1、功能需求
本实例将通过c# winform实现简单的分页功能，需要的基础知识有SQL语句，c#语言基础以及c# winform的一些简单知识。
2、界面设计
这是一个简单的分页查询的界面，可以输入任意字段进行查询，这四个字段在数据准备会提到，整体界面如图1所示。
图1
中间显示是一个DataGridView，编辑好列和id，SortMode选择Automatic，意思是所有列自动铺满DataGridView，如图2所示。
图2
3、数据准备
本实例涉及到删查改，因此要有数据表以及对数据表进行操作的代码。数据库表非常简单，如图3所示，分别有对应四个字段。
图3
later_back模型类对应数据库操作类代码如下：
using MySql.Data.MySqlClient;
using System;
using System.Collections.Generic;
using System.Data;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;
using WindowsFormsApp1.Bean;
namespace WindowsFormsApp1.SqlHelper
{
class LaterBackHelper
{
public LaterBackHelper(){}
public void insert(LaterBack laterBack)
{
string sql = "insert into later_back(dormitory_id,student_no,time,reason) values('" + laterBack.Dormitory_id + "','" + laterBack.Student_no + "'," + "'" + laterBack.Time + "',"
+ "'" + laterBack.Reason + "')";
try
{
int iRet = SqlHelperBase.ExecuteSql(sql);
if (iRet > 0)
{
MessageBox.Show("新增成功", "系统提示");
}
else
{
MessageBox.Show("新增失败", "系统提示");
}
}
catch (Exception)
{
throw;
}
}
public int update(LaterBack laterBack)
{
string sql = "update later_back set reason='" + laterBack.Reason + "' where student_no= '" + laterBack.Student_no + "' and"
+ " time = '" + laterBack.Time + "' and " + " dormitory_id= '" + laterBack.Dormitory_id + "'";
try
{
int iRet = SqlHelperBase.ExecuteSql(sql);//这里返回的是受影响的行数，为int值。可以根据返回的值进行判断是否插入成功。
if (iRet > 0)
{
MessageBox.Show("修改成功", "系统提示");
}
else
{
MessageBox.Show("修改失败", "系统提示");
}
return iRet;
}
catch (Exception)
{
throw;
}
}
public int delete(LaterBack laterBack)
{
string sql = "delete from later_back where dormitory_id='" + laterBack.Dormitory_id + "' and" + " student_no= '" + laterBack.Student_no + "' and"
+ " time = '" + laterBack.Time + "' and" + " reason= '" + laterBack.Reason+"'";
try
{
int iRet = SqlHelperBase.ExecuteSql(sql);//这里返回的是受影响的行数，为int值。可以根据返回的值进行判断是否插入成功。
if (iRet > 0)
{
MessageBox.Show("删除成功", "系统提示");
}
else
{
MessageBox.Show("删除失败", "系统提示");
}
return iRet;
}
catch (Exception)
{
throw;
}
}
public List<LaterBack> getAllLaterBacks()
{
List<LaterBack> laterBacks= new List<LaterBack>();
string sql = "select * from later_back";
MySqlDataReader mySqlDataReader = SqlHelperBase.ExecuteReader(sql);
while (mySqlDataReader.Read())
{
LaterBack laterBack = new LaterBack(int.Parse(mySqlDataReader[0].ToString()), int.Parse(mySqlDataReader[1].ToString()), mySqlDataReader[2].ToString(),
mySqlDataReader[3].ToString());
laterBacks.Add(laterBack);
}
mySqlDataReader.Close();
return laterBacks;
}
public List<LaterBack> getAllLaterBacks(int student_no)
{
List<LaterBack> laterBacks= new List<LaterBack>();
string sql = "select * from later_back where student_no ='" + student_no + "'";
MySqlDataReader mySqlDataReader = SqlHelperBase.ExecuteReader(sql);
while (mySqlDataReader.Read())
{
La<b style="color:transparent">本文来源gao@!dai!ma.com搞$$代^@码!网!</b>terBack laterBack = new LaterBack(int.Parse(mySqlDataReader[0].ToString()), int.Parse(mySqlDataReader[1].ToString()), mySqlDataReader[2].ToString(),
mySqlDataReader[3].ToString());
laterBacks.Add(laterBack);
}
mySqlDataReader.Close();
return laterBacks;
}
public DataSet getAllDataSet()
{
string sql = "select * from later_back";
return SqlHelperBase.GetDataSet(sql);
}
//模糊查询
public DataSet getDataSet(LaterBack laterBack)
{
string sql="";
if(laterBack.Student_no != -1)
{
if (laterBack.Dormitory_id != -1) sql = "select * from later_back where dormitory_id like '%" + laterBack.Dormitory_id
+ "%' and student_no like '%" + laterBack.Student_no + "%' and time like '%" + laterBack.Time
+ "%' and reason like '%" + laterBack.Reason + "%'";
else sql = "select * from later_back where student_no like '%" + laterBack.Student_no + "%' and time like '%" + laterBack.Time
+ "%' and reason like '%" + laterBack.Reason + "%'";
}
else
{
if (laterBack.Dormitory_id != -1) sql = "select * from later_back where dormitory_id like '%" + laterBack.Dormitory_id
+ "%' and time like '%" + laterBack.Time+ "%' and reason like '%" + laterBack.Reason + "%'";
else sql = "select * from later_back where time like '%" + laterBack.Time
+ "%' and reason like '%" + laterBack.Reason + "%'";
}
return SqlHelperBase.GetDataSet(sql);
}
}
}
4、源码实现
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转载请注明原文链接：C# winform分页查询的实现示例
转载请注明原文链接：C# winform分页查询的实现示例
