邮箱的删除邮件和垃圾管理

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

namespace Long5
{
public partial class Form1 : Form
{
public Form1()
{
InitializeComponent();
}

//收件箱的Click事件
private void toolStripButton1_Click_1(object sender, EventArgs e)
{
string sql = "select * from Mails where IsDelete=0";
try
{
SqlCommand command=new SqlCommand(sql,DBHelper.connection);
DBHelper.connection.Open();
SqlDataReader dataReader=command.ExecuteReader();
listView1.Items.Clear(); //清空收件箱的相同内容，避免重复
while (dataReader.Read())
{
ListViewItem item = new ListViewItem(dataReader["Receiver"].ToString());
item.Tag=(int)dataReader["id"];
listView1.Items.Add(item);
item.SubItems.AddRange(new string[] //循环读取和数据库中绑定的列的内容
{
dataReader["Acceptor"].ToString(),
dataReader["Subject"].ToString(),
dataReader["Date"].ToString(),
} );
}
dataReader.Close();
}
catch(Exception ex)
{
MessageBox.Show(ex.Message);
}
finally
{
DBHelper.connection.Close();
}
}

//垃圾箱的Click事件
private void toolStripButton2_Click(object sender, EventArgs e)
{
if (listView1.SelectedItems.Count == 0)
{
MessageBox.Show("请选中要删除的邮件", "提示");
}
else
{
DialogResult result = MessageBox.Show("确定要删除吗？", "提示",MessageBoxButtons.YesNo,MessageBoxIcon.Information);
if (result==DialogResult.Yes)
{
try
{
//查询数据库中的id列一行的内容
string sql = string.Format("select isdelete from Mails where id='{0}'", (int)listView1.SelectedItems[0].Tag);
SqlCommand command = new SqlCommand(sql,DBHelper.connection);
DBHelper.connection.Open();
bool isdelete = (bool)command.ExecuteScalar();
if (isdelete == false)
{
//更新数据库表的删除状态
string sql1 = string.Format("update Mails set isdelete=1 where id='{0}'", (int)listView1.SelectedItems[0].Tag);
command.CommandText = sql1; //重新指定sql语句，下同
int count = command.ExecuteNonQuery();
if (count > 0)
{
MessageBox.Show("删除成功，邮件存放于垃圾箱", "提示");
}
else
{
MessageBox.Show("删除失败", "提示");
}
}
else
{
string sql1 = string.Format("delete from Mails where id='{0}'", listView1.SelectedItems[0].Tag);
command.CommandText = sql1;
int count = command.ExecuteNonQuery();
if (count > 0)
{
MessageBox.Show("确定要彻底删除邮件吗？", "提示", MessageBoxButtons.OK, MessageBoxIcon.Information);
}
else
{
MessageBox.Show("删除失败", "提示");
}
}
}
catch(Exception ex)
{
MessageBox.Show(ex.Message);
}
finally
{
DBHelper.connection.Close();
}
}
}
}

//删除的Click事件
private void toolStripButton3_Click(object sender, EventArgs e)
{
listView1.Items.Clear();
try
{
string sql = string.Format("select * from Mails where isdelete=1");
SqlCommand command = new SqlCommand(sql,DBHelper.connection);
DBHelper.connection.Open();
SqlDataReader dataReader = command.ExecuteReader();
while(dataReader.Read())
{
ListViewItem listView = new ListViewItem(dataReader["Receiver"].ToString());
listView.Tag = (int)dataReader["id"];
listView1.Items.Add(listView);
listView.SubItems.AddRange(new string[]
{
dataReader["Acceptor"].ToString(),
dataReader["Subject"].ToString(),
dataReader["Date"].ToString()
} );
}
}
catch(Exception ex)
{
MessageBox.Show(ex.Message);
}
finally
{
DBHelper.connection.Close();
}
}

private void toolStripButton4_Click(object sender, EventArgs e)
{
this.Close();
}
}
}