
  //建立數據庫的連接
  private void Connect()
  {
   if(objCon==null)
    objCon=new SqlConnection(strCon);
   if(objCon.State==ConnectionState.Closed)
    objCon.Open();
  
  }
  //斷開數據庫的連接
  private void Disconnect()
  {
   objCon.Close();
  }

  private void dgDemo_EditCommand(object source, System.Web.UI.WebControls.DataGridCommandEventArgs e)
  {
   dgDemo.EditItemIndex=e.Item.ItemIndex;
   LoadGrid();
  }

  private void dgDemo_CancelCommand(object source, System.Web.UI.WebControls.DataGridCommandEventArgs e)
  {
   dgDemo.EditItemIndex=-1;
   LoadGrid();
  }

  private void dgDemo_UpdateCommand(object source, System.Web.UI.WebControls.DataGridCommandEventArgs e)
  {
   string strUserID=e.Item.Cells[0].Text;
   //string strUserID=((TextBox)e.Item.Cells[0].Controls[0]).Text;
   string strFirstName=((TextBox)e.Item.Cells[1].Controls[0]).Text;
   string strLastName=((TextBox)e.Item.Cells[2].Controls[0]).Text;
   string strAddress=((TextBox)e.Item.Cells[3].Controls[0]).Text;

   dgDemo.EditItemIndex=-1;
   //此方法具體處理數據庫的更新
   UpdateRecord(strUserID,strFirstName,strLastName,strAddress);
   //調用此方法從數據庫讀取數據
   LoadGrid();

  }

  private void UpdateRecord(string strUserID, string strFirstName, string strLastName, string strAddress)
  {
   Connect();
   SqlDataAdapter objAdpt=new SqlDataAdapter(strSqlSelect,objCon);
   DataSet ds=new DataSet();
   objAdpt.Fill(ds,"dtUserInfo");
   Disconnect();

   DataTable tbl=ds.Tables["dtUserInfo"];
   
   //設定表的主鍵
   DataColumn[] myKey=new DataColumn[1];
   myKey[0]=tbl.Columns["ID"];
   tbl.PrimaryKey=myKey;
   
   DataRow dr=tbl.Rows.Find(strUserID);
   //dr["ID"]=strUserID;
   dr["FirstName"]=strFirstName;
   dr["LastName"]=strLastName;
   dr["address"]=strAddress;

   SqlCommandBuilder cb=new SqlCommandBuilder(objAdpt);
   Connect();
   objAdpt.Update(ds,"dtUserInfo");
   Disconnect();
  }

  private void dgDemo_DeleteCommand(object source, System.Web.UI.WebControls.DataGridCommandEventArgs e)
  {

   string strUserID=e.Item.Cells[0].Text;

   dgDemo.EditItemIndex=-1;
   DelRecord(strUserID);
   //調用此方法從數據庫讀取數據
   LoadGrid();
  }
  private void DelRecord(string strUserID)
  {
   Connect();
   SqlDataAdapter objAdpt=new SqlDataAdapter(strSqlSelect,objCon);
   DataSet ds=new DataSet();
   objAdpt.Fill(ds,"dtUserInfo");
   Disconnect();

   DataTable tbl=ds.Tables["dtUserInfo"];
   
   //設定表的主鍵
   DataColumn[] myKey=new DataColumn[1];
   myKey[0]=tbl.Columns["ID"];
   tbl.PrimaryKey=myKey;
   
   DataRow dr=tbl.Rows.Find(strUserID);
   dr.Delete();