Tài liệu Hyperlink from a Row in the Data Grid to a Detail Page ppt

5.8 Hyperlink from a Row in the Data Grid to a Detail Page Often, I need to zero in and display data based on a record in the DataGrid control. How do I display detail information in a separate page from a DataGrid control? Technique One of the types of columns that you can use in the data grid is the HyperLink column. This column makes it fairly easy to link pages based on data. To see how the HyperLink type column is used in this How-To, take a look at Figure 5.14. Figure 5.14. No code is required for link pages based on data. By your specifying the URL Field to be ProductID and URL Format String to be wfrmHowTo5_8b.aspx?ID={0}, the data grid automatically calls the wfrmHowTo5_8b.aspx and passes the ProductID to the form when you click on a product. Steps Open and run the Visual Basic .NET-Chapter 5 solution. From the main page, click on the hyperlink with the caption How-To 5.8: Hyperlink From a Row in the Data Grid to a Detail Page. You then see all the products loaded into a data grid. Notice that the products are actually hyperlinks (see Figure 5.15). Figure 5.15. These hyperlinks require no code to call a detail page. When you click on a product, another page is displayed, with detail information supplied (see Figure 5.16). 1. Create a Web Form. Then place the controls in Table 5.12 and Figure 5.15 with the following properties set. Table 5.12. Property Settings for the Controls Used on the First Page of This How-To Object Property Setting OleDbDataAdapter ID odaProducts SelectCommand SELECT ProductID, ProductName FROM Products DataSet ID dsProducts DataGrid ID dgProducts DataSource dsProducts DataKeyField ProductID DataMember Products HyperLink ID hplReturnToMain NavigateURL wfrmMain.aspx 2. Right-click on the DataGrid control and choose Property Builder. Click on the Columns tab and set the properties as displayed in Figure 5.14. Be sure to note the name of the form you are calling in the URL Format String so that you can name it the same in step 4. 3. Add the code in Listing 5.30 to the Load event of the page. Listing 5.30 wfrmHowTo5_8a.aspx.vb: Filling and Binding the Products to the DataGrid Object Private Sub Page_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load 'Put user code to initialize the page here odaProducts.Fill(DsProducts) dgProducts.DataBind() End Sub 4. Create another Web Form. Then place the controls in Table 5.13 and Figure 5.16 with the following properties set. Table 5.13. Property Settings for the Controls Used on the Second Page of This How-To Object Property Setting Label Text Product Name Label Text Unit Price TextBox ID txtProductName TextBox ID txtUnitPrice 5. Add the code in Listing 5.31 to the Load event of the page. In the SQL select statement created in this listing, the Request.Item is used to grab the productID that was passed from the first form. The dtProdIndiv data table is filled, and the individual column information is loaded into the text boxes. Listing 5.31 wfrmHowTo5_8b.aspx.vb: Loading the Detail Information Based on the ProductID Private Sub Page_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load 'Put user code to initialize the page here Dim odaProdIndiv As OleDb.OleDbDataAdapter odaProdIndiv = New _ OleDb.OleDbDataAdapter(_ "Select * From Products Where ProductID = " & Request.Item("ID"), BuildCnnStr("(local)", "Northwind")) Dim dtProdIndiv As New DataTable() odaProdIndiv.Fill(dtProdIndiv) With dtProdIndiv.Rows(0) Me.txtProductName.Text = .Item("ProductName") Me.txtUnitPrice.Text = .Item("UnitPrice") End With End Sub Figure 5.16. You will use the request object in code on this page to retrieve detail data. Comments That's it! A good way to expand this example is to add the coding technique learned in the previous How-To for editing data. Using data with your Web Forms is not much harder than using Windows Forms. Just remember to stash some variables for round trips to the server and to bind your data. . 5.8 Hyperlink from a Row in the Data Grid to a Detail Page Often, I need to zero in and display data based on a record in the DataGrid control .NET-Chapter 5 solution. From the main page, click on the hyperlink with the caption How -To 5.8: Hyperlink From a Row in the Data Grid to a Detail Page.