根据数据库类型，取出数据或者是插入数据
DBAccess.cs
namespace FactoryMethod
{
public abstract class DBAccess
{
abstract public DataTable GetData();
abstract public DataTable SetData(string left, string oper, string right);
}
public class SqlServer : DBAccess// SQL Server,继承自DBAccess类
{
string connectionString = string.Empty;
SqlConnection connection = null;
SqlCommand cmd = null;
SqlDataAdapter dap = null;
DataTable table = null;
public override DataTable GetData()//读取SQL Server数据库
{
try
{
connectionString = "Data Source=.;Initial Catalog=Calculator;Integrated Security=True;Pooling=False";
connection = new SqlConnection(connectionString);
cmd = new SqlCommand("select txtLeft,txtOper,txtRight from Question", connection);
dap = new SqlDataAdapter(cmd);
table = new DataTable();
dap.Fill(table);
return table;
}
catch
{
return null;
}
finally
{
table.Dispose();
}
}
public override DataTable SetData(string left,string oper,string right) //向SQL Server数据库表中插入记录
{
connectionString = "Data Source=.;Initial Catalog=Calculator;Integrated Security=True;Pooling=False";
connection = new SqlConnection(connectionString);
string insertInfo = "insert into Question(txtLeft,txtOper,txtRight) values('" + left + "','" + oper + "','" + right + "')";
SqlCommand sqlcmd = new SqlCommand(insertInfo, connection);
connection.Open();
try
{
sqlcmd.ExecuteNonQuery();
}
catch
{
return null;
}
connection.Close();
return null;
}
}
public class Access : DBAccess//Access,继承自DBAccess类
{
string connectionString = string.Empty;
OleDbConnection connection = null;
OleDbCommand cmd = null;
OleDbDataAdapter dap = null;
DataTable table = null;
public override DataTable GetData()//读取Access数据库
{
try
{
connectionString = "Provider=Microsoft.Jet.OLEDB.4.0; Data Source=C:\\Calculator.mdb";
connection = new OleDbConnection(connectionString);
cmd = new OleDbCommand("select txtLeft,txtOper,txtRight from Question", connection);
dap = new OleDbDataAdapter(cmd);
table = new DataTable();
dap.Fill(table);
return table;
}
catch
{
return null;
}
finally
{
table.Dispose();
}
}
public override DataTable SetData(string left, string oper, string right) //向Access数据库表中插入记录
{
connectionString = "Provider=Microsoft.Jet.OLEDB.4.0; Data Source=C:\\Calculator.mdb";
connection = new OleDbConnection(connectionString);
string insertInfo = "insert into Question(txtLeft,txtOper,txtRight) values('" + left + "','" + oper + "','" + right + "')";
OleDbCommand OleDbcmd = new OleDbCommand(insertInfo, connection);
connection.Open();
try
{
OleDbcmd.ExecuteNonQuery();
}
catch
{
return null;
}
connection.Close();
return null;
}
}
}
抽象工厂类
CreateDBFactory.cs
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
namespace FactoryMethod
{
public abstract class CreateDBFactory// 抽象工厂类
{
abstract public DBAccess createDataBase(); // 工厂方法
}
public class SqlServerFactory : CreateDBFactory// SQL Server工厂，继承自CreateDBFactory类
{
// 返回SQL Server数据库
public override DBAccess createDataBase()
{
return new SqlServer();
}
}
public class AccessFactory : CreateDBFactory//Access工厂，继承自CreateDBFactory类
{
public override DBAccess createDataBase()// 返回Access数据库
{
return new Access();
}
}
}
FrmQuestion.cs
namespace FactoryMethod
{
