Stepping through the examples
The easiest example to test is the ConnectionManagement quick start. This sample application allows you to simulate going on and off line. However, it only exercises the Connection management portion of the SCOAB. A more complete example is the Insurance Claims Client.

In the Insurance Claims example, rather than just testing for the presence of a network connection, you can actually see how changes to data are cached locally for transmission when the application can once again connect. The application allows you to download data to use locally while connected and then allows you to force the application offline, edit data and then reconnect and synchronize the changed data. Figure 2 shows the screen as an address is edited offline.

Figure 2. The Insurance Claims form while editing address offline

Given the current implementation of this example, if you were to exit the application before going online again, the changes would be lost. Again, it is important to remember that this is an implementation detail and not a limitation of the SCOAB. In the Insurance Claims example, the data on the "server" (the data that the application "downloads") is in an XML file. There is nothing preventing a program using the SCOAB from storing the changes in an XML file or even a database in the file system local to the application.

Some of the files used to download data in this example are:

App.Config � Specifies configuration information for the application. This is an interesting file, in that it exposes a number of the details of how the system can be expanded. One thing that is obvious is the extensive use of the Provider model.

Controller.cs - Manages the interaction between the connection manager and the service agents. It registers itself to get notification of connection state change. It also creates an InsuranceClaimsClientServiceAgent and registers with it to initiate the transfer of work items.

InsuranceClaimsClientServiceAgent.cs - Initiates upload and download of the Work item information.

OnlineProxy.cs - Interacts with the remote service. In the Insurance Claims example, this is a Web Service.

I looked at the C# version. There are corresponding Visual Basic.Net files as well.

The Web Service used by this example exposes two Web methods, DownloadWorkItems(), which returns a DataSet, and UpdateWorkItem(), which expects a DataSet as a parameter. The UpdateWorkItem() method uses the Update method on a DataSet with the server-side rows, passing in the modified work items. This is a reasonably simple implementation, and again, in the real world, you would need to provide a more robust solution. The Web.Config file has an appSettings section that allows the connection string to be configured.

Exploring ways to expand the Smart Client Online Application Block
As previously mentioned, the SCOAB makes extensive use of the provider model. There are a number of providers that can be written to allow different behaviors.