Visual CSharp 1002005 A Developers Notebook [Electronic resources] نسخه متنی

5.3. Create Master Detail Records

The Orders table is great, but when you look at an
order, you want to look at the details of that order as well. The
Northwind database establishes a parent-child relationship between
each record in the Orders table and one or more orders in the Order
Details table. You can reflect that in your application, again with
no code.

5.3.1. How do I do that?

Begin by creating a copy of the previous project (using Windows
Explorer) and renaming it MasterDetails. Change
the name of the solution, the project, and the form.

Open the Data Sources view, right-click NorthwindDataSet, and choose
Configure DataSet with Wizard, as shown in Figure 5-20.

Open the Tables in the Data Set, add the Order Details table, and
click Finish.

The data set is updated with relation objects based on the
appropriate columns; you do not have to write the code to create this
relation. Return to the form and reposition half of the controls to
the upper half of the form to make room for displaying the order
details.

Expand the Orders table. The last node is an
OrderDetails node. Drag that onto the form to
create a data grid. Hey! Presto! Instant master/detail records!

5.3.2. What just happened?

Not only was the grid added to your form, but two new controls were
added as well:
order_DetailsBindingSource and
order_detailsTableAdapter.

In addition, code is added to your .cs file to
manage filling the two components: one for the order and the other
for the order details, as shown in Example 5-2.

Example 5-2. Code added by the Designer

private void Form1_Load(object sender, EventArgs e)
{
this.order_DetailsTableAdapter.Fill
(this.northwindDataSet.Order_Details);
this.ordersTableAdapter.Fill(this.northwindDataSet.Orders);
}

Enter the customer ID and run the application. Not only is the order
shown, but all the related data from the Order Details table is
automatically synchronized to the appropriate order, as shown in
Figure 5-21.

5.3.3. What about...

...if I want to change the appearance of the details?

You have numerous options. The easiest is to click the smart tag for
the grid and then to click Auto Format, as shown in Figure 5-22.

In addition, you can add or remove columns or change the headers of
the columns through the smart tag. You can set other properties
through the properties window, and you can respond to dozens of
events to interrupt the process and massage either the data or its
display in any way you want.

5.3.4. Where can I learn more?

Try the walkthrough
"Displaying Related Data on a Windows
Form" on the MSDN site.