public partial class FrmQuestion : Form
{
public FrmQuestion()
{
InitializeComponent();
this.RSql.CheckedChanged += new EventHandler(rbtn_CheckedChanged);
this.RAccess.CheckedChanged += new EventHandler(rbtn_CheckedChanged);
this.RTxt.CheckedChanged += new EventHandler(rbtn_CheckedChanged);
}
private string selectedDB = null;
void rbtn_CheckedChanged(object sender, EventArgs e)
{
selectedDB = ((RadioButton)sender).Text;
this.lblSelectedInfo.Text = "您选择了" + selectedDB + "数据源！";
this.gboxSelect.Enabled = false;
this.btnShowData.Enabled = true;
}
private void btnSelectNewDB_Click(object sender, EventArgs e)//切换数据库
{
if (this.gboxSelect.Enabled == true)
{
MessageBox.Show("您还没有选择数据源，请选择！", "提示！", MessageBoxButtons.OK, MessageBoxIcon.Asterisk);
}
this.RSql.Checked = false;
this.RAccess.Checked = false;
this.RTxt.Checked = false;
this.gboxSelect.Enabled = true;
this.lblSelectedInfo.Text = null;
this.btnShowData.Enabled = false;
this.dgvData.DataSource = null;
}
private void btnShowData_Click(object sender, EventArgs e)//在DataGridView中显示数据
{
switch (selectedDB)
{
case "SQL Server":
this.dgvData.DataSource = new SqlServerFactory().createDataBase().GetData();
string selInfo = "select ID,txtLeft,txtOper,txtRight from Question";
string connectionString = "Data Source=.;Initial Catalog=Calculator;Integrated Security=True;Pooling=False";
SqlConnection conn = new SqlConnection(connectionString);
SqlDataAdapter adapter;
DataSet ds = new DataSet();
DataTable dt;
conn.Open();
adapter = new SqlDataAdapter(selInfo, conn);
adapter.Fill(ds, "Question");
dt = ds.Tables["Question"];
comboxID.ValueMember = "ID";
comboxID.DataSource = dt;
conn.Close();
break;
case "Txt":
string[] n1 = new string[100];
n1 = File.ReadAllLines("Left.txt");
txtLeft.Text = n1[0];
string[] n2 = new string[100];
n2 = File.ReadAllLines("Oper.txt");
txtOper.Text = n2[0];
string[] n3 = new string[100];
n3 = File.ReadAllLines("Right.txt");
txtRight.Text = n3[0];
break;
case "Access":
this.dgvData.DataSource = new AccessFactory().createDataBase().GetData();
string selInfo1 = "select ID,txtLeft,txtOper,txtRight from Question";
string connectionString1 = "Provider=Microsoft.Jet.OLEDB.4.0; Data Source=C:\\Calculator.mdb";
OleDbConnection conn1 = new OleDbConnection(connectionString1);
OleDbDataAdapter adapter1;
DataSet ds1 = new DataSet();
DataTable dt1;
conn1.Open();
adapter1 = new OleDbDataAdapter(selInfo1, conn1);
adapter1.Fill(ds1, "Question");
dt1 = ds1.Tables["Question"];
comboxID.ValueMember = "ID";
comboxID.DataSource = dt1;
conn1.Close();
break;
default:
break;
}
}
private void btnAdd_Click(object sender, EventArgs e) //在DataGridView中插入数据
{
string symbol = txtOper.Text;
string a = txtLeft.Text;
string b = txtRight.Text;
switch (selectedDB)
{
case "SQL Server":
this.dgvData.DataSource = new SqlServerFactory().createDataBase().SetData(a, symbol, b);
MessageBox.Show("数据插入成功！");
txtLeft.Clear();
txtOper.Clear();
txtRight.Clear();
break;
case "Txt":
StreamWriter Left = File.AppendText("Left.txt");
Left.WriteLine(txtLeft.Text);
Left.Close();
StreamWriter Oper = File.AppendText("Oper.txt");
Oper.WriteLine(txtOper.Text);
Oper.Close();
