frmcategory.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。

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

namespace SupermarketProject
{
	/// <summary>
	/// Summary description for frmCategory.
	/// </summary>
	public class frmCategory : System.Windows.Forms.Form
	{
		private System.Windows.Forms.TreeView tvwCatCode;
		private System.Windows.Forms.Label lblDesc;
		private System.Windows.Forms.Label lblCatCode;
		private System.Windows.Forms.Label lblRate;
		private System.Windows.Forms.TextBox txtCatCode;
		private System.ComponentModel.IContainer components;

		private System.Windows.Forms.NumericUpDown updRate;
		private System.Windows.Forms.TextBox txtCatDesc;
		private System.Windows.Forms.Button btnInsert;
		private System.Windows.Forms.Button btnUpdate;
		private System.Windows.Forms.Button btnExit;
		private System.Windows.Forms.Label label1;
		private System.Windows.Forms.TextBox txtCatTitle;
		private System.Windows.Forms.TextBox txtFlvlCatCode;
		private System.Windows.Forms.Label lblFlvlCatCode;
		private System.Windows.Forms.HelpProvider hlpCategory;
		private System.Windows.Forms.ToolTip tipCategory;

		//other variables
		private decimal rate;
		private string catCode;
		private System.Windows.Forms.ErrorProvider errCategory;
		private bool flag = false;
		private bool allValidated = false;
        public static bool addflag = false;
        private bool treePopulated = false;		
        private string errorMsg;
		private Settings settings;

		public frmCategory()
		{
			InitializeComponent();
			settings = new Settings();
            this.hlpCategory.HelpNamespace = settings.uiDirectory+ @"\HELP\SupermarketHelp.chm"; 
		}

		/// <summary>
		/// Clean up any resources being used.
		/// </summary>
		protected override void Dispose( bool disposing )
		{
			if( disposing )
			{
				if(components != null)
				{
					components.Dispose();
				}
			}
			base.Dispose( disposing );
		}

