Tài liệu Updating Server Data Using a Web Service ppt

[ Team LiB ]

Recipe 4.11 Updating Server Data Using a Web Service

Problem

You want to update a data source using an XML web service and use the web service

from your client application.

Solution

Use a DataSet object.

The XML web service code contains two methods:

LoadOrders( )

Creates and returns a DataSet containing the Orders and Order Details tables from

Northwind and a DataRelation between those tables.

UpdateOrders( )

Takes a DataSet argument containing the changes made to the DataSet created by

the LoadOrders( ) method, creates two DataAdapter objects with

CommandBuilder generated update logic for each, and uses the DataAdapter

objects to update the Orders and Order Details tables in Northwind.

The client-side code contains two event handlers:

Form.Load

Sets up the example by calling the LoadOrders( ) method in the web service to

populate a DataSet. The default view of the Orders table is bound to the data grid

on the form.

Update Button.Click

Calls the UpdateOrders( ) method in the web service passing a DataSet containing

changes made to the DataSet since the form was loaded or since the last time the

UpdateOrders( ) method was called.

The C# code for the XML web service is shown in Example 4-25.