Adding the composite control to a page in Visual Studio .NET

Creating Code 128B in Visual Studio .NET Adding the composite control to a page
Adding the composite control to a page
USS Code 128 Recognizer In VS .NET
Using Barcode Control SDK for VS .NET Control to generate, create, read, scan barcode image in VS .NET applications.
After you have compiled the composite control into a DLL, you can include it in a Web application. The steps to include the control into a Web application are given as follows: 1. Create a new ASP Web application or open an existing project. 2. Add a reference to the custom control that you created in the previous step. To add a reference, in the Add Reference dialog box, select the Projects tab and browse to the DLL file of your custom control. 3. In the HTML source file, specify the @ Register directive to register the control. For example, if the name of the control namespace is CalcControl and the name of the class library project is CustomControls, you can register the control by specifying the following statement: 4. <%@ Register TagPrefix="Custom" Namespace="CalcControl" Assembly =
Code 128 Drawer In Visual Studio .NET
Using Barcode generation for .NET framework Control to generate, create Code 128B image in Visual Studio .NET applications.
"CustomControls" %> 5. Include the control on the page by using the tag name with which the control was registered. For example, in the preceding case, the tag name is Custom. Therefore, to include the control in the <BODY> region of the form, write the following code: 6. 7. 8. <form id="Form1" method="post" runat="server"> <Custom:CalcClass id="CalcClass" Text="Select options and click Submit" runat="server" />
Code128 Recognizer In .NET Framework
Using Barcode decoder for .NET framework Control to read, scan read, scan image in .NET framework applications.
</form> After you have included the control, it appears as displayed in Figure 5-2.
Generate Bar Code In .NET
Using Barcode drawer for Visual Studio .NET Control to generate, create barcode image in .NET framework applications.
Figure 5-2: Composite control on a form You can check whether the control is functioning correctly by selecting a date less than 1975 and specifying the work experience of more than five years. The output after you specify the aforesaid values is given in Figure 5-3.
Barcode Scanner In VS .NET
Using Barcode recognizer for VS .NET Control to read, scan read, scan image in Visual Studio .NET applications.
Figure 5-3: Data validation by the composite control
Code128 Encoder In C#
Using Barcode generation for .NET framework Control to generate, create Code 128C image in .NET applications.
Adding Properties and Methods
ANSI/AIM Code 128 Encoder In .NET Framework
Using Barcode encoder for ASP.NET Control to generate, create ANSI/AIM Code 128 image in ASP.NET applications.
After creating a custom control, you can add properties and methods to it and obtain the functionality you want in your control. Properties are specifications that qualify the appearance and behavior of controls. In the case of standard controls, you can specify the property values either at design time or run time. At design time, the properties can be specified using the Toolbox. At run time, the implemented code sets the properties. If a property has a set accessor, the syntax to set a property would be as follows: control.property = value In this syntax: control signifies the name of the control. property signifies the property that you want to set for the control. value is the value that you specify for the property. Methods are functions or procedures that provide a specific functionality to a control. Each Web Forms control has a set of methods associated with it. You can call a method of a control by using the following syntax: control.method In this syntax, control represents the name of the control and method represents the method associated with the control. You can add properties and methods to custom controls also. To add a property to a user control, you need to write the code in the ASCX file of the control. Consider the example wherein you created a user control earlier in the chapter. To add properties, ProductID and ProductName, you need to add the following code in the class that implements the control: <script language="C#" runat="server"> public String ProductID { get { return Product_ID.Text; } set {
Paint Code 128 Code Set B In Visual Basic .NET
Using Barcode creation for VS .NET Control to generate, create Code 128C image in .NET framework applications.
Product_ID.Text = value; } } public String ProductName { get { return Product_Name.Text; } set { Product_Name.Text = value; } } </script> In this code, the get and set properties have been used. The get property is used to retrieve the value associated with the property. The set property is used to assign a value to a property.
EAN-13 Generator In .NET Framework
Using Barcode generation for VS .NET Control to generate, create UPC - 13 image in VS .NET applications.
Handling and Exposing Events
Draw Barcode In Visual Studio .NET
Using Barcode generator for VS .NET Control to generate, create bar code image in .NET framework applications.
Each control has events associated with it. Events are generated as a result of user interaction or can be raised from other procedures. In Web Forms controls, the events are raised and handled on the server. An action is requested from the client side to the server with the help of a Web request. Then, the control raises an event on the server as a response to the client action. After the page or controls handle the event, the response is sent back to the client. This results in user experience similar to a desktop application. Note Only the postback event can be posted to the server. User interface events that occur on the client side, such as mouse clicks or key presses, can only be communicated to the server by using postback events. You can associate custom events with your controls. Handling user control events is more or less the same as handling events in any other Web Forms control. You need to decide whether to use the event handler in the containing Web Forms page or the user control. Writing event handlers in either of the cases is similar. However, you need to take some precautions if you decide to include the event handler in the user control. For example, if you have included the properties for the control in the existing Web Forms page, the properties will not be accessible from the user control unless you add functionality within the user control. Let us create a button and add an event handler to it. Consider the user control that you created earlier in the chapter. You can add an event in such a way that whenever you write a value in the Product_ID text box and click a button labeled "Buy Now!," the name of the product will automatically appear in the Product_Name text box. To add the button to the control, add the following code: <asp:Button id=Buy runat="server" Text="Buy Now!" OnClick="Buy_Click"></asp:Button> The ID of the Button control is Buy. Th e button can achieve the desired functionality by the following code:
GTIN - 12 Creator In .NET
Using Barcode generation for .NET Control to generate, create UPC Symbol image in VS .NET applications.
<script language="Vb" runat="server" ID=Script1> Sub Buy_Click (Src As Object, E As EventArgs) If MyProduct.ProductID="P001" Then MyProduct.ProductName="Toys" End If End Sub </script> This code is executed when a user clicks the button "Buy Now!" After a user clicks this button, the value of the TextBox labeled Product_Name is set to "Toys" if a user enters the product code as "P001."
Printing UPC E In .NET
Using Barcode generator for .NET framework Control to generate, create UPC-E Supplement 5 image in VS .NET applications.
Summary
Code 39 Extended Scanner In VS .NET
Using Barcode scanner for .NET framework Control to read, scan read, scan image in .NET framework applications.
In this chapter, you learned the basic structure of Web Forms controls and looked at the classes used for them. You explored the custom controls in detail. First, you learned how to create and use user controls. Then, you learned how to create and use composite controls. In this process, you learned how to use events, methods, and properties with custom controls.
Printing Barcode In Java
Using Barcode generation for Java Control to generate, create bar code image in Java applications.
6:
Code39 Drawer In Java
Using Barcode encoder for Java Control to generate, create Code-39 image in Java applications.
Generate Barcode In Visual Basic .NET
Using Barcode printer for .NET Control to generate, create bar code image in .NET applications.
Making Code 39 Full ASCII In VS .NET
Using Barcode generator for ASP.NET Control to generate, create Code 39 Full ASCII image in ASP.NET applications.
Barcode Generator In .NET Framework
Using Barcode creator for ASP.NET Control to generate, create bar code image in ASP.NET applications.