7.1. Binding Simple Data to Web Forms Controls
Problem
You need to bind a field of data to a server-side control.
Solution
Use the DataBind( )
method.
The Web Forms page sample code displays the company name for the
CustomerID specified by assigning the method GetCompanyName( )
, which is defined in the code-behind file, to the
Text
property of TextBox
control companyNameTextBox
. The code for the Web
Forms page is shown in Example 7-1.
Example 7-1. File: ADOCookbookCS0701.aspx
<asp:TextBox id="companyNameTextBox" style="Z-INDEX: 103; LEFT: 136px;
POSITION: absolute; TOP: 128px" runat="server" ReadOnly="True"
Width="280px" Text="<%# GetCompanyName(customerIdTextBox.Text) %>
">
</asp:TextBox>
The code-behind contains one event and one method:
Page.Load
Binds data from the source—in this case the
GetCompanyName( )
method—to thecompanyNameTextBox
server control.GetCompanyName( )
This method retrieves and returns the company name for a specified customer ID.
The C# code for the code-behind is shown in Example 7-2.
Example 7-2. File: ADOCookbookCS0701.aspx.cs
// Namespaces, variables, and constants using System; using System.Configuration; using System.Data; using System.Data.SqlClient; // . . . private void Page_Load(object sender, System.EventArgs e) { companyNameTextBox.DataBind( ); } public String GetCompanyName(String customerId) { String companyName = "Not found."; if (customerIdTextBox.Text != "") { // Create a command to retrieve the company name for the // user-specified customer ID. String ...
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