Figure 101 with zero denominator in .NET framework

Generating PDF417 in .NET framework Figure 101 with zero denominator
Figure 101 with zero denominator
PDF417 Generation In Visual Studio .NET
Using Barcode encoder for ASP.NET Control to generate, create PDF 417 image in ASP.NET applications.
returned by calling service
Barcode Encoder In .NET
Using Barcode generation for ASP.NET Control to generate, create bar code image in ASP.NET applications.
Finally, return the denominator to a nonzero value and call the service again Although the call would normally be successful, the call fails, receivwith a message similar to ing a Figure 102
Drawing PDF417 In Visual C#
Using Barcode printer for VS .NET Control to generate, create PDF417 image in Visual Studio .NET applications.
Figure 102 for faulted channel
Painting PDF-417 2d Barcode In .NET
Using Barcode generation for VS .NET Control to generate, create PDF417 image in Visual Studio .NET applications.
10: Exception Handling
PDF 417 Maker In VB.NET
Using Barcode printer for VS .NET Control to generate, create PDF-417 2d barcode image in VS .NET applications.
Because WCF received an unhandled exception at the service host, it assumed the exception was indicative of a fatal issue and therefore faulted , the established security the server channel In our case with session is no longer valid, so communications must be reestablished by recreating the client proxy
Painting EAN / UCC - 13 In Visual Studio .NET
Using Barcode maker for ASP.NET Control to generate, create GS1 128 image in ASP.NET applications.
NOTE
Generating Code 39 Full ASCII In VS .NET
Using Barcode creator for ASP.NET Control to generate, create Code 39 Full ASCII image in ASP.NET applications.
One-Way Operations and Faults
Generating Barcode In Visual Studio .NET
Using Barcode maker for ASP.NET Control to generate, create barcode image in ASP.NET applications.
Operations with one-way designations by design do not receive a message from the called service, regardless of whether that call was successful Because no message is returned, there is no indication to the client that a fault has occurred In addition, if that fault was caused by an unhandled exception, the server channel will be considered faulted, but the client will not be aware of that fact In a session-dependent interaction, continued calls ) until the proxy will fail (with is re-created Be certain to account for this behavior in your client and server logic when utilizing one-way operations
Bar Code Encoder In VS .NET
Using Barcode drawer for ASP.NET Control to generate, create bar code image in ASP.NET applications.
Detecting and Recovering a Faulted Channel Faulted channels can and should be detected by the client Client code should inspect the channel after each fault to determine whether that fault resulted in faulting of the channel itself This can be done by having the property in exception-handling code client code check the channel s as shown in Listing 103
Barcode Encoder In VS .NET
Using Barcode maker for ASP.NET Control to generate, create bar code image in ASP.NET applications.
Listing 103 Verifying a Channel Is Not Faulted
ANSI/AIM Code 128 Printer In VS .NET
Using Barcode creator for ASP.NET Control to generate, create Code 128 Code Set A image in ASP.NET applications.
Communicating Exception Details
USD - 8 Creation In Visual Studio .NET
Using Barcode maker for ASP.NET Control to generate, create USD - 8 image in ASP.NET applications.
If a faulted state is detected, you should log the conditions and cause, attempt to re-create the proxy, and continue When that is not feasible, such as when a session was underway that you cannot manually re-create, the user should be noti ed and further calls with that proxy prevented
ECC200 Generation In .NET Framework
Using Barcode drawer for .NET Control to generate, create Data Matrix image in .NET framework applications.
Communicating Exception Details
Code 3 Of 9 Creator In VB.NET
Using Barcode creator for VS .NET Control to generate, create Code39 image in Visual Studio .NET applications.
In the earlier example, we called a service that raised an unhandled exception to the service layer, and the client received the minimal information shown in Figure 101 By default, WCF relays this message, rather than details about an exception, to a caller to prevent exposure of sensitive details about the system s implementation or infrastructure has an property that can be used to enable transmission of exception details to the le to be client To enable this behavior, modify your project s similar to Listing 104
Bar Code Generator In .NET Framework
Using Barcode generator for .NET framework Control to generate, create barcode image in VS .NET applications.
Listing 104 Enabling Option via Configuration
Code 3 Of 9 Printer In Java
Using Barcode printer for Java Control to generate, create Code 3 of 9 image in Java applications.
10: Exception Handling
Make Bar Code In Java
Using Barcode creator for Java Control to generate, create barcode image in Java applications.
Listing 104 continued
Bar Code Creator In .NET
Using Barcode printer for .NET framework Control to generate, create bar code image in .NET framework applications.
After the option has been enabled, run the sample service again and supply a zero denominator, which will result in the message shown in Figure 103
Barcode Recognizer In Java
Using Barcode recognizer for Java Control to read, scan read, scan image in Java applications.
Figure 103 Exception detail included with
Reading Code-39 In Visual Studio .NET
Using Barcode scanner for .NET framework Control to read, scan read, scan image in .NET framework applications.
also set this behavior by using the on the service de nition For example, we could enable the communication of debugging information by modifying the Servicecs de nition to Listing 105
Listing 105 Using to Enable
Note
that
Managing Ser vice Exceptions with
Note that using the attribute in this manner to enable exception detail will override any other settings in the con guration that may be intended to disable the feature Therefore, we recommend you use a con gurationbased approach for production applications, perhaps reserving the attribute usage for development purposes Whether you elect con guration- or attribute-based use of this feature, remember to disable the option when you do not actively require the details to be transmitted Using this option only when necessary will help you to ensure that sensitive service details are not exposed
Managing Service Exceptions with
The rst example demonstrated the effect of allowing an unhandled exception to rise through the service implementation layers to the service host Notice that in Figure 101, the type of exception returned to the caller is This is a base -derived type used in WCF to integrate with the SOAP fault speci cation By default, exceptions that reach the service host that are not derived are considered indications of a potentially fatal confrom and the original dition The exception is replaced by a exception s details are omitted unless the option is enabled The is then serialized as a SOAP fault for communication back to the caller (save for one-way invocations) Again, if the call was part of a session, that session will be destroyed and will need to be re-created The fatal condition created by unhandled exceptions can be prevented by catching exceptions before they reach the service host and throwing a manually The class has a number of