category.aspx.cs

来自「数字图书馆网站」· CS 代码 · 共 258 行

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

namespace DigitalLibrary
{
	/// <summary>
	/// Summary description for Category.
	/// </summary>
	public class Category : System.Web.UI.Page
	{
		protected System.Web.UI.WebControls.Label lblTitle;
		protected System.Web.UI.WebControls.TextBox txtCatDesc;
		protected System.Web.UI.WebControls.TextBox txtCategory;
		protected System.Web.UI.WebControls.Panel pnlCategory;
		protected System.Web.UI.WebControls.Label lblCategory;
		protected System.Web.UI.WebControls.LinkButton lbUpdate;
		protected System.Web.UI.WebControls.LinkButton lbCancel;
		protected System.Web.UI.WebControls.Label lblMessage;
		protected System.Web.UI.WebControls.Button btnAdd;
		protected System.Web.UI.WebControls.Button btnBack;
		protected System.Web.UI.WebControls.DataList dlCategory;
	
		private void Page_Load(object sender, System.EventArgs e)
		{
            if (!Page.IsPostBack)
			{
				
				// Put user code to initialize the page here
				SqlConnection objConnection = new SqlConnection(ConfigurationSettings.AppSettings["DataBaseConnection"]);
				SqlDataAdapter objAdapter = new SqlDataAdapter("SELECT * FROM Category",objConnection);
				DataSet objDataSet = new DataSet();
				objAdapter.Fill(objDataSet,"Category");
				Session["CurrentTable"]=objDataSet.Tables["Category"];
				objConnection.Close();
				dlCategory.Height = 20;
				
			}
			BindData();
		}

		#region Web Form Designer generated code
		override protected void OnInit(EventArgs e)
		{
			//
			// CODEGEN: This call is required by the ASP.NET Web Form Designer.
			//
			InitializeComponent();
			base.OnInit(e);
		}
		
		/// <summary>
		/// Required method for Designer support - do not modify
		/// the contents of this method with the code editor.
		/// </summary>
		private void InitializeComponent()
		{    
			this.dlCategory.EditCommand += new System.Web.UI.WebControls.DataListCommandEventHandler(this.dlCategory_EditCommand);
			this.btnBack.Click += new System.EventHandler(this.btnBack_Click);
			this.lbUpdate.Click += new System.EventHandler(this.lbUpdate_Click);
			this.lbCancel.Click += new System.EventHandler(this.lbCancel_Click);
			this.btnAdd.Click += new System.EventHandler(this.btnAdd_Click);
			this.Load += new System.EventHandler(this.Page_Load);

		}
		#endregion


		protected void dlCategory_EditCommand(object source, System.Web.UI.WebControls.DataListCommandEventArgs e)
		{
			this.pnlCategory.Visible=true;
			this.lbUpdate.Visible=true;
			this.lbCancel.Visible=true;
			this.lblCategory.Text = ((Literal)e.Item.Controls[1]).Text;
			this.txtCategory.Text = ((Literal)e.Item.Controls[3]).Text;
			this.txtCatDesc.Text = ((Literal)e.Item.Controls[5]).Text;
		}

	
		protected void dlCategory_DeleteCommand(object source, System.Web.UI.WebControls.DataListCommandEventArgs e)
		{
			try
			{
				//Delete from database
				SqlConnection objConnection = new SqlConnection(ConfigurationSettings.AppSettings["DataBaseConnection"]);		
				SqlCommand objCommand = new SqlCommand("DELETE Category WHERE CategoryID = "+((Literal)e.Item.Controls[1]).Text,objConnection);
				objConnection.Open();
				objCommand.ExecuteNonQuery();
				objConnection.Close();
				//Delete data in the memory table
				DataTable dtCategory = new DataTable();
				dtCategory = (DataTable)Session["CurrentTable"];
				DataView dvCategory = new DataView(dtCategory);
				dvCategory.RowFilter="CategoryID='" + ((Literal)e.Item.Controls[1]).Text + "'";
				if (dvCategory.Count > 0)
				{
					dvCategory.Delete(0);
				}
				dvCategory.RowFilter = "";
				Session["CurrentTable"]=dtCategory;
				BindData();
				this.lblMessage.Visible=false;
				this.lblMessage.Text="";
			}
			catch (Exception excep)
			{
				this.lblMessage.Text =  "Error while deleting category!!!"+excep.Message.ToString();
				this.lblMessage.Visible=true;
			}
		}

		private void lbCancel_Click(object sender, System.EventArgs e)
		{
			BindData();
			this.lblMessage.Text="";
			this.lblMessage.Visible=false;
		}

