Microsoft .NET–Specific Tags pot

Creating Web Applications with ASP.NET A Web application that uses ASP.NET typically consists of one or more ASP.NET pages or Web forms, code files, and configuration files. A Web form is held in an .aspx file, which is essentially an HTML file with some Microsoft .NET–specific tags. An .aspx file defines the layout and appearance of a page. Each .aspx file often has an associated code file containing the application logic for the components in the .aspx file, such as event handlers and utility methods. A tag, or directive, at the start of each .aspx file specifies the name and location of the corresponding code file. ASP.NET also supports application-level events, which are defined in Global.asax files. Each Web application can also have a configuration file called Web.config. This file, which is in XML format, contains information regarding security, cache management, page compilation, and so on. Building an ASP.NET Application In the following exercise, you will build a simple ASP.NET application that uses Server controls to gather input from the user about the details of the employees of a fictitious software company. The application will show you the structure of a typical Web application. NOTE You do not need to have IIS running on your computer in order to develop Web applications. Visual Studio 2005 includes its own Development Web server. When you build and run a Web application, by default Visual Studio 2005 will run the application using this server. However, you should still use IIS for hosting production Web applications after you have finished developing and testing them. Create the Web application 1. Start Microsoft Visual Studio 2005, if it is not already running. 2. On the File menu, point to New and then click Web Site. The New Web Site dialog box appears. 3. Click the ASP.NET Web Site template. Select File System in the Location drop- down list box, and type C:\Documents and Settings\YourName\My Documents\Microsoft Press\Visual CSharp Step by Step\Chapter 25\HonestJohn where YourName is your Windows login name. Set the Language to Visual C#, and then click OK. NOTE Setting the Location to FileSystem uses the Development Web server provided with Visual Studio 2005. You can use IIS by setting the Location to HTTP and specifying the URL of the Web Site you want to create rather than a file name. An application is created consisting of a Web Folder called App_Data, and a Web form called Default.aspx. The HTML code for the default page appears in the Source View window. 4. In the Solution Explorer select the Default.aspx file. In the Properties window, change the File Name property of Default.aspx to EmployeeForm.aspx. 5. Click the Design button at the bottom of the form to display the Design View of the form. The Design View window is currently empty. In the Design View window, you can drag controls onto the Web form from the Toolbox, and Visual Studio 2005 will generate the appropriate HTML for you. This is the HTML that you see when you view the form in the Source View window. You can also edit the HTML directly if you want. In the next exercise, you will define a style to be used by the form and add controls to the form to make it functional. Using a style enables you to ensure that all controls on the form share a common look and feel (such as color and font), as well as setting items such as a background image of the form. Lay out the Web form 1. Click the form in the Design View window. In the Properties window, change the Title property of the DOCUMENT object to Employee Information. The value you specify for the Title property appears in the title bar of the Web Browser when you run the Web application. 2. Select the Style property and click the ellipses button. The Style Builder dialog box opens. This dialog box allows you to create a style for the form. (A style specifies the default font, color, layout, and other attributes for the Web form and its controls.) 3. In the Font Name section, verify that the Family option is selected, and then click the ellipses button on the right side. In the Font Picker dialog box that opens, select Arial in the Installed Fonts list, and then click the >> button to add it to the Selected Fonts list. Click OK to return to the Style Builder dialog box. 4. In the Color drop-down list, select Blue. 5. In the left pane of the dialog box, click Background. The Background page is displayed. Select the Transparent check box. 6. Using Windows Explorer, copy the file \Microsoft Press\Visual CSharp Step By Step\Chapter 25\computer.bmp in your My Documents folder to the \Microsoft Press\Visual CSharp Step By Step\Chapter 25\HonestJohn folder. 7. Return to the Style Builder dialog box in the Visual Studio 2005 programming environment. In the Image text box, type computer.bmp. Click OK. The Web form will contain a background image of a computer. 