By default, Visual Studio creates an event handler by including a Handles clause on the Sub procedure. To set it differently you must create a list item object and then add that item to the collection.This clause names the control and event that the procedure handles. Some events are not posted back to the server immediately, these are called non-postback events. The nonpostback events could be made to post back immediately by setting their Auto Post Back property to true. The List Item Collection Editor is used to add item to a drop-down list or list box. To display the collection editor, select edit item from the smart tag menu, or select the control and then click the ellipsis button from the Item property in the properties window.
NET application codes can be written in any of the following languages: ASP. Basic syntax of text control: Specifies the type of text box.
The server processes the output of the client actions and triggers the reactions. The session state is the collective information obtained from various pages the user visited and worked with, i.e., the overall session state. The page itself is instantiated as a control object. In this tutorial we will explore the Server object, the Request object, and the Response object. The following table provides some noteworthy properties of the Request object: The Response object represents the server's response to the client request. Using these tools, the users can enter data, make selections and indicate their preferences. The code behind the file should look like this: using System; using System. If you want check box or radio button to be selected when the form is initially displayed, set its Checked attribute to true.
NET runtime codes, and incorporates the state of the server side components in hidden fields. The Web Control class itself and some other server controls that are not visually rendered are derived from the System. List boxes and drop-down lists contain one or more list items.
This way, the server becomes aware of the overall application state and operates in a two-tiered connected way. NET component model provides various building blocks of ASP. Basically it is an object model, which describes: All ASP. These lists can be loaded either by code or by the List Item Collection editor.
The basic syntax of Assembly directive is: The Import directive imports a namespace into a web page, user control page of application.
If the Import directive is specified in the file, then it is applied to the entire application.
It consists of a large number of controls such as text boxes, buttons, and labels for assembling, configuring, and manipulating code to create HTML pages. NET web forms extend the event-driven model of interaction to the web applications. The Http Server Utility class provides numerous properties and methods to perform various jobs. It represents the values and properties of the HTTP request that makes the page loading into the browser. NET, the response object does not play any vital role in sending HTML text to the client, because the server-side controls have nested, object oriented methods for rendering themselves. The following table shows the inherited properties, common to all server controls: Let us look at a particular server control - a tree view control. Edit each of the nodes using the Tree view node editor as shown: Once you have created the nodes, it looks like the following in design view: The Auto Format... A check box displays a single option that the user can either check or uncheck and radio buttons present a group of options from which the user can select just one option.
NET applications are compiled codes, written using the extensible and reusable components or objects present in . These codes can use the entire hierarchy of classes in . NET is used to produce interactive, data-driven web applications over the internet. Single Line creates a standard text box, Multi LIne creates a text box that accepts more than one line of text and the Password causes the characters that are entered to be masked. The mostly used attribute for a label control is 'Text', which implies the text displayed on the label.
To clear the concept, let us take an example of a shopping cart. Items are selected from a page, say the items page, and the total collected items and price are shown on a different page, say the cart page. Controls are also used for structural jobs, like validation, data access, security, creating master pages, and data manipulation. NET uses five types of web controls, which are: ASP. If the Checked attribute is set to true for multiple radio buttons in a group, then only the last one is considered as true.
Only HTTP cannot keep track of all the information coming from various pages. NET session state and server side infrastructure keeps track of the information collected globally over a session. NET runtime carries the page state to and from the server across page requests while generating ASP. NET server controls with a visual aspect are derived from the Web Control class and inherit all the properties, events, and methods of this class. Basic syntax of check box: These control let a user choose from one or more items from the list.
In this chapter, we will discuss the basic controls available in ASP. A text box control can accept one or more lines of text depending upon the settings of the Text Mode attribute.