Does C# have an equivalent to JavaScript's encodeURIComponent()?

c# javascript .net windows encoding
travis picture travis · Sep 17, 2008 · Viewed 104.2k times · Source

In JavaScript:

encodeURIComponent("©√") == "%C2%A9%E2%88%9A"

Is there an equivalent for C# applications? For escaping HTML characters I used:

txtOut.Text = Regex.Replace(txtIn.Text, @"[\u0080-\uFFFF]",
    m => @"&#" + ((int)m.Value[0]).ToString() + ";");

But I'm not sure how to convert the match to the correct hexadecimal format that JS uses. For example this code:

txtOut.Text = Regex.Replace(txtIn.Text, @"[\u0080-\uFFFF]",
    m => @"%" + String.Format("{0:x}", ((int)m.Value[0])));

Returns "%a9%221a" for "©√" instead of "%C2%A9%E2%88%9A". It looks like I need to split the string up into bytes or something.

Edit: This is for a windows app, the only items available in System.Web are: AspNetHostingPermission, AspNetHostingPermissionAttribute, and AspNetHostingPermissionLevel.

Answer

Steve picture Steve · Dec 29, 2010

Uri.EscapeDataString or HttpUtility.UrlEncode is the correct way to escape a string meant to be part of a URL.

Take for example the string "Stack Overflow":

  • HttpUtility.UrlEncode("Stack Overflow") --> "Stack+