Step 3: Specifying Local or WCF Data Access

There are several different ways you can specify which type of data access classes your business objects use to retrieve and manipulate data.

• You can add a DefaultDataAccessMode setting to your app.config or web.config file as shown here (currently, the only valid values are "local", "wcf" and "webservice") and set it to "wcf":

    <appSettings>
       <!-- Specifies the default data acccess model: "local", "wcf" or "webservice" -->
       <add key="DefaultDataAccessMode" value="wcf" />
     </appSettings>

• You can set mmAppBase.DefaultDataAccessMode programatically when your application first starts up.

  For example, you may want to add an option to a Windows User Login form that allows the user to specify whether they want to connect locally or remotely:

  

  In the handler for the radio buttons you can place code that sets the application's default access mode:

  private void rdoLocalData_CheckedChanged(object sender, EventArgs e)
  {
  	mmAppBase.DefaultDataAccessMode = mmDataAccessMode.Local;
  }
  
  private void rdoRemoteData_CheckedChanged(object sender, EventArgs e)
  {
  	mmAppBase.DefaultDataAccessMode = mmDataAccessMode.WCF;
  }

• You can also override a specific business object's CreateDataAccessObject() method to instantiate one or the other type of data access class.