		#region Windows Form Designer generated code
		/// <summary>
		/// Required method for Designer support - do not modify
		/// the contents of this method with the code editor.
		/// </summary>
		private void InitializeComponent()
		{
			this.components = new System.ComponentModel.Container();
			this.tvwCatCode = new System.Windows.Forms.TreeView();
			this.lblDesc = new System.Windows.Forms.Label();
			this.lblCatCode = new System.Windows.Forms.Label();
			this.lblRate = new System.Windows.Forms.Label();
			this.txtCatDesc = new System.Windows.Forms.TextBox();
			this.txtCatCode = new System.Windows.Forms.TextBox();
			this.updRate = new System.Windows.Forms.NumericUpDown();
			this.btnInsert = new System.Windows.Forms.Button();
			this.btnUpdate = new System.Windows.Forms.Button();
			this.btnExit = new System.Windows.Forms.Button();
			this.errCategory = new System.Windows.Forms.ErrorProvider();
			this.label1 = new System.Windows.Forms.Label();
			this.txtCatTitle = new System.Windows.Forms.TextBox();
			this.txtFlvlCatCode = new System.Windows.Forms.TextBox();
			this.lblFlvlCatCode = new System.Windows.Forms.Label();
			this.hlpCategory = new System.Windows.Forms.HelpProvider();
			this.tipCategory = new System.Windows.Forms.ToolTip(this.components);
			((System.ComponentModel.ISupportInitialize)(this.updRate)).BeginInit();
			this.SuspendLayout();
			// 
			// tvwCatCode
			// 
			this.tvwCatCode.ImageIndex = -1;
			this.tvwCatCode.Location = new System.Drawing.Point(0, 0);
			this.tvwCatCode.Name = "tvwCatCode";
			this.tvwCatCode.SelectedImageIndex = -1;
			this.hlpCategory.SetShowHelp(this.tvwCatCode, true);
			this.tvwCatCode.Size = new System.Drawing.Size(797, 258);
			this.tvwCatCode.TabIndex = 0;
			this.tvwCatCode.Click += new System.EventHandler(this.tvwCatCode_Click);
			this.tvwCatCode.MouseHover += new System.EventHandler(this.tvwCatCode_MouseHover);
			this.tvwCatCode.AfterSelect += new System.Windows.Forms.TreeViewEventHandler(this.tvwCatCode_AfterSelect);
			// 
			// lblDesc
			// 
			this.lblDesc.Location = new System.Drawing.Point(0, 284);
			this.lblDesc.Name = "lblDesc";
			this.lblDesc.Size = new System.Drawing.Size(120, 25);
			this.lblDesc.TabIndex = 9;
			this.lblDesc.Text = "说明";
			this.lblDesc.TextAlign = System.Drawing.ContentAlignment.MiddleLeft;
			// 
			// lblCatCode
			// 
			this.lblCatCode.Location = new System.Drawing.Point(355, 284);
			this.lblCatCode.Name = "lblCatCode";
			this.lblCatCode.Size = new System.Drawing.Size(96, 25);
			this.lblCatCode.TabIndex = 1;
			this.lblCatCode.Text = "产品代码";
			this.lblCatCode.TextAlign = System.Drawing.ContentAlignment.MiddleLeft;
			// 
			// lblRate
			// 
			this.lblRate.Location = new System.Drawing.Point(634, 276);
			this.lblRate.Name = "lblRate";
			this.lblRate.Size = new System.Drawing.Size(38, 24);
			this.lblRate.TabIndex = 7;
			this.lblRate.Text = "费率";
			this.lblRate.TextAlign = System.Drawing.ContentAlignment.MiddleLeft;
			// 
			// txtCatDesc
			// 
			this.txtCatDesc.Location = new System.Drawing.Point(86, 276);
			this.txtCatDesc.Multiline = true;
			this.txtCatDesc.Name = "txtCatDesc";
			this.txtCatDesc.Size = new System.Drawing.Size(240, 103);
			this.txtCatDesc.TabIndex = 10;
			this.txtCatDesc.Text = "";
			this.txtCatDesc.Validating += new System.ComponentModel.CancelEventHandler(this.txtCatDesc_Validating);
			this.txtCatDesc.Validated += new System.EventHandler(this.txtCatDesc_Validated);
			this.txtCatDesc.MouseHover += new System.EventHandler(this.txtCatDesc_MouseHover);
			// 
			// txtCatCode
			// 
			this.txtCatCode.Location = new System.Drawing.Point(499, 276);
			this.txtCatCode.Name = "txtCatCode";
			this.txtCatCode.ReadOnly = true;
			this.txtCatCode.Size = new System.Drawing.Size(120, 21);
			this.txtCatCode.TabIndex = 2;
			this.txtCatCode.Text = "";
			this.txtCatCode.MouseHover += new System.EventHandler(this.txtCatCode_MouseHover);
			// 
			// updRate
			// 
			this.updRate.Location = new System.Drawing.Point(701, 276);
			this.updRate.Name = "updRate";
			this.updRate.Size = new System.Drawing.Size(86, 21);
			this.updRate.TabIndex = 8;
			this.updRate.Validating += new System.ComponentModel.CancelEventHandler(this.updRate_Validating);
			this.updRate.Validated += new System.EventHandler(this.updRate_Validated);
			this.updRate.ValueChanged += new System.EventHandler(this.updRate_ValueChanged);
			// 
			// btnInsert
			// 
			this.btnInsert.Enabled = false;
			this.btnInsert.Location = new System.Drawing.Point(29, 405);
			this.btnInsert.Name = "btnInsert";
			this.btnInsert.Size = new System.Drawing.Size(90, 43);
			this.btnInsert.TabIndex = 11;
			this.btnInsert.Text = "插入(&I)";
			this.btnInsert.Click += new System.EventHandler(this.btnInsert_Click);
			this.btnInsert.MouseHover += new System.EventHandler(this.btnInsert_MouseHover);