StreamWriter Right = File.AppendText("Right.txt");
Right.WriteLine(txtRight.Text);
Right.Close();
MessageBox.Show("数据插入成功！");
txtLeft.Clear();
txtOper.Clear();
txtRight.Clear();
break;
case "Access":
this.dgvData.DataSource = new AccessFactory().createDataBase().SetData(a, symbol, b);
MessageBox.Show("数据插入成功！");
txtLeft.Clear();
txtOper.Clear();
txtRight.Clear();
break;
default:
break;
}
}
private void btnNext_Click(object sender, EventArgs e)
{
int n = 1;
string[] n1 = new string[100];
n1 = File.ReadAllLines("Left.txt");
txtLeft.Text = n1[n];
string[] n2 = new string[100];
n2 = File.ReadAllLines("Oper.txt");
txtOper.Text = n2[n];
string[] n3 = new string[100];
n3 = File.ReadAllLines("Right.txt");
txtRight.Text = n3[n];
n++;
}
private void comboxID_SelectedIndexChanged(object sender, EventArgs e)
{
switch (selectedDB)
{
case "SQL Server":
string selInfo = "select txtLeft,txtOper,txtRight from Question where ID='" + comboxID.Text.ToString().Trim() + "'";
string connectionString = "Data Source=.;Initial Catalog=Calculator;Integrated Security=True;Pooling=False";
SqlConnection conn = new SqlConnection(connectionString);
SqlCommand sqlcmd = new SqlCommand(selInfo, conn);
SqlDataReader sdr;
conn.Open();
sdr = sqlcmd.ExecuteReader();
if (sdr.Read())
{
txtLeft.Text = sdr["txtLeft"].ToString();
txtOper.Text = sdr["txtOper"].ToString();
txtRight.Text = sdr["txtRight"].ToString();
}
conn.Close();
break;
case "Access":
string selInfo1 = "select txtLeft,txtOper,txtRight from Question where ID='" + comboxID.Text.ToString().Trim() + "'";
string connectionString1 = "Provider=Microsoft.Jet.OLEDB.4.0; Data Source=C:\\Calculator.mdb";
OleDbConnection conn1 = new OleDbConnection(connectionString1);
OleDbCommand sqlcmd1 = new OleDbCommand(selInfo1, conn1);
OleDbDataReader sdr1;
conn1.Open();
sdr1 = sqlcmd1.ExecuteReader();
if (sdr1.Read())
{
txtLeft.Text = sdr1["txtLeft"].ToString();
txtOper.Text = sdr1["txtOper"].ToString();
txtRight.Text = sdr1["txtRight"].ToString();
}
conn1.Close();
break;
default:
break;
}
}
private void textBox4_KeyDown(object sender, KeyEventArgs e)
{
string symbol = txtOper.Text;
double a = Convert.ToDouble(txtLeft.Text);
double b = Convert.ToDouble(txtRight.Text);
Context contex = null;
if (symbol == "+")
{
contex = new Context(new Add()); //加法策略
}
else if (symbol == "-")
{
contex = new Context(new Sub()); //减法策略
}
else if (symbol == "*") //若为乘号
{
contex = new Context(new Mul()); //乘法策略
}
else if (symbol == "/") //若为乘号
{
contex = new Context(new Div()); //除法策略
}
string answer = contex.Cal(a, b, symbol).ToString(); //用answer来存计算出来的答案,此时已经计算出a,b两个数的运算结果。
if (e.KeyCode == Keys.Enter) //回车操作
{
string result = txtLeft.Text + txtOper.Text + txtRight.Text;//把运算式子存在result里面
if (textBox4.Text == answer) //如果输入答案与计算出的answer相等
{
MessageBox.Show("回答正确！"); //弹出回答正确
listBox1.Items.Add(result + "=" + textBox4.Text.Trim() + "√");//并把运算式子存在listbox里
}
else //如果答错
{
MessageBox.Show("答题错误！"); //弹出答题错误
listBox1.Items.Add(result + "=" + textBox4.Text.Trim() + "×");//同样把运算式子放在listbox
}
textBox4.Clear();
}
}
}
}
1.新建一个数据库
2.单选按钮选中数据库，从而确定数据库的类型，并且往Txt数据源插入数据
3.此时程序自动新建了三个txt文本文件来作为数据源
4.txt数据源答题时
5.使用txt数据源做了2题后切换数据源，此时同样可以使用SQL Server数据源来答题。
