<\/p>\n\n\n\n
Here\u2019s a complete, copyright-free guide<\/strong> to Query Strings in C# \/ ASP.NET<\/strong>, including definition, examples, use cases, limitations, performance, and security<\/strong>. You can freely copy-paste this on your blog or Facebook page.<\/p>\n\n\n\n A query string<\/strong> is a part of the URL that carries data from one web page to another. It starts after a In ASP.NET, query strings are commonly used to pass small amounts of data between pages.<\/p>\n\n\n\n Always check for null:<\/p>\n\n\n\n Would you like a code sample project<\/strong>, visual diagram<\/strong>, or a PDF cheat sheet<\/strong> on this topic? Let me know!<\/p>\n","protected":false},"excerpt":{"rendered":" Here\u2019s a complete, copyright-free guide to Query Strings in C# \/ ASP.NET, including definition, examples, use cases, limitations, performance, and security. You can freely copy-paste this on your blog or Facebook page. \ud83d\udd17 Query String in C# ASP.NET \u2013 Complete Guide \ud83d\udcd8 Definition A query string is a part of the URL that carries data … <\/p>\n
\n\n\n\n\ud83d\udd17 Query String in C# ASP.NET \u2013 Complete Guide<\/h1>\n\n\n\n
\ud83d\udcd8 Definition<\/h2>\n\n\n\n
?<\/code><\/strong> and consists of key-value pairs, separated by &<\/code><\/strong>.<\/p>\n\n\n\n
\n\n\n\n\ud83e\uddfe Example of a Query String<\/h2>\n\n\n\n
https://example.com\/profile.aspx?userId=123&lang=en\n<\/code><\/pre>\n\n\n\n\n
?userId=123&lang=en<\/code> is the query string<\/strong>.<\/li>\n\n\n\nuserId<\/code> and lang<\/code> are keys<\/strong>, and 123<\/code>, en<\/code> are values<\/strong>.<\/li>\n<\/ul>\n\n\n\n
\n\n\n\n\ud83e\uddea How to Use Query Strings in ASP.NET<\/h2>\n\n\n\n
\ud83d\udd39 Send a Query String (Redirect with Data)<\/h3>\n\n\n\n
Response.Redirect(\"Profile.aspx?userId=123&lang=en\");\n<\/code><\/pre>\n\n\n\n\ud83d\udd39 Read a Query String<\/h3>\n\n\n\n
string userId = Request.QueryString[\"userId\"];\nstring lang = Request.QueryString[\"lang\"];\n<\/code><\/pre>\n\n\n\nif (Request.QueryString[\"userId\"] != null)\n{\n int userId = int.Parse(Request.QueryString[\"userId\"]);\n}\n<\/code><\/pre>\n\n\n\n
\n\n\n\n\u2705 Common Use Cases<\/h2>\n\n\n\n
Use Case<\/th> Example<\/th><\/tr><\/thead> Navigation between pages<\/td> Pass user ID, category ID, or search terms<\/td><\/tr> Bookmarkable URLs<\/td> Save filter\/search settings in URL<\/td><\/tr> Third-party API or link sharing<\/td> Share public resources with identifiers in the URL<\/td><\/tr> Tracking<\/td> Add campaign IDs, referral sources in URLs<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n
\n\n\n\n\u2699\ufe0f Limitations of Query Strings<\/h2>\n\n\n\n
Limitation<\/th> Description<\/th><\/tr><\/thead> \u274c Length limit<\/strong><\/td> Browsers limit URL length (commonly 2,000+ characters)<\/td><\/tr> \u274c Visible to user<\/strong><\/td> Anyone can see the data in the URL bar<\/td><\/tr> \u274c Not secure<\/strong><\/td> Never use query strings to send passwords or personal info<\/td><\/tr> \u274c Easy to modify<\/strong><\/td> Users can change values manually, potentially breaking logic<\/td><\/tr> \u274c Not suitable for large data<\/strong><\/td> Should be used for small<\/strong> pieces of information only<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n
\n\n\n\n\ud83d\ude80 Performance Impact<\/h2>\n\n\n\n
\n
\n\n\n\n\ud83d\udd10 Security Considerations<\/h2>\n\n\n\n
Concern<\/th> Recommendation<\/th><\/tr><\/thead> \ud83d\udd13 Data is exposed<\/td> Never pass sensitive info like passwords, tokens, or IDs directly<\/td><\/tr> \ud83e\uddea Input tampering<\/td> Always validate and sanitize<\/strong> query string values<\/td><\/tr> \ud83e\udda0 XSS attack risks<\/td> Use URL encoding<\/strong> and avoid rendering user input directly<\/td><\/tr> \ud83d\udd12 Use HTTPS<\/td> Prevents interception of query string in transit<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n \u2705 Example: Safe Value Handling<\/h3>\n\n\n\n
string name = Server.HtmlEncode(Request.QueryString[\"name\"]);\n<\/code><\/pre>\n\n\n\n
\n\n\n\n\ud83d\udccc Summary Table<\/h2>\n\n\n\n
Feature<\/th> Description<\/th><\/tr><\/thead> What is it?<\/td> Part of URL carrying data in key=value format<\/td><\/tr> Syntax<\/td> ?key1=value1&key2=value2<\/code><\/td><\/tr>Stored Where?<\/td> In browser URL (client side)<\/td><\/tr> Size Limit<\/td> Around 2000 characters (browser-dependent)<\/td><\/tr> Lifetime<\/td> Until user navigates or refreshes<\/td><\/tr> Secure?<\/td> \u274c No, unless encrypted or protected with HTTPS<\/td><\/tr> Use Cases<\/td> Search filters, public IDs, navigation, analytics<\/td><\/tr> Not Good For<\/td> Sensitive, large, or private data<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n
\n\n\n\n\ud83e\udde0 Pro Tips<\/h2>\n\n\n\n
\n
HttpUtility.UrlEncode()<\/code> if needed).<\/li>\n\n\n\n
\n\n\n\n