一、BackGroundWorker工作步骤
1.向窗体中拖入一个BackGroundWorker控件。
2.在某个方法或者事件中,调用BackGroundWorker的RunWorkerAsync()方法。
3.该方法为异步操作,将自动引发BackGroundWorker的DoWork事件。
4.调用ReportProgress方法将引发ProgressChanged事件。
二、一个使用了BackGroundWorker的例子
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Text;
using System.Windows.Forms;
using System.Threading;
using System.Data.SqlClient;
//该用例需要一个名为bgwTestDB的Sql Server数据库
//数据库中应包含tbBgwTest表。
//表中有data1、data2两列。
//数据库中还需要一个存储过程,sql语句如下:
/***************
create procedure insertOneData
@data1 nchar(10),
@data2 int
as
insert into tbBgwTest (data1,data2) values (@data1, @data2)
********************/
namespace winBackgroundWorkerTest
{
public partial class backgroundWorkerTest : Form
{
int count = 30;
public backgroundWorkerTest()
{
InitializeComponent();
}
private void btnAdd_Click(object sender, EventArgs e)
{
//1.调用bgwInsertData的RunWorkerAsync方法,用来引发DoWork事件
bgwInsertData.RunWorkerAsync(count);
}
private void bgwInsertData_DoWork(object sender, DoWorkEventArgs e)
{
BackgroundWorker worker = sender as BackgroundWorker;
//2.在DoWork中调用自定义函数,并将引发DoWork事件的sender传递出去
insertData(worker);
}
private void bgwInsertData_ProgressChanged(object sender, ProgressChangedEventArgs e)
{
progressBar1.Value = e.ProgressPercentage;
}
//自定义函数 insertData()
private void insertData(BackgroundWorker worker)
{
SqlConnection conn = new SqlConnection(@"Data Source=.\sqlexpress;Initial Catalog=bgwTestDB;Integrated Security=True");
SqlCommand cmd = new SqlCommand("insertOneData", conn);
cmd.CommandType = CommandType.StoredProcedure;
cmd.Parameters.Add("data1", SqlDbType.NChar, 10);
cmd.Parameters.Add("data2", SqlDbType.Int);
for (int i = 0; i < count; i++)
{
try
{
conn.Open();
cmd.Parameters["data1"].Value = i + 1;
cmd.Parameters["data2"].Value = i + 1;
cmd.ExecuteNonQuery();
//3.调用worker的ReportProgress函数,用来引发事件ProgressChanged
worker.ReportProgress(i, worker);
}
catch(Exception ex)
{
MessageBox.Show(ex.Message);
}
finally
{
if (conn.State == ConnectionState.Open)
conn.Close();
}
Thread.Sleep(50);
}
}
private void bgwInsertData_RunWorkerCompleted(object sender, RunWorkerCompletedEventArgs e)
{
if (e.Error != null)
{
MessageBox.Show(e.Error.Message, "提示", MessageBoxButtons.OK, MessageBoxIcon.Error);
return;
}
else if (e.Cancelled)
{
MessageBox.Show("取消操作!", "提示", MessageBoxButtons.OK, MessageBoxIcon.Information);
return;
}
else
MessageBox.Show("操作成功!", "提示", MessageBoxButtons.OK, MessageBoxIcon.Information);
}
}
}