qr code generator c# mvc Instrumentation in C#.NET

Generation QR Code ISO/IEC18004 in C#.NET Instrumentation

10
QR Creator In Visual C#
Using Barcode creator for Visual Studio .NET Control to generate, create QR image in VS .NET applications.
www.OnBarcode.com
Decoding Quick Response Code In C#.NET
Using Barcode recognizer for .NET Control to read, scan read, scan image in VS .NET applications.
www.OnBarcode.com
Instrumentation
Generate Bar Code In C#.NET
Using Barcode drawer for .NET framework Control to generate, create bar code image in VS .NET applications.
www.OnBarcode.com
Decode Bar Code In Visual C#
Using Barcode decoder for .NET framework Control to read, scan read, scan image in .NET framework applications.
www.OnBarcode.com
Provide an easy mechanism for users to check on the state of applications that are running
Encoding QR Code JIS X 0510 In VS .NET
Using Barcode generation for ASP.NET Control to generate, create Denso QR Bar Code image in ASP.NET applications.
www.OnBarcode.com
Paint Denso QR Bar Code In VS .NET
Using Barcode maker for .NET Control to generate, create QR Code ISO/IEC18004 image in .NET applications.
www.OnBarcode.com
Figure 10-1 shows the Event Viewer in Windows XP.
Encode QR In Visual Basic .NET
Using Barcode drawer for .NET framework Control to generate, create QR-Code image in .NET applications.
www.OnBarcode.com
Drawing PDF 417 In Visual C#.NET
Using Barcode generator for VS .NET Control to generate, create PDF 417 image in VS .NET applications.
www.OnBarcode.com
Figure 10-1
Barcode Creation In C#
Using Barcode drawer for .NET framework Control to generate, create bar code image in .NET framework applications.
www.OnBarcode.com
Matrix 2D Barcode Printer In Visual C#.NET
Using Barcode creation for VS .NET Control to generate, create Matrix Barcode image in Visual Studio .NET applications.
www.OnBarcode.com
The Windows XP Event Viewer
Creating Code 39 Extended In C#.NET
Using Barcode generator for .NET Control to generate, create USS Code 39 image in Visual Studio .NET applications.
www.OnBarcode.com
Uniform Symbology Specification Code 93 Creator In Visual C#.NET
Using Barcode generator for .NET framework Control to generate, create Code 93 Extended image in .NET applications.
www.OnBarcode.com
The creators of the Framework gave developers multiple tools to create and manage event log entries. Although the event logging mechanism is elegant and simple, you should keep in mind the old clich that states, There s no such thing as a free lunch. Accordingly, a few points need to be made before any responsible instruction on the use of event logs can take place. The MSDN documentation (which can be found at http://msdn2.microsoft.com/en-US/library/system.diagnostics.eventlog(VS.80).aspx) includes the following caveats:
Encoding Code 128 Code Set B In None
Using Barcode encoder for Online Control to generate, create Code 128C image in Online applications.
www.OnBarcode.com
Draw Code 128A In None
Using Barcode creator for Software Control to generate, create Code128 image in Software applications.
www.OnBarcode.com
Creating an EventLog object, writing to it, and passing it to code executing in a partial trust setting can be a huge security vulnerability. EventLog objects, including EventLogEntry objects and EventLogEntryCollection objects, should never be passed to less trusted code. This means any less trusted code, so it s important to be cognizant of the security context these objects are executing in. The EventLogPermission is required for many actions that use EventLog manipulation. Granting this permission to partially trusted code can open a serious security vulnerability. For example, mischievous code running in a partial trust environment with this permission granted could easily spoof other
Generate 1D Barcode In Java
Using Barcode creation for Java Control to generate, create 1D Barcode image in Java applications.
www.OnBarcode.com
PDF 417 Scanner In None
Using Barcode reader for Software Control to read, scan read, scan image in Software applications.
www.OnBarcode.com
Lesson 1: Logging Events
Decode Data Matrix 2d Barcode In Java
Using Barcode recognizer for Java Control to read, scan read, scan image in Java applications.
www.OnBarcode.com
QR Code 2d Barcode Generation In None
Using Barcode printer for Software Control to generate, create QR Code ISO/IEC18004 image in Software applications.
www.OnBarcode.com
applications. It could, for example, shut down a critical antivirus or spywaredetection application yet make it appear as if it s still running. The potential for mischief is unlimited.