8. Open the Toolbox and ensure that the Standard category is expanded. The Toolbox contains controls that you can drop onto ASP.NET forms. These controls are similar, in many cases, to the controls you have been using to build Windows forms. The difference is that these controls have been designed to operate in an HTML environment, and they are rendered using HTML at run time. 9. From the Toolbox, drag and drop four Label controls and three TextBox controls onto the Web form. Notice how the controls pick up the font and color specified by the Web form's style. NOTE The controls will be automatically positioned using a left-to-right flow layout in the Design View window. Do not worry about their location just yet as you will move them after setting their properties. NOTE As well as using a Label control, you can also type text directly onto a Web page. However, you cannot format this text so easily, set properties, or apply Themes to it. If you are building a Web site that has to support different languages (such as French or German), use Label controls as you can more easily localize the text they display by using Resource files. For more information, see “Resources in Applications” in the Microsoft Visual Studio 2005 Documentation. 10. Using the Properties window, set the properties of these controls to the values shown in the following table. Control Property Value Control Property Value Label1 Font Bold (expand the Font property) True Font Name Arial Black Font Size X-Large Text Honest John Software Developers Height 36px Width 630px Label2 Text First Name Label3 Text Last Name Label4 Text Employee Id TextBox1 Height 24px Width 230px (ID) firstName TextBox2 Height 24px Width 230px (ID) lastName TextBox3 Height 24px Width 100px (ID) employeeID 11. In the Design View window, select all four labels and all three text boxes (click Label1, and the click the remaining controls while holding down the Shift key). 12. In the Layout menu, point to Position and then click Absolute. This setting enables you to drag the controls to an absolute position on the form rather than Visual Studio 2005 laying them out automatically. 13. Move the labels and text boxes to the positions shown on the form in the following graphic: TIP You can align and space controls by using the commands on the Format menu. To align a set of controls, select them all and then, on the Format menu, click Align and select the appropriate alignment (Lefts, Centers, Rights, Tops, Middles, Bottoms). Similarly, you can space controls by selecting them and then by using the Horizontal Spacing or Vertical Spacing commands on the Format menu. 14. Click the Source button at the bottom of the form to display the HTML representation of the form and controls in the Source View window. The HTML should look like similar to the following code (the positions of the controls might vary slightly on your form): <%@ Page Language="C#" AutoEventWireup="true" CodeFile="EmployeeForm.aspx.cs" Inherits="_Default" %> <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.1//EN" "http://www.w3.org/TR/xhtml11/DTD/ xhtml11.dtd"> <html xmlns="http://www.w3.org/1999/xhtml" > <head runat="server"> <title>Employee Information</title> </head> <body style="background-image: url(computer.bmp); color: blue; font-family: Arial; background-color: transparent"> <form id="form1" runat="server"> <div> <asp:Label ID="Label1" runat="server" Text="Honest John Software Developers" style="z-index: 100; left: 96px; position: absolute; top: 24px" Font-Bold="True" Font- Names="Arial Black" Font-Size="X-Large" Height="36px" Width="630px"></asp:Label> <asp:Label ID="Label2" runat="server" Text="First Name" style="z-index: 101; left: 62px; position: absolute; top: 104px"></asp:Label> <asp:Label ID="Label3" runat="server" Text="Last Name" style="z-index: 102; left: 414px; position: absolute; top: 104px"></asp:Label> <asp:Label ID="Label4" runat="server" Text="Employee Id" style="z-index: 103; left: 62px; position: absolute; top: 167px"></asp:Label>&nbsp;&nbsp; <asp:TextBox ID="firstName" runat="server" style="z-index: 104; left: 156px; position: absolute; top: 101px" Height="24px" Width="230px"></asp:TextBox> <asp:TextBox ID="lastName" runat="server" style="z-index: 107; left: 507px;  . A Web form is held in an .aspx file, which is essentially an HTML file with some Microsoft .NET–specific tags. An .aspx file defines the layout and appearance of a page. Each .aspx file often. 6. Using Windows Explorer, copy the file Microsoft PressVisual CSharp Step By StepChapter 25computer.bmp in your My Documents folder to the Microsoft PressVisual CSharp Step By StepChapter. in the Location drop- down list box, and type C:Documents and SettingsYourNameMy Documents Microsoft PressVisual CSharp Step by StepChapter 25HonestJohn where YourName is your Windows