		//Common method to bind data to the datalist each time the page is refreshed
		private void BindData()
		{
			this.pnlCategory.Visible=false;
			DataTable dtCategory = new DataTable();
			//CurrentTable is the session variable that stores the category table in memory
			dtCategory = (DataTable)Session["CurrentTable"];
			//View to filter and sort data
			DataView dvCategory = new DataView(dtCategory);
			dvCategory.Sort="CategoryID";
			this.dlCategory.DataSource=dvCategory;
			this.dlCategory.DataBind();
//			if (this.btnAdd.Text=="Save")
//				this.btnAdd.Text="Add New";
		}

		private void lbUpdate_Click(object sender, System.EventArgs e)
		{
			try
			{
				//Update data in the database
				SqlConnection objConnection = new SqlConnection(ConfigurationSettings.AppSettings["DataBaseConnection"]);		
				SqlCommand objCommand = new SqlCommand("UPDATE Category SET Category = '"+this.txtCategory.Text+"', CategoryDesc = '"+this.txtCatDesc.Text+"' WHERE CategoryID = "+this.lblCategory.Text,objConnection);
				objConnection.Open();
				objCommand.ExecuteNonQuery();
				objConnection.Close();
				//Update data in the memory table
				DataTable dtCategory = new DataTable();
				dtCategory = (DataTable)Session["CurrentTable"];
				DataView dvCategory = new DataView(dtCategory);
				dvCategory.RowFilter="CategoryID=" + this.lblCategory.Text;
				if (dvCategory.Count > 0)
				{
					dvCategory.Delete(0);
				}
				dvCategory.RowFilter = "";
				DataRow drCat = dtCategory.NewRow();
				drCat[0] = this.lblCategory.Text;
				drCat[1] = this.txtCategory.Text;
				drCat[2] = this.txtCatDesc.Text;
				dtCategory.Rows.Add(drCat);
				Session["CurrentTable"]=dtCategory;
				BindData();
				this.lblCategory.Text="";
				this.txtCatDesc.Text="";
				this.txtCategory.Text="";
				this.lblMessage.Visible=false;
				this.lblMessage.Text="";
			}
			catch (Exception excep)
			{
				this.lblMessage.Text =  "更新类别时出错!!!" +excep.Message.ToString();
				this.lblMessage.Visible=true;
			}
		}

		private void btnAdd_Click(object sender, System.EventArgs e)
		{
			if (this.btnAdd.Text=="添加新类别")
			{
				this.btnAdd.Text="Save";
				this.pnlCategory.Visible=true;
				this.lbUpdate.Visible=false;
				this.lblMessage.Text =  "输入类别和说明; 单击“保存”; 插入时将会自动添加类别 ID!!!";
				this.lblMessage.Visible=true;
			}
			else
			{
				if (this.txtCategory.Text!="")
				{
					this.btnAdd.Text="添加新类别";
					try
					{
						int catid=0;

						//Save the data in the database
						SqlConnection objConnection = new SqlConnection(ConfigurationSettings.AppSettings["DataBaseConnection"]);		
					
						objConnection.Open();
							SqlCommand objCommand = new SqlCommand("Select Max(CategoryID) FROM Category",objConnection);
						if(objCommand.ExecuteScalar()!=DBNull.Value)
						{

							 catid = (int)objCommand.ExecuteScalar() + 1;
						}
						objConnection.Close();
//						string strTest="INSERT INTO Category values("+ catid + ",'" +this.txtCategory.Text+"', '"+this.txtCatDesc.Text+"')";

//						Response.Write(strTest);
						objCommand.CommandText="INSERT INTO Category values("+ catid + ",'" +this.txtCategory.Text+"', '"+this.txtCatDesc.Text+"')";
						objConnection.Open();
						objCommand.ExecuteNonQuery();
						objConnection.Close();
						//Save the data in the memory table						
						DataTable dtCategory = new DataTable();
						dtCategory = (DataTable)Session["CurrentTable"];
						DataRow drCat = dtCategory.NewRow();
						drCat[0] = catid;
						drCat[1] = this.txtCategory.Text;
						drCat[2] = this.txtCatDesc.Text;
						dtCategory.Rows.Add(drCat);
						Session["CurrentTable"]=dtCategory;
						BindData();
						this.lblCategory.Text="";
						this.txtCatDesc.Text="";
						this.txtCategory.Text="";
						this.lblMessage.Visible=false;
						this.lblMessage.Text="";
					}
					catch (Exception excep)
					{
						this.lblMessage.Text =  "添加新类别时出错!!!" +excep.Message.ToString();
						this.lblMessage.Visible=true;
					}
				}
				else
				{
					this.lblMessage.Text = "请输入数据然后单击“保存”!!!";
					this.lblMessage.Visible=true;
					this.btnAdd.Text="添加新类别";
				}
			}
		}

		private void btnBack_Click(object sender, System.EventArgs e)
		{
			Response.Redirect("Default.aspx");
		}
	}
}