Managing states in an ASP.NET application is crucial for providing a stress-free user experience. States are the information and settings that are maintained by the server- or client-side scripting languages. This is especially true during the practical experiment of an application.
It involves tools like application state, session state, and view state. Application state stores values accessible from all pages; session state preserves user-specific data throughout a session. While the view state maintains the state of an object across page requests at all times,.
In an ASP.NET application, state management is a very crucial instrument for preserving user data and control information. These techniques ensure that user information is retained and can be accessed as needed. In this article, we will answer your query of how do you manage states in ASP.NET application?
Simple Ways to Manage States in ASP.NET Application
By effectively managing both client-side and server-side states in your ASP.NET application. You can provide a more seamless and responsive user experience. And that’s while minimizing network traffic and improving performance.
1. ViewState
ViewState is a server-side mechanism used to maintain the state of user interface elements between postbacks. It is stored as hidden fields in the HTML page sent to the client. And the server restores the values during any other request.
It is used to persist the state of an object across different requests for the same page. This is used for preserving the value of a control between round trips. Note that to use ViewState, set the EnableViewState property of the Page directive to true.
This hidden field is automatically generated by ASP.NET for each page. This allows you to maintain the state of server-side objects between requests. You can do this without requiring round-trip trips to the server for each update.
This is an example:
“`csharp
<%@ Page Language=”C#” AutoEventWireup=”true” CodeBehind=”Default.aspx.cs” Inherits=”WebApplication1.Default” EnableViewState=”true” %>
“`
2. Session State
This is another way to manage states in ASP.NET application. Session state is used to maintain data across multiple requests from a single user. But it is stored on the server and can easily be accessed from any page in the application.
This enables you to store and retrieve values for a user. Each time you navigate the web pages in a particular session. And this is useful for storing user-specific information. To use session state, set the EnableSessionState property of the page directive to true.
Furthermore, it is a temporary storage mechanism that is available for the duration of a user’s session (i.e., until they close their browser window). This allows you to maintain state for objects that need to be shared across multiple pages or requests within a single session.
This is an example:
“`csharp
<%@ Page Language=”C#” AutoEventWireup=”true” CodeBehind=”Default.aspx.cs” Inherits=”WebApplication1.Default” EnableSessionState=”true” %>
“`
3. Application State
Application state is used to maintain data across multiple users and sessions. It is stored on the server and can be accessed from any page in the application.
To use the application state, you have to set the EnableAppSession property of the page directive to true. Also, you have to create a static variable to store the data at the application level.
Furthermore, it allows you to save values that are accessible from all pages in the web application. This is a useful tool for storing global information.
This is an example of a command:
“`csharp
<%@ Application Language=”C#” %>
public static int TotalUsers = 0;
<%@ Page Language=”C#” AutoEventWireup=”true” CodeBehind=”Default.aspx.cs” Inherits=”WebApplication1.Default” EnableAppSession=”true” %>
“`
4. Query String
Query string is used to pass data between pages using URL parameters. It is accessible through the Request object’s QueryString property in C# code. Just behind files or as a collection in JavaScript files using the location object’s search property.
To pass data using a query string, hang a key-value pair to the URL after a question mark (?). It is a part of a URL that assigns values and includes fields added to a base URL. This is done by a web browser or other client by choosing the appearance of a page or jumping to positions in multimedia content.
The query string begins after the question mark (?) and can include one or more parameters. Each item is represented by a unique key-value pair or a set of two linked features. An equals sign (=) separates each key and value, and an ampersand (&) separates multiple parameters.
However, query strings do have certain limitations, such as length constraints and a lack of security. It is good that you properly validate and check query string parameters on the server side. And also use encryption or authentication patterns, depending on the sensitivity of the information.
Examples
“`csharp
// C# code behind file (Default.aspx.cs)
string username = Request[“username”]; // Retrieve username from query string parameter “username”
Response.Redirect(“ResultPage.aspx?username=” + username); // Redirect to ResultPage with username as query string parameter
“`
2. JavaScript file (DefaultPageScripts.js)
“`javascript
// JavaScript file (DefaultPageScripts.js) – Access query string parameter “username” using location object’s search property in JavaScript files
var username = location.search.split(“username=”)[1].split(“&”)[0]; // Split query string parameter “username=value…” into an array and extract “value” part for “username” parameter only
“`
5. Cookies
Still confused? how do you manage states in ASP.NET application? You can also use cookies. They are used to store small pieces of data on the client’s machine for future reference. It is done by web applications or websites you visit again later in your browser session. Also in future sessions based on your preferences or login details.
To use cookies, set the Response object’s Cookies collection property in C# code behind files. And/or document object’s cookie property in JavaScript files. You can use the location object’s path property to specify the scope of cookie storage (path=”/”) for all pages. You can also use specific pages (path=”/HomePage”) based on the requirement.
To set cookies, create a new HttpCookie object with key-value pairs. And add it to the response object’s cookie collection property or the document object’s cookie property, respectively.
To retrieve cookies, access the response object’s cookie collection property or the document object’s cookie property, respectively.
To delete cookies, remove them from the response object’s cookie collection property or the document object’s cookie property.
Examples are:
1. C# code behind file (Default.aspx.cs) – Set and retrieve cookies using Response object’s Cookies collection property in C# code behind files
2. JavaScript file (DefaultPageScripts.js) – Set and retrieve cookies using document object’s cookie property in JavaScript files
3. C# code behind file (LoginPageCodeBehindFile) – Delete cookies using Response object’s Cookies collection property in C# code behind files
4. JavaScript file (LogoutPageScripts) – Delete cookies using document object’s cookie property in JavaScript files “`csharp // C# code behind file.
Types of State Management
State management refers to the process of maintaining and storing information. Information about the state of user interface controls. Such as radio buttons, action buttons, and input fields.
ASP.NET applications are originally stateless by default. And that means that the server creates a new instance of the web page every time a request is made.
This always results in the loss of user-entered data during roundtrips from the browser to the server. To overcome this limitation, ASP.NET provides various state management techniques, which include:
1. Server-Side State Management
Server-side state management refers to the state of an object or component that is maintained on the server side. This is on the web server using server-side technologies like ASP.NET.
Some examples of server-side state include session variables, application variables, and database connections. Remember that the application state stores global information. Session state preserves user-specific data throughout a session. While view state maintains the state of an object across page requests.
2. Client-Side State Management
Client-side state management is the state of an object or component that is shown on the client-side. Which means it is stored in the user’s browser using technologies like HTML5, JavaScript, and CSS.
Some examples of client-side state may include the contents of input fields. Also the position of scrollbars and the selected options in drop-down lists.
This client-side state management includes control states, hidden fields, and cookies. The control state cannot be modified, accessed directly, or disabled. Hidden fields and cookies are used to store data on the client’s browser.
Techniques for Managing Client-side State
1. HTML5 Local Storage
This allows you to store data locally in the user’s browser using JavaScript. And this persists even after the user closes and reopens the browser window.
2. Cookies
These are small text files that are stored on the user’s computer and sent back to the server with each request. This will allow you to maintain state across multiple requests from the same user.
Conclusion
Conclusively, ASP.NET also provides various built-in mechanisms for managing server-side state. States like session variables, application variables, and cache objects. These can be accessed using C# code in your application’s code-behind files.
State management is a crucial aspect of ASP.NET development. It ensures that the application can maintain and preserve the necessary information across multiple requests and sessions.