			// 
			// btnUpdate
			// 
			this.btnUpdate.Enabled = false;
			this.btnUpdate.Location = new System.Drawing.Point(134, 405);
			this.btnUpdate.Name = "btnUpdate";
			this.btnUpdate.Size = new System.Drawing.Size(90, 43);
			this.btnUpdate.TabIndex = 12;
			this.btnUpdate.Text = "更新(&U)";
			this.btnUpdate.Click += new System.EventHandler(this.btnUpdate_Click);
			this.btnUpdate.MouseHover += new System.EventHandler(this.btnUpdate_MouseHover);
			// 
			// btnExit
			// 
			this.btnExit.Location = new System.Drawing.Point(240, 405);
			this.btnExit.Name = "btnExit";
			this.btnExit.Size = new System.Drawing.Size(90, 43);
			this.btnExit.TabIndex = 13;
			this.btnExit.Text = "退出(&E)";
			this.btnExit.Click += new System.EventHandler(this.btnExit_Click);
			// 
			// errCategory
			// 
			this.errCategory.ContainerControl = this;
			// 
			// label1
			// 
			this.label1.Location = new System.Drawing.Point(355, 370);
			this.label1.Name = "label1";
			this.label1.Size = new System.Drawing.Size(96, 25);
			this.label1.TabIndex = 5;
			this.label1.Text = "类别名称";
			this.label1.TextAlign = System.Drawing.ContentAlignment.MiddleLeft;
			// 
			// txtCatTitle
			// 
			this.txtCatTitle.Location = new System.Drawing.Point(499, 370);
			this.txtCatTitle.Name = "txtCatTitle";
			this.txtCatTitle.Size = new System.Drawing.Size(202, 21);
			this.txtCatTitle.TabIndex = 6;
			this.txtCatTitle.Text = "";
			this.txtCatTitle.Validating += new System.ComponentModel.CancelEventHandler(this.txtCatTitle_Validating);
			this.txtCatTitle.Validated += new System.EventHandler(this.txtCatTitle_Validated);
			this.txtCatTitle.MouseHover += new System.EventHandler(this.txtCatTitle_MouseHover);
			// 
			// txtFlvlCatCode
			// 
			this.txtFlvlCatCode.Location = new System.Drawing.Point(499, 319);
			this.txtFlvlCatCode.Name = "txtFlvlCatCode";
			this.txtFlvlCatCode.Size = new System.Drawing.Size(120, 21);
			this.txtFlvlCatCode.TabIndex = 4;
			this.txtFlvlCatCode.Text = "";
			this.txtFlvlCatCode.Validating += new System.ComponentModel.CancelEventHandler(this.txtFlvlCatCode_Validating);
			this.txtFlvlCatCode.Validated += new System.EventHandler(this.txtFlvlCatCode_Validated);
			this.txtFlvlCatCode.MouseHover += new System.EventHandler(this.txtFlvlCatCode_MouseHover);
			// 
			// lblFlvlCatCode
			// 
			this.lblFlvlCatCode.Location = new System.Drawing.Point(355, 319);
			this.lblFlvlCatCode.Name = "lblFlvlCatCode";
			this.lblFlvlCatCode.Size = new System.Drawing.Size(106, 34);
			this.lblFlvlCatCode.TabIndex = 3;
			this.lblFlvlCatCode.Text = "第一层类别代码";
			this.lblFlvlCatCode.TextAlign = System.Drawing.ContentAlignment.MiddleLeft;
			// 
			// tipCategory
			// 
			this.tipCategory.AutomaticDelay = 150;
			// 
			// frmCategory
			// 
			this.AutoScaleBaseSize = new System.Drawing.Size(6, 14);
			this.ClientSize = new System.Drawing.Size(825, 462);
			this.Controls.Add(this.lblFlvlCatCode);
			this.Controls.Add(this.txtFlvlCatCode);
			this.Controls.Add(this.txtCatTitle);
			this.Controls.Add(this.txtCatCode);
			this.Controls.Add(this.txtCatDesc);
			this.Controls.Add(this.label1);
			this.Controls.Add(this.btnExit);
			this.Controls.Add(this.btnUpdate);
			this.Controls.Add(this.btnInsert);
			this.Controls.Add(this.updRate);
			this.Controls.Add(this.lblRate);
			this.Controls.Add(this.lblCatCode);
			this.Controls.Add(this.lblDesc);
			this.Controls.Add(this.tvwCatCode);
			this.Name = "frmCategory";
			this.Text = "产品类别";
			this.Closing += new System.ComponentModel.CancelEventHandler(this.frmCategory_Closing);
			this.Paint += new System.Windows.Forms.PaintEventHandler(this.frmCategory_Paint);
			((System.ComponentModel.ISupportInitialize)(this.updRate)).EndInit();
			this.ResumeLayout(false);

		}
		#endregion

		public void populateTree()
		{
			try
			{
				this.flag  =  false; // for the next add operation
				//if tree exists, delete it and create fresh new tree with latest records
				if (this.tvwCatCode.GetNodeCount(true) > 0)
				{
					this.tvwCatCode.SelectedNode = this.tvwCatCode.TopNode; 
					this.tvwCatCode.Nodes.Remove(this.tvwCatCode.SelectedNode); 
		
				}
				//retrieve data for the treeview from the table
				DataConnection.commnd.CommandText  = "Select catcode,flvlcatcode from productcategories order by flvlcatcode";
				OleDbDataReader reader  =  DataConnection.commnd.ExecuteReader();
				if (reader.HasRows)
				{
				//create root node for the tree view
				TreeNode node  =  this.tvwCatCode.Nodes.Add("产品类别");
				TreeNode newNode  =  new TreeNode ();
				
				string current,parent;

				while(reader.Read ())
					{
						current = reader.GetString(0);
						parent = reader.GetString(1);
						//if this node has no parent category, add this node to the root node
						if(parent.Equals ("00"))
						{
							newNode = new TreeNode (current);