这个问题来自社区提问，代码保留一份用来以后回答
using
System;
using
System.ComponentModel;
using
System.Windows.Forms;
namespace
WindowsApplication4
{
///
<summary>
///
gui类
///
</summary>
public
partial
class
Form1:Form
{
public
Form1()
{
InitializeComponent();
}
private
void
button1_Click(
object
sender,EventArgse)
{
//
用子线程工作
new
System.Threading.Thread(
new
System.Threading.ThreadStart(StartDownload)).Start();
}
//
开始下载
public
void
StartDownload()
{
Downloaderdownloader
=
new
Downloader();
downloader.onDownLoadProgress
+=
new
Downloader.dDownloadProgress(downloader_onDownLoadProgress);
downloader.Start();
}
//
同步更新ui
void
downloader_onDownLoadProgress(
long
total,
long
current)
{
if
(
this
.InvokeRequired)
{
this
.Invoke(
new
Downloader.dDownloadProgress(downloader_onDownLoadProgress),
new
object
[]
{total,current}
);
}
else
{
this
.progressBar1.Maximum
=
(
int
)total;
this
.progressBar1.Value
=
(
int
)current;
}
}
}
///
<summary>
///
下载类
///
</summary>
public
class
Downloader
{
//
委托
public
delegate
void
dDownloadProgress(
long
total,
long
current);
//
事件
public
event
dDownloadProgressonDownLoadProgress;
//
开始模拟工作
public
void
Start()
{
for
(
int
i
=
0
;i
<
100
;i
++
)
{
if
(onDownLoadProgress
!=
null
)
onDownLoadProgress(
100
,i);
System.Threading.Thread.Sleep(
100
);
}
}
}
}
