实例介绍
【实例简介】邮件信息系统
【实例截图】
【核心代码】
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;
using Excel = Microsoft.Office.Interop.Excel;
using System.Data.SqlClient;
namespace EmailUserDB
{
public partial class Form1 : Form
{
public Form1()
{
InitializeComponent();
}
SqlConnection con;
private void DBCon()
{
string constr = "Data Source=LAPTOP-LKC9B40K;Initial Catalog=EmailUserDB;Integrated Security=True";
con = new SqlConnection(constr);
}
private void DView()
{
try
{
DBCon();
string sql = string.Format("select * from EmailUsers");
DataSet ds = new DataSet();
SqlDataAdapter dar = new SqlDataAdapter(sql, con);
dar.Fill(ds);
dataGridView1.DataSource = ds.Tables[0];
comboBox1.DisplayMember = "username";//绑定前端需要显示的字段，语句
comboBox1.DataSource = ds.Tables[0].DefaultView;//绑定数据源
comboBox1.ValueMember = "username";//绑定数据的标识，一般是ID
}
catch (SystemException ex)
{
MessageBox.Show("错误" ex.Message, "错误提示", MessageBoxButtons.OKCancel, MessageBoxIcon.Information);
}
finally
{
if (con.State == ConnectionState.Open)//判断通道状态
{
con.Close();
con.Dispose();
}
}
}
private bool dbUpdate()
{
string sql = "select * from EmailUsers";
DataTable dt1 = new DataTable();
SqlDataAdapter dar = new SqlDataAdapter(sql, con);
dar.Fill(dt1);
dt1.Rows.Clear();
DataTable dt2 = new DataTable();
dt2 = (DataTable)dataGridView1.DataSource;
for (int i = 0; i < dt2.Rows.Count; i )
{
dt1.ImportRow(dt2.Rows[i]);
}
try
{
this.con.Open();
SqlCommandBuilder cb = new SqlCommandBuilder(dar);//批量更新数据库
dar.Update(dt1);
con.Close();
}
catch(Exception ex)
{
MessageBox.Show("保存出错！！" ex.Message);
return false;
}
dt1.AcceptChanges();
return true;
}
private void Form1_Load(object sender, EventArgs e)
{
// TODO: 这行代码将数据加载到表“emailUserDBDataSet.EmailUsers”中。您可以根据需要移动或删除它。
this.emailUsersTableAdapter.Fill(this.emailUserDBDataSet.EmailUsers);
DView();
}
private void bnt_insert_Click(object sender, EventArgs e)
{
DBCon();
string username = comboBox1.Text.Trim();
string pwd = textBox1.Text.Trim();
string name = textBox2.Text.Trim();
string sql = string.Format("insert into EmailUsers values('{0}','{1}','{2}')",username,pwd,name);
SqlCommand cmd = new SqlCommand(sql,con);
con.Open();
cmd.ExecuteNonQuery();
con.Close();
DView();
}
private void bnt_update_Click(object sender, EventArgs e)
{
DBCon();
string username = comboBox1.Text;
string pwd = textBox1.Text.Trim();
string name = textBox2.Text.Trim();
string sql = string.Format("update EmailUsers set password='{0}' , realname='{1}' where username='{2}'",pwd,name,username);
SqlCommand cmd = new SqlCommand(sql, con);
con.Open();
cmd.ExecuteNonQuery();
con.Close();
DView();
}
private void bnt_delect_Click(object sender, EventArgs e)
{
DBCon();
string username = comboBox1.Text.Trim();
string sql = string.Format("delete EmailUsers where username='{0}'",username);
SqlCommand cmd = new SqlCommand(sql,con);
con.Open();
cmd.ExecuteNonQuery();
con.Close();
DView();
comboBox1.Text = "";
textBox1.Text = "";
textBox2.Text = "";
}
private void bnt_select_Click(object sender, EventArgs e)
{
DBCon();
string username = comboBox1.Text;
string pwd = textBox1.Text.Trim();
string name = textBox1.Text.Trim();
string sql = string.Format("select * from EmailUsers where username='{0}' password='{1}' realname='{2}'", username,pwd, name);
SqlCommand cmd = new SqlCommand(sql, con);
con.Open();
DataTable dt = new DataTable();
SqlDataAdapter dar = new SqlDataAdapter(sql, con);
dar.Fill(dt);
dataGridView1.DataSource = dt;
con.Close();
}
private void button1_Click(object sender, EventArgs e)
{
string Sql = "select * from EmailUsers";
SqlDataAdapter sda = new SqlDataAdapter(Sql, con);
DataSet ds = new DataSet();
sda.Fill(ds);
DataView dv = ds.Tables[0].DefaultView;
if (radioButton1.Checked)
{
dv.Sort = "username";
}
else if (radioButton2.Checked)
{
dv.Sort = "password";
}
else
{
dv.Sort = "realname";
}
dataGridView1.DataSource = dv;
button3.Text = "编辑数据";
}
private void button2_Click(object sender, EventArgs e)
{
string strSql = "select * from EmailUsers";
SqlDataAdapter sda = new SqlDataAdapter(strSql, con);
DataSet ds = new DataSet();
DataView dv = ds.Tables[0].DefaultView;
if (radioButton1.Checked)
{
dv.RowFilter = string.Format("username like '{0}'",comboBox1.Text);
}
else if (radioButton2.Checked)
{
dv.RowFilter =string.Format("password like '{0}'",textBox1.Text.Trim());
}
else
{
dv.RowFilter = string.Format("realname like '{0}'",textBox2.Text.Trim());
}
dv.RowStateFilter = DataViewRowState.CurrentRows;
dataGridView1.DataSource = dv;
button3.Text = "编辑数据";
}
private void button3_Click(object sender, EventArgs e)
{
if (button3.Text == "保存数据编辑")
{
if (dbUpdate())
{
MessageBox.Show("数据库操作成功！", "提示", MessageBoxButtons.OK, MessageBoxIcon.Information);
}
button3.Text = "编辑数据";
}
else
{
DView();
button3.Text = "保存数据编辑";
}
}
private bool DataGridviewToExcel(DataGridView dg, bool ShowExcle)
{
if (dg.Rows.Count == 0) return false;
Excel.Application ex = new Excel.Application();
ex.Application.Workbooks.Add(true);
ex.Visible = ShowExcle;
for (int i = 0; i < dg.ColumnCount; i )
{
ex.Cells[1, i 1] = dg.Columns[i].HeaderText;
}
for (int i = 0; i < dg.RowCount; i )
{
for (int j = 0; j < dg.ColumnCount; j )
{
ex.Cells[i 2, j 1] = dg[j, i].Value.ToString();
}
}
return true;
}
private void button4_Click(object sender, EventArgs e)
{
DataGridviewToExcel(dataGridView1,true);
}
private void button5_Click(object sender, EventArgs e)
{
DView();
}
private void comboBox1_SelectedIndexChanged(object sender, EventArgs e)
{
}
private void button6_Click(object sender, EventArgs e)
{
this.Close();
}
private void dataGridView1_CellContentClick(object sender, DataGridViewCellEventArgs e)
{
}
}
}
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