queryfrm.cs

简单数据库

using System;
using System.Collections;
using System.Collections.Generic;
using System.ComponentModel;
using System.Diagnostics;
using System.Data;
using System.Threading;
using System.Drawing;
using QueryToolHelper;
using System.Text;
using System.Windows.Forms;

namespace QueryTool_V1
{
    enum State
    {
        Ready,
        Working,
        Completed        
    }   

    public partial class QueryFrm : Form
    {
        // Member Variables
        public TimeSpan laspedTime;
        public bool cellIsUpdated;
        public bool calenderFlag;
        public DataGVCellCollection cell_list;
        public TabPage currentSelectedTabPage;
        ArrayList _columnList;
        ArrayList _columnListSelected;
        ArrayList _columnListNotSelected;
        public DataTable resultTable;
        CDataColumns objDataColumns;
        public COperator _operators;

        // Result Window
        Label lblEmployeeID;
        TextBox txtEmployeeID;
        Label lblEmployeeName;
        TextBox txtEmployeeName;

        class ShowProgressArgs : EventArgs 
        {
            public string _statusText;
            public State _state;                      

            public ShowProgressArgs(string statusText, State state) 
            {
                this._statusText = statusText;
                this._state = state;                
            }
        }
        class TimeArgs : EventArgs
        {
            public string _hours;
            public string _minutes;
            public string _seconds;
            public State _state;

            public TimeArgs(string hours, string minutes, string seconds, State state)
            {
                this._hours = hours;
                this._minutes = minutes;
                this._seconds = seconds;
                this._state = state;
            }
        }
        public delegate void ShowProgressHandler(object sender, ShowProgressArgs e);
        public delegate void UpdateTimeHandler(object sender, TimeArgs e);
        
        public QueryFrm()
        {
            InitializeComponent();
            runQueryToolStripMenuItem.Visible = false;
            saveToolStripMenuItem.Visible = false;
            deleteClauseToolStripMenuItem.Visible = false;
            cellIsUpdated = true;
            calenderFlag = false;
            _columnList = new ArrayList();
            _columnListSelected = new ArrayList();
            _columnListNotSelected = new ArrayList();
            _operators = new COperator();
            
        }

        private void tabControl1_SelectedIndexChanged(object sender, EventArgs e)
        {
            if (tabControl1.SelectedTab.Text.Contains("Query"))
            {
                // Query Window
                runQueryToolStripMenuItem.Visible = false;
                saveToolStripMenuItem.Visible = false;
                openQueryToolStripMenuItem.Visible = true;
            }
            else
            {
                // Result Window
                runQueryToolStripMenuItem.Visible = true;
                saveToolStripMenuItem.Visible = true;
                openQueryToolStripMenuItem.Visible = false;
            }
        }

        void ShowProgress(object sender, ShowProgressArgs e)
        {
            // Make sure we're on the right thread
            if (this.InvokeRequired == false)
            {
                if (e._state == State.Working)
                {
                    // Make the Progress Bar Visible
                    progressBarStatus.Visible = true;
                    lblStatus.Text = e._statusText;
                    progressBarStatus.Style = ProgressBarStyle.Marquee;
                    StartTimer();
                }
                if (e._state == State.Completed)
                {
                    progressBarStatus.Style = ProgressBarStyle.Blocks;
                    progressBarStatus.Value = 0;
                    progressBarStatus.Visible = false;
                    lblStatus.Text = e._statusText;
                    EndTimer();
                }
            }
            // Transfer control to correct thread
            else
            {
                ShowProgressHandler
                  showProgress =
                  new ShowProgressHandler(ShowProgress);
                Invoke(showProgress, new object[] { sender, e });
            }
        }

        public delegate void InitializeDatabaseDelegate();
        public delegate void InitializeDataGridViewDelegate();
        private void InitializeDatabase()
        {
            object sender = System.Threading.Thread.CurrentThread;
            ShowProgressArgs e = new ShowProgressArgs("Retrieving...", State.Working);            
            ShowProgress(sender, e);
            Thread.Sleep(new TimeSpan(0,0,1));
            // Connect to Database and populate the Data Columns
            objDataColumns = new CDataColumns();
            
            e = new ShowProgressArgs("Ready", State.Completed);
            ShowProgress(sender, e);            
        }
        private void InitializeDatabaseCompleted(IAsyncResult result)
        {
            // In ASyncCallBack, we are not in the same thread as the that of the Form UI Thread
            InitializeDatabaseDelegate initializeDB = (InitializeDatabaseDelegate)result.AsyncState;
            initializeDB.EndInvoke(result);
            InitializeDataGridView();
        }
        private void InitializeDataGridView()
        {

            if (!this.InvokeRequired)// Make sure we're on the right thread
            {
                // Populate the DataGridView            
                runQueryToolStripMenuItem.Visible = true;
                // Change to edit mode when user enters a cell.
                dataGridViewQuery.EditMode = DataGridViewEditMode.EditOnEnter;

