C# 2008
我正在使用以下代码登录软电话。然而,由于有许多需要初始化和检查的内容,登录过程是一个长过程,我仅在此处放了一些内容,因为它会使代码变得太长。
在下面的代码中,我在每个检查之前检查CancellationPending是否已在我的取消按钮单击事件中调用CancelAsync。这样做是否正确?如果检查失败,我还会调用CancelAsync并将e.Cancel设置为true。
我想知道我在这里使用的方法是否是最佳方法。
非常感谢任何建议,
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";
}
Thread.Abort()
会抛出MethodAccessException异常(http://msdn.microsoft.com/en-us/library/ty8d3wta(v=VS.95).aspx)。不过,这仍然是一个好答案。 - Steve Wortham