C#實踐——傳統型程式顯示資料庫資料

    主要功能：
1）串連SqlServer 2000資料庫
2）顯示指定資料表中的資料
3）分條顯示查詢結果

組件設計：

  
Form1.cs
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Text;
using System.Windows.Forms;

public partial class Form1 : Form
    {
        private BindingManagerBase navigater;  //使用BindingManagerBase來移動資料記錄 
        private DataSet ds;   
        public Form1()
        {
            InitializeComponent();
           
        }

        private void button1_Click(object sender, EventArgs e)
        {
            DateHandler dbHandler = new DateHandler();
            dbHandler.connectDB();
            string commandText = "select * from users ;";
            ds = dbHandler.execSqlSelect(commandText, "users");
            navigater = this.BindingContext[ds, "users"];
            username.DataBindings.Add("Text",ds,"users.username");   //添加資料來源的綁定
            password.DataBindings.Add("Text",ds,"users.password");

        }

        private void button3_Click(object sender, EventArgs e)
        {
            if (navigater.Position == 0)
            {
                navigater.Position = navigater.Count - 1;
            }
            else
            {
                navigater.Position -= 1;
            }
          
        }

        private void button2_Click(object sender, EventArgs e)
        {
            if (navigater.Position == navigater.Count - 1)
            {
                navigater.Position = 0;
            }
            else
            {
                navigater.Position += 1;
            }
        }
    }

DateHandler.cs
using System;
using System.Collections.Generic;
using System.Text;
using System.Data;
using System.Data.SqlClient;//SqlConnection和SqlDataAdapter

class DateHandler
    {
        private SqlConnection con = null; //SQL Server資料庫連接
        public string conString = null;
        //connect to the MSSQLSERVER Instance
        public void connectDB()
        {
            conString = "Server=localhost;initial catalog=simpledb; User ID=sa; Password=10270213;Connect Timeout=4;"; 
//catalog 是 data source 的別名，指本次串連的資料庫名, Server指你的資料庫物件,本機資料用localhost
            if (con != null)
                return;
            try
            {
                con = new SqlConnection(conString);
                con.Open();
            }
            catch (Exception)
            {
                if (con != null)
                    con.Dispose();
                con = null;
                throw;
            }
        }
        public SqlDataReader execSqlSelect1(String commandTest)
        {
            SqlCommand com = new SqlCommand(commandTest, con);
            com.CommandType = CommandType.Text;
            com.CommandText = commandTest;
            SqlDataReader dateReader = com.ExecuteReader();
            return dateReader;
        }

        //查詢資料,並得到一個DataSet對象。其中newTableName是結果表的表名
        public DataSet execSqlSelect(string commandText, string newTableName)
        {
            SqlDataAdapter dAdapter;
            DataSet dSet = new DataSet();
            dAdapter = new SqlDataAdapter(commandText, con);
            dAdapter.Fill(dSet, newTableName);
            return dSet;
        }
        public int execSqlInsert(String commandTest)
        {
            SqlCommand com = new SqlCommand(commandTest, con);
            com.CommandType = CommandType.Text;
            com.CommandText = commandTest;
            int row = com.ExecuteNonQuery();
            return row;
        }
    }

資料庫表: users

運行結果：
點擊“顯示使用者資訊”

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點擊“上一條”