word pdf 417

word pdf 417

word barcode font free, code 128 font for word, microsoft word code 39 barcode font, data matrix code word placement, ean 128 word 2007, word ean 13 barcode font, word pdf 417, microsoft word qr code, upc-a barcode font for word

Visual Studio 2005 doesn t support adding old web pages to a new web application using the Website Add Existing Item. If you take this step and try to run your web application, you ll receive an error informing you that the Visual Studio .NET 2003 version of the code-behind model is no longer supported. Instead, Visual Studio will recommend you use the Open Project feature to start the Conversion Wizard. However, it s not too difficult to get around this limitation. Simply edit your .aspx page by changing the Codebehind attribute to Src. In other words, this code: <%@ Page language="vb" Codebehind="MyPage.aspx.vb" AutoEventWireup="false" Inherits="MyApp.MyPage" %> becomes this: <%@ Page language="vb" Src="MyPage.aspx.vb" AutoEventWireup="false" Inherits="MyApp.MyPage" %> This change switches the page so it uses the named code file directly. In most situations, this tactic isn t recommended because it leaves many details of the old coding model intact (such as the way event handlers are wired up), and it won t catch other problems that could thwart conversion. However, it s a good last resort if you want to keep your web page relatively unchanged so that you can bring it back into the Visual Studio .NET 2003 environment later.

Once you ve attached the ObjectDataSource to a class, the next step is to point it to the methods it can use to select and update records. The ObjectDataSource defines SelectMethod, DeleteMethod, UpdateMethod, and InsertMethod properties that you use to link your data access class to various tasks. Each property takes the name of the method in the data access class. In this example, you simply need to enable querying, so you need to set the SelectMethod property: <asp:ObjectDataSource ID="sourceEmployees" runat="server" TypeName="DatabaseComponent.EmployeeDB" SelectMethod="GetEmployees" /> Remember, the GetEmployees() method returns an array of EmployeeDetails objects. These objects fit the criteria of the ObjectDataSource they provide all the appropriate record data through public properties. Once you ve set up the ObjectDataSource, you can bind your web-page controls in the same way you do with the SqlDataSource. You can even use the same drop-down lists in the Properties window, provided you click the Refresh Schema link in the ObjectDataSource smart tag first. When you click Refresh Schema, Visual Studio retrieves the property names and data types by reflecting on the EmployeeDetails class. Here s the complete page code, without the formatting details for the GridView: <asp:ObjectDataSource ID="sourceEmployees" runat="server" TypeName="DatabaseComponent.EmployeeDB" SelectMethod="GetEmployees"/> <asp:ListBox ID="ListBox1" runat="server" DataSourceID="sourceEmployees" DataTextField="EmployeeID"></asp:ListBox> <br /> <asp:GridView ID="GridView1" runat="server" DataSourceID="sourceEmployees"> </asp:GridView> Figure 9-11 shows the result.

Abandon()

To start designing a web page, double-click the web page in the Solution Explorer (start with Default.aspx if you haven t added any pages). A blank page will appear in the designer. To add controls, choose the control type from the Toolbox on the left. (The controls in the Toolbox are grouped in numerous categories based on their functions, but you ll find basic ingredients in the Standard tab.) Once you ve added a control, you can resize it and configure its properties in the

Figure 9-11. Binding to a data access class From the user s perspective, this example is equivalent to the SqlDataSource page shown in Figure 9-8. The only difference is that by default, the columns are shown in the order that the properties are declared in the class, whereas the SqlDataSource shows them in the order they re listed in the query. You can easily change the ordering of columns by customizing the GridView. The apparent similarities conceal some real behind-the-scenes differences. In this example, the web page doesn t require any hard-coded SQL details. Instead, all the work is handed off to the EmployeeDB class. When you run the page, the ListBox and GridView will request data from the ObjectDataSource, which will call the EmployeeDB.GetEmployees() method to retrieve the data (once for each control). This data is then bound and displayed in both controls, with no code required.

Clear()

Properties window. Every time you add a web control, Visual Studio automatically adds the corresponding tag to your .aspx web-page file. You can switch your view to look at the tags by clicking the Source button at the bottom of the web designer window. Click Design to revert to the graphical web form designer. Figure 2-5 shows two views of the same web page that contain a label and a button. One view is in HTML mode, and the other is in design mode.

Remember, the EmployeeDB class uses error-handling blocks to make sure connections are properly closed, but it doesn t catch exceptions. (Best design practices are to let the exception notify the web page, which can then decide how best to inform the user.) You can handle errors with the ObjectDataSource in the same way you handle them with the SqlDataSource first, handle the Selected, Inserted, Updated, or Deleted event; second, check for an exception; and third, mark it as handled. For more information, see the Handling Errors section earlier in the chapter.