How do you handle URL encoding and decoding when using Query Strings in ASP.NET?
In ASP.NET, you can handle URL encoding and decoding when working with query strings using built-in methods and classes provided by the framework. The HttpUtility class in the 'System.Web' namespace offers encoding and decoding methods specifically designed for working with URLs.
To encode a string to be used as a query string parameter value, you can use the 'HttpUtility.UrlEncode(') method. This method takes a string input and returns the URL-encoded representation of the input string.
Here's an example of encoding a parameter value before including it in a query string:
string originalValue = "ASP.NET web development";
string encodedValue = HttpUtility.UrlEncode(originalValue);
// encodedValue will be "ASP.NET%20web%20development"
In this example, the UrlEncode() method is used to encode the 'originalValue' string, which contains spaces. The resulting 'encodedValue' is the URL-encoded version of the input string, with spaces represented as "%20".
To decode a URL-encoded value retrieved from a query string, you can use the 'HttpUtility.UrlDecode()' method. This method takes a URL-encoded string input and returns the decoded version of the input string.
Here's an example of decoding a query string parameter value:
string encodedValue = "ASP.NET%20web%20development";
string decodedValue = HttpUtility.UrlDecode(encodedValue);
// decodedValue will be "ASP.NET web development"
In this example, the 'UrlDecode()' method is used to decode the 'encodedValue' string, which contains "%20" representing spaces. The resulting 'decodedValue' is the decoded version of the input string, where "%20" is converted back to spaces.
By using these encoding and decoding methods, you can ensure that query string parameter values are properly encoded before including them in URLs and that they are correctly decoded when retrieving them on the target page. This helps to avoid issues with special characters and ensures compatibility and integrity when working with query strings in ASP.NET.