C#2008C#取消後臺工作
我使用下面的代碼登錄到一個軟電話的DoWork的。但是,登錄過程是一個漫長的過程,因爲有很多事情必須進行初始化和檢查,我只在這裏放了一些,因爲它會使代碼長時間發佈。
在下面的代碼中,我檢查CancellationPending是否在取消按鈕單擊事件中調用了CancelAsync,然後再執行每次檢查。它是否正確?此外,如果檢查失敗,我還會調用CancelAsync並將e.Cancel設置爲true。
我想知道我的方法,我在這裏使用的是最好的方法來使用。
非常感謝任何建議,
private void bgwProcessLogin_DoWork(object sender, DoWorkEventArgs e)
{
/*
* Perform at test to see if the background worker has been
* cancelled by the user before attemping to continue to login.
*
* Cancel background worker on any failed attemp to login
*/
// Start with cancel being false as to reset this if cancel has been set to true
// in the cancel button.
e.Cancel = false;
NetworkingTest connection_test = new NetworkingTest();
if (!this.bgwProcessLogin.CancellationPending)
{
// Check local LAN or Wireless connection
if (!connection_test.IsNetworkConnected())
{
// Update label
if (this.lblRegistering.InvokeRequired)
{
this.lblRegistering.Invoke(new UpdateRegisterLabelDelegate(UpdateRegisterLabel), "No network connection");
}
else
{
this.lblRegistering.Text = "No network connection";
}
// Failed attemp
this.bgwProcessLogin.CancelAsync();
e.Cancel = true;
return;
}
// Report current progress
this.bgwProcessLogin.ReportProgress(0, "Network connected");
}
else
{
// User cancelled
e.Cancel = true;
return;
}
// Test if access to Server is available
if (!this.bgwProcessLogin.CancellationPending)
{
if (!connection_test.IsSIPServerAvailable())
{
// Update label
if (this.lblRegistering.InvokeRequired)
{
this.lblRegistering.Invoke(new UpdateRegisterLabelDelegate(UpdateRegisterLabel), "Server unavailable");
}
else
{
this.lblRegistering.Text = "Server unavailable";
}
// Failed attemp
this.bgwProcessLogin.CancelAsync();
e.Cancel = true;
return;
}
// Report current progress
this.bgwProcessLogin.ReportProgress(1, "Server available");
}
else
{
// User cancelled
e.Cancel = true;
return;
}
.
.
.
}
private void bgwProcessLogin_RunWorkerCompleted(object sender, RunWorkerCompletedEventArgs e)
{
// Check for any errors
if (e.Error == null)
{
if (e.Cancelled)
{
// User cancelled login or login failed
}
else
{
// Login completed successfully
}
}
else
{
// Something failed display error
this.statusDisplay1.CallStatus = e.Error.Message;
}
}
private void bgwProcessLogin_ProgressChanged(object sender, ProgressChangedEventArgs e)
{
this.lblRegistering.Text = e.UserState.ToString();
}
private void btnCancel_Click(object sender, EventArgs e)
{
// Cancel the logging in process
this.bgwProcessLogin.CancelAsync();
this.lblRegistering.Text = "Logged out";
}
很好的答案。我希望這也能在Silverlight中起作用。原來這不是因爲安全限制。調用`Thread.Abort()`將從Silverlight 4(http://msdn.microsoft.com/en-us/library/ty8d3wta(v=VS.95).aspx)開始引發MethodAccessException。哦,這仍然是一個很好的答案。 – 2011-10-05 23:45:43