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Walkthrough: Exposing and Consuming an OData Service in LightSwitch

  • Artigo

LightSwitch applications can expose their data as an Open Data (OData) service that can be consumed by any application that supports the OData protocol. This walkthrough demonstrates how to expose data from one LightSwitch application and then consume that data in a second LightSwitch application.

Create a Host Application

The first step is to create a host application that exposes an OData feed.

To create a host application project

  1. On the menu bar, choose File, New Project.

  2. In the Installed Templates list, expand the Visual Basic or Visual C# node, choose LightSwitch Application (Visual Basic) or LightSwitch Application (Visual C#).

  3. In the Name field, enter Contact Host, and then choose the OK button.

  4. In Solution Explorer, open the shortcut menu for Properties and choose Open.

  5. Choose the Application Type tab, and, under Client, choose Web.

    Only web applications can expose their data as a service.

To add a data source

  1. In Solution Explorer, choose Data Sources.

  2. On the Project menu, choose Add Table.

  3. In the Properties window, choose the Name property, and then enter Contact.

  4. In the data designer, add the following fields:

    Name

    Type

    Required

    Name

    String

    True

    Phone

    Phone Number

    False

    Email

    Email Address

    False

To expose the service

  1. On the menu bar, choose Debug, Start Debugging.

    The Contact Host application opens in a browser window.

  2. Copy the first part of the URL (https://localhost:#####/).

    Leave the application running. It must be running to expose the service.

Create a Client Application

The next step is to create an application that will consume the OData service

To create a client project

  1. Open a new instance of Visual Studio.

  2. On the menu bar, choose File, New Project.

  3. In the Installed Templates list, choose LightSwitch Application (Visual Basic) or LightSwitch Application (Visual C#).

  4. In the Name field, enter Contact Client, and then choose the OK button.

To add a data source

  1. In Solution Explorer, choose Data Sources.

  2. On the menu bar, choose Project , Add Data Source.

  3. In the Attach Data Source Wizard, choose OData Service, and then choose the Next button.

  4. In the OData Source Address field, paste the URL that you copied from the Contact Host application (https://localhost:#####/), and then enter ContactData.svc after the last backslash (https://localhost:#####/ApplicationData.svc).

  5. Choose the Test Connection button.

  6. In the Test Connection dialog box, choose Contacts in the list, and then choose the Test button.

    After a brief delay, a Test connection succeeded dialog box should appear.

  7. Click the OK button, then choose the Close button to dismiss the dialog boxes, and then click the Next button.

  8. Expand the Entities node, choose Contacts, and then choose the Finish button.

    The data designer opens and displays the schema of the table that you created in the Contact Host project.

To add a screen

  1. In Solution Explorer, choose Screens.

  2. On the menu bar, choose Project , Add Screen.

  3. In the Add New Screen dialog box, choose Editable Grid Screen.

  4. In the Screen Data list, choose ApplicationDataData.Contacts, and then choose the OK button.

At this point, you can run the application and enter data. Any data that you enter is saved in the intrinsic database of the Contact Host project.

Next Steps

This walkthrough demonstrates consuming OData in the design time environment. After you publish the Contact Host application to a server that's running Internet Information Services (IIS) or to Microsoft Azure, you must update the OData Source Address for the client application to match the URL for the published application.

Note

If you close the Contact Host application in the design time environment and restart it, the LocalHost URL will change, and you will need to update the OData Source Address in the client project.

To update the data source

  1. Open the Contact Client project.

  2. In Solution Explorer, choose ApplicationDataData.

  3. On the menu bar, choose Project , Update Datasource.

  4. In the Attach Data Source Wizard, choose the Previous button.

  5. In the OData Source Address text box, enter the new URL for the published Contact Host application (for example, https://www.contoso.com/ApplicationData.svc).

  6. Click the Next button, and then click the Finish buttton to update the data source.

See Also

Concepts

Exposing LightSwitch Application Data