Making Code-128 In None
Using Barcode creation for Office Excel Control to generate, create Code 128 Code Set B image in Excel applications.
www.OnBarcode.com
QR Code ISO/IEC18004 Maker In None
Using Barcode printer for Microsoft Word Control to generate, create QR-Code image in Word applications.
www.OnBarcode.com
Reading and logging events are relatively resource intensive in terms of disk utilization, system processor time, and other resources. EventLog objects can also get filled up, at which point attempts to write to them will cause exceptions to be thrown. EventLog objects should be used as necessary, but judiciously as well.
CAUTION Avoid EventLog objects in partial trust environments
Use of EventLog objects in a partial trust environment can cause serious security holes and should be avoided if at all possible.
With these warnings and caveats stated, let s look at the benefits of using EventLog objects.
Creating and Deleting an Event Log
To create an event log, the .NET Framework provides the EventLog class. To use it, the Source property needs to be specified and a message needs to be written, as shown in the following code, which requires the System.Diagnostics namespace:
' VB Public Shared Sub CreateEventLog() Dim DemoLog As New EventLog("Chap10Demo") DemoLog.Source = "Chap10Demo" DemoLog.WriteEntry("CreateEventLog called", EventLogEntryType.Information) End Sub // C# public static void CreateEventLog() { EventLog DemoLog = new EventLog("Chap10Demo"); DemoLog.Source = "Chap10Demo"; DemoLog.WriteEntry("CreateEventLog called", EventLogEntryType.Information); }
After you create an EventLog object and specify its source (which, by the way, can all be done in one of the overloaded constructors), information about the object should be visible from the Windows Event Viewer. Figure 10-2 shows what should be in the EventLog after successful execution of this code.
10
Instrumentation
Figure 10-2 The Windows Event Viewer after the Chap10Demo application has been created and written to
Deleting an event log is equally simple. You may want, for example, to delete the log that you just created as part of this exercise. To remove the demonstration log, use the Delete method of EventLog in code like the following:
' VB Public Shared Sub DeleteEventLog() EventLog.Delete ("Chap10Demo") End Sub // C# Public static void DeleteEventLog() { EventLog.Delete("Chap10Demo"); }
Just be sure you don t delete a log with valuable information by using this method!
Writing to an Event Log
Now that you have the code in place to create the log, it s time to use it. Only one small enhancement needs to be made to the code sample you just created to get it to write to the event log:
' VB Public Shared Sub CreateEventLog() Dim DemoLog As New EventLog("Chap10Demo") DemoLog.Source = "Chap10Demo" DemoLog.WriteEntry("CreateEventLog called", End Sub
EventLogEntryType.Information)
Lesson 1: Logging Events
// C# public static void CreateEventLog() { EventLog DemoLog = new EventLog("Chap10Demo"); DemoLog.Source = "Chap10Demo"; DemoLog.WriteEntry("CreateEventLog called", EventLogEntryType.Information); }
In this example, the WriteEntry method looks rather simple. However, there are 10 overloads for it. As is the case with many overloaded constructors, the minimal construction can be used and then you can set all necessary properties. Or you can specify all the information you need in the constructor. Although doing everything in the overload is typically considered more elegant and straightforward, you might encounter situations in which this approach won t work well with the rest of your code. For example, you might not know the rest of the values that you intend to record. To make the point a little clearer, here are each of the overloads in action:
' VB Public Shared Sub CreateEventLog() Dim DemoLog As New EventLog("Chap10Demo") DemoLog.Source = "Chap10Demo" DemoLog.WriteEntry("CreateEventLog called", End Sub
EventLogEntryType.Information)
// C# public static void CreateEventLog() { EventLog DemoLog = new EventLog("Chap10Demo"); DemoLog.Source = "Chap10Demo"; DemoLog.WriteEntry("CreateEventLog called", EventLogEntryType.Information); }
The following example shows how to use an overload to add an event ID:
' VB Public Shared Sub CreateEventLog() Dim DemoLog As New EventLog("Security") DemoLog.Source = "Chap10Demo" DemoLog.WriteEntry("CreateEventLog called", End Sub // C# public static void CreateEventLog() { EventLog DemoLog = new EventLog("Security"); DemoLog.Source = "Chap10Demo"; DemoLog.WriteEntry("CreateEventLog called", }
EventLogEntryType.Information, 100)
EventLogEntryType.Information, 100);
Copyright © OnBarcode.com . All rights reserved.