                // ------------------------------------------------            
                // First create the columns
                dataGridViewQuery.Columns.Add("AndOr", "And/Or");
                dataGridViewQuery.Columns.Add("Field", "Field");
                dataGridViewQuery.Columns.Add("Operator", "Operator");
                dataGridViewQuery.Columns.Add("Value", "Value");


                // ------------------------------------------------
                // Create a row and add a textbox cell
                DataGridViewRow dataGridRow = new DataGridViewRow();
                DataGridViewCell[] cells = new DataGridViewCell[4];
                DataGridViewTextBoxCell txt00 = new DataGridViewTextBoxCell();
                DataGridViewTextBoxCell txt01 = new DataGridViewTextBoxCell();
                DataGridViewTextBoxCell txt02 = new DataGridViewTextBoxCell();
                DataGridViewTextBoxCell txt03 = new DataGridViewTextBoxCell();

                txt00.Value = string.Empty;
                txt01.Value = "DataTable";
                txt02.Value = "Equals";
                txt03.Value = "EmployeeInfo";

                dataGridRow.Cells.Add(txt00);
                txt00.ReadOnly = true;
                dataGridRow.Cells.Add(txt01);
                txt01.ReadOnly = true;
                dataGridRow.Cells.Add(txt02);
                txt02.ReadOnly = true;
                dataGridRow.Cells.Add(txt03);
                txt03.ReadOnly = true;
                dataGridViewQuery.Rows.Add(dataGridRow);
                dataGridViewQuery[3, 0].DataGridView.Width = 20;
                dataGridViewQuery.ReadOnly = true;

                this.dataGridViewQuery.CellClick += new DataGridViewCellEventHandler(dataGridViewQuery_CellClick);
                this.dataGridViewQuery.CellValueChanged += new DataGridViewCellEventHandler(dataGridViewQuery_CellValueChanged);
                
            }
            else // Transfer control to correct thread ***
            {
                InitializeDataGridViewDelegate initializeGV = new InitializeDataGridViewDelegate(InitializeDataGridView);
                Invoke(initializeGV, new object[] { });                
            }
        }
        private void openQueryToolStripMenuItem_Click(object sender, EventArgs e)
        {
            // Clear the DataGridView First
            dataGridViewQuery.Rows.Clear();
            dataGridViewQuery.Columns.Clear();
            deleteClauseToolStripMenuItem.Visible = true;
            // Create Object of DataGridViewCell Collection
            cell_list = new DataGVCellCollection();

            // Initialize Database
            // Asynch delegate method
            InitializeDatabaseDelegate initializeDB = new InitializeDatabaseDelegate(InitializeDatabase);
            initializeDB.BeginInvoke(new AsyncCallback(InitializeDatabaseCompleted), initializeDB);
            
        }

        // This Code Module has bugs
        // 1. Not to allow user to select any node, it should be in sequence
        // 2. Did not validate values entered by the user
        private void dataGridViewQuery_CellClick(object sender, DataGridViewCellEventArgs e)
        {
            
            // Data
            DataGVCell dataCell = null;

            // check if the previous any cell is not updated
            bool previousAnyCellnotUpdated = false;
            
            // check if cell is already added to list
            bool cellAdded = false;
            
            if (cell_list != null)
            {              
                foreach (DataGVCell dataGVCell in cell_list)
                {
                    if (dataGVCell._rowIndex == e.RowIndex && dataGVCell._columnIndex == e.ColumnIndex)
                    {
                        cellAdded = true;                                           
                        break;                   
                    }
                }
                if (!cellAdded)
                {
                    dataCell = new DataGVCell(e.RowIndex, e.ColumnIndex, false, string.Empty, false);
                    cell_list.Add(dataCell);
                    cellAdded = true;
                }
            }
            
            

            foreach (DataGVCell dataGVCell in cell_list)
            {
                if (dataGVCell._cellValue.Equals(""))
                {
                    if (dataGVCell._rowIndex != e.RowIndex || dataGVCell._columnIndex != e.ColumnIndex) //Current Cell
                    {
                        previousAnyCellnotUpdated = true;
                        break;
                    }
                }
            }
            
            if (!previousAnyCellnotUpdated) // To make sure the previous cell is updated
            {