C# 2008C# Gestion des exceptions dans les classes
J'ai développé la classe ci-dessous. Je dois obtenir l'équilibre du serveur Web. Une fois cela fait, il rappellera dans mon application principale avec le résultat.
Cependant, parfois, le serveur Web échoue pour une raison inconnue. Pourrait être un volume élevé de trafic ou autre chose. Cependant, je n'ai pas implémenté de gestion des exceptions dans ma classe. Comme l'application qui utilise cela gère l'exception.
Cependant, le client a confirmé que lorsque le serveur Web échoue, il affiche une boîte de dialogue d'exception non gérée. Ensuite, ils doivent cliquer sur Continuer pour continuer à utiliser mon application. Donc, ci-dessous, je ne suis pas sûr si je devrais mettre en œuvre la gestion des exceptions dans ma classe. Cependant, je suis confus quant à savoir pourquoi l'exception n'a pas été interceptée dans mon application comme ci-dessous.
Un grand merci pour toutes les suggestions, ou si vous voyez quoi que ce soit d'autre mal,
private void OnGetBalanceCompleted(object sender, SIPPhoneLibraryEventArgs e)
{
try
{
//If the balance starts with 'null' there has been an error trying to get the balance.
if (e.Balance.StartsWith("null"))
{
statusDisplay1.CurrentBalance = CATWinSIP_MsgStrings.BalanceError;
}
else
{
// Display the current balance and round to 2 decimal places.
statusDisplay1.CurrentBalance = Math.Round(Convert.ToDecimal(e.Balance), 2).ToString();
//If the balance is zero display in the status message
if (decimal.Parse(e.Balance) == 0)
{
this.statusDisplay1.CallStatus = "Zero Balance";
}
}
//Remove the event as no longer needed
siplibrary.GetBalanceCompletedEvent -= new EventHandler<SIPPhoneLibraryEventArgs>(OnGetBalanceCompleted);
}
catch (WebException ex)
{
MessageBox.Show(ex.Message);
}
catch (Exception ex)
{
MessageBox.Show(ex.Message);
}
}
//Control library for all importing functions
public class Balance : IDisposable
{
//Constructor
WebClient wc;
public Balance()
{
using (wc = new WebClient())
{
//Create event handler for the progress changed and download completed events
wc.DownloadProgressChanged += new DownloadProgressChangedEventHandler(wc_DownloadProgressChanged);
wc.DownloadStringCompleted += new DownloadStringCompletedEventHandler(wc_DownloadStringCompleted);
}
}
~Balance()
{
this.Dispose(false);
}
//Event handler and the method that handlers the event
public EventHandler<SIPPhoneLibraryEventArgs> GetBalanceCompletedEvent;
//The method that raises the event
public void OnGetBalanceCompleted(SIPPhoneLibraryEventArgs e)
{
if (GetBalanceCompletedEvent != null)
{
GetBalanceCompletedEvent(this, e);
}
}
//Get the current balance for the user that is logged in.
//If the balance returned from the server is NULL display error to the user.
//Null could occur if the DB has been stopped or the server is down.
public void GetBalance(string sipUsername)
{
//Remove the underscore (_) from the username, as this is not needed to get the balance.
sipUsername = sipUsername.Remove(0, 1);
string strURL = string.Format("http://xxx.xxx.xx.xx:xx/voipbilling/servlet/advcomm.voipbilling.GetBalance?CustomerID={0}", sipUsername);
//Download only when the webclient is not busy.
if (!wc.IsBusy)
{
// Sleep for 1/2 second to give the server time to update the balance.
System.Threading.Thread.Sleep(500);
// Download the current balance.
wc.DownloadStringAsync(new Uri(strURL));
}
else
{
System.Windows.Forms.MessageBox.Show("Busy please try again");
}
}
//return and display the balance after the download has fully completed
void wc_DownloadStringCompleted(object sender, DownloadStringCompletedEventArgs e)
{
//Pass the result to the event handler
this.OnGetBalanceCompleted(new SIPPhoneLibraryEventArgs(e.Result));
}
//Progress state of balance.
void wc_DownloadProgressChanged(object sender, DownloadProgressChangedEventArgs e)
{
//Write the details to the screen.
Console.WriteLine(e.TotalBytesToReceive);
Console.WriteLine(e.BytesReceived);
Console.WriteLine(e.ProgressPercentage);
}
//Dispose of the balance object
public void Dispose()
{
Dispose(true);
GC.SuppressFinalize(this);
}
//Remove the event handlers
private bool isDisposed = false;
private void Dispose(bool disposing)
{
if (!this.isDisposed)
{
if (disposing)
{
wc.DownloadProgressChanged -= new DownloadProgressChangedEventHandler(wc_DownloadProgressChanged);
wc.DownloadStringCompleted -= new DownloadStringCompletedEventHandler(wc_DownloadStringCompleted);
wc.Dispose();
}
isDisposed = true;
}
}
}