捕获块错误

Question

I am working on a desktop application where when I thaught of handling the error in catch block in the Event Log then I am getting a error as

Error 3 The type or namespace name 'EventLog' could not be found (are you missing a using directive or an assembly reference?)

in this

catch (Exception ex)
{
    EventLog log = new EventLog("Application");
    log.Source = "MFDBAnalyser";
    log.WriteEntry(ex.Message);
}

waiting for suggestions.

Answer 1

Add to the top:

using System.Diagnostics;

or use directly:

catch (Exception ex)
{
    System.Diagnostics.EventLog log = new System.Diagnostics.EventLog("Application");
    log.Source = "MFDBAnalyser";
    log.WriteEntry(ex.Message);
}

or if you're using .NET 3.5 or 4.0 / VS 2008 or 2010 (the most preferred way):

catch (Exception ex)
{
    using (var log = new System.Diagnostics.EventLog("Application") { Source = "MFDBAnalyser" })
    {
        log.WriteEntry(ex.Message);
    }
}

• Keyword var reduces the code length.
• You should call Dispose() (or use using block) for classes implementing IDisposable !

Answer 2

Assuming System.dll has been referenced by your project (normally the case), you can solve this problem by either of :

• Importing the namespace, by adding a using System.Diagnostics; directive at the top of your file.
• Qualifying the type fully - System.Diagnostics.EventLog log = ...
• Providing an alias. Eg, by adding using EventLog = System.Diagnostics.EventLog; at the top of your file.

Answer 3

have you added a using directive to System.Diagnostics ?

If not, you will have to write it as System.Diagnostics.EventLog instead.

Answer 4

您应该将EventLog类库引用添加到引用System.Diagnostics