根据客户的要求，我编写了一个继承自 webclient 的通信类。他们希望能够“将自定义窗口表单作为进度条传递”，而不是我创建了一个实现 3 个属性的接口。无论如何，我遇到的问题是应用程序启动，我点击开始按钮可以这么说，我第一次这样做时，ui线程被冻结，几秒钟后它解冻并且进度条和数据开始下降。
但是，在最初的冻结之后，任何后续按下开始按钮都可以正常工作并且不会阻止线程任何想法？
以下是表格 1 中的相关代码
private void btnSubmit_Click(object sender, EventArgs e)
{
txtResponse.Text = "";
progressForm = new ProgressFormTest();
myCommunication = new CommunicationClient(progressForm);
myCommunication.DownloadStringCompleted += new DownloadStringCompletedEventHandler(wc_RequestComplete);
// myCommunication.DownloadProgressChanged += new DownloadProgressChangedEventHandler(wc_DownloadProgressChanged);
myCommunication.Timeout += new EventHandler(wc_TimeOut);
myCommunication.Cancelled += new EventHandler(myCommunication_Cancelled);
progressForm.Show();
myCommunication.TimeoutValue = (int)numConnectionTimeout.Value * 1000;
myCommunication.DownloadStringAsync(new Uri(txtUrl.Text));
}
这里是交流课
public class CommunicationClient:WebClient
{
private int step = 1000;
private long bytesReceived;
private long bytesSent;
private Status status;
private System.Timers.Timer _timer;
private IProgress myProgressForm;
/// <summary>
/// Sets the timeout value in milliseconds
/// </summary>
public int TimeoutValue { get; set; }
public int TimeElapsed { get; set; }
public long BytesReceived
{
get
{
return bytesReceived;
}
}
public long BytesSent
{
get
{
return bytesSent;
}
}
public event EventHandler Timeout;
public event EventHandler Cancelled;
public CommunicationClient(IProgress progressForm)
{
myProgressForm = progressForm;
_timer = new System.Timers.Timer(step);
_timer.Elapsed += new ElapsedEventHandler(timer_Elapsed);
}
protected override void OnDownloadStringCompleted(DownloadStringCompletedEventArgs e)
{
_timer.Stop();
if (status == Status.Completed)
{
myProgressForm.PercentComplete = 100;
base.OnDownloadStringCompleted(e);
}
}
protected override void OnDownloadProgressChanged(DownloadProgressChangedEventArgs e)
{
bytesReceived = e.BytesReceived;
myProgressForm.BytesReceived = bytesReceived;
if (e.TotalBytesToReceive == -1)
myProgressForm.PercentComplete = calculateFakePercentage();
else
myProgressForm.PercentComplete = e.ProgressPercentage;
base.OnDownloadProgressChanged(e);
}
protected virtual void OnTimeout(EventArgs e)
{
if (Timeout != null)
{
CancelAsync();
this.Dispose();
Timeout(this, e);
}
}
protected virtual void OnCancelled(EventArgs e)
{
if (Cancelled != null)
{
this.Dispose();
Cancelled(this, e);
}
}
/// <summary>
/// Cancels a pending asynchronous operation and raises the Cancelled Event
/// </summary>
/// <param name="Event">Set to true to raise the event</param>
public void CancelAsync(bool Event)
{
CancelAsync();
if (Event)
{
status = Status.Cancelled;
OnCancelled(new EventArgs());
}
}
private void initialize()
{
status = Status.Completed;
TimeElapsed = 0;
_timer.Start();
}
new public void DownloadStringAsync(Uri url)
{
initialize();
base.DownloadStringAsync(url);
}
private void timer_Elapsed(object sender, ElapsedEventArgs e)
{
TimeElapsed += step;
if (TimeElapsed >= TimeoutValue)
{
_timer.Stop();
status = Status.Timeout;
OnTimeout(e);
}
}
//used when the website in question doesnt provide the content length
private int calculateFakePercentage()
{
return (int)bytesReceived * 100 / 60000 ;
}
}
这是简单的接口 IProgressForm
public interface IProgress
{
int PercentComplete
{
get;
set;
}
long BytesReceived
{
get;
set;
}
long BytesSent
{
get;
set;
}
}