Uri.HexEscape(Char) Method in C#

The Uri.HexEscape() method in C# converts a specified character into its hexadecimal equivalent representation using percent-encoding. This method is particularly useful for URL encoding where certain characters need to be represented in hexadecimal format for safe transmission in URIs.

Syntax

Following is the syntax −

public static string HexEscape(char ch);

Parameters

ch − The character to convert to hexadecimal representation.

Return Value

Returns a string containing the hexadecimal representation of the character in the format %XX, where XX is the two-digit hexadecimal value.

Using HexEscape for Lowercase Characters

Example

using System;
public class Demo {
   public static void Main() {
      char ch = 'k';
      string res = Uri.HexEscape(ch);
      Console.WriteLine("Character: " + ch);
      Console.WriteLine("Hexadecimal Equivalent = " + res);
      
      // Show ASCII value for reference
      Console.WriteLine("ASCII Value: " + (int)ch);
   }
}

The output of the above code is −

Character: k
Hexadecimal Equivalent = %6B
ASCII Value: 107

Using HexEscape for Uppercase Characters

Example

using System;
public class Demo {
   public static void Main() {
      char ch = 'P';
      string res = Uri.HexEscape(ch);
      Console.WriteLine("Character: " + ch);
      Console.WriteLine("Hexadecimal Equivalent = " + res);
      
      // Show ASCII value for reference
      Console.WriteLine("ASCII Value: " + (int)ch);
   }
}

The output of the above code is −

Character: P
Hexadecimal Equivalent = %50
ASCII Value: 80

Using HexEscape for Special Characters

Example

using System;
public class Demo {
   public static void Main() {
      char[] specialChars = {' ', '@', '&', '?', '#'};
      
      Console.WriteLine("Special Character Hex Encoding:");
      foreach(char ch in specialChars) {
         string hexValue = Uri.HexEscape(ch);
         Console.WriteLine($"'{ch}' ? {hexValue} (ASCII: {(int)ch})");
      }
   }
}

The output of the above code is −

Special Character Hex Encoding:
' ' ? %20 (ASCII: 32)
'@' ? %40 (ASCII: 64)
'&' ? %26 (ASCII: 38)
'?' ? %3F (ASCII: 63)
'#' ? %23 (ASCII: 35)

Common Use Cases

• URL Encoding − Converting special characters for safe URL transmission.

• Query String Parameters − Encoding values that contain reserved characters.

• File Path Encoding − Converting characters that are not allowed in file names or paths.

Conclusion

The Uri.HexEscape() method provides a simple way to convert individual characters to their percent-encoded hexadecimal representation. This is essential for URL encoding and ensuring proper character handling in web applications and URI processing.