C# HTML Encode

HTML encoding is the process of converting characters into their equivalent HTML entities. This is used to prevent HTML injection attacks by encoding special characters in user input as HTML entities. In this tutorial, we'll discuss how to use the System.Web.HttpUtility.HtmlEncode method in C# to encode HTML entities.

Syntax

The syntax for using the HtmlEncode method in C# is as follows:

string encodedString = System.Web.HttpUtility.HtmlEncode(string value);

The HtmlEncode method takes a string input and returns a string output, which is the encoded string that replaces special characters with their equivalent HTML entities.

Example

Let's say we have a string that contains special characters and we want to encode it before rendering it on a webpage. Here's how we can do it:

string inputString = "This is <b>bold text</b>.";
string encodedString = System.Web.HttpUtility.HtmlEncode(inputString);
Console.WriteLine(encodedString); // Output: This is &lt;b&gt;bold text&lt;/b&gt;.

Output

When we run the example code above, the output will be:

This is <b>bold text</b>.

This is because the input string was encoded and the special characters were replaced with their equivalent HTML entities.

Explanation

In the example above, we used the HtmlEncode method to encode a string that contains special characters. We passed the input string to the method, and it returned a new string that has the special characters replaced with their equivalent HTML entities.

Use

HTML encoding is important when rendering user input on a webpage to prevent HTML injection attacks. By encoding special characters in user input as HTML entities, you can prevent attackers from injecting malicious code into your webpage.

Important Points

• The HtmlEncode method replaces the following characters with their equivalent HTML entities: <, >, &, ", and '.
• If you're using .NET Core, you can use the Microsoft.AspNetCore.WebUtilities.HtmlEncoder class instead of System.Web.HttpUtility.

Summary

In this tutorial, we discussed how to use the System.Web.HttpUtility.HtmlEncode method in C# to encode HTML entities. We covered the syntax, example, output, explanation, use, and important points of HTML encoding in C#. With this knowledge, you can now use the HtmlEncode method in your C# code to encode special characters in user input when rendering it on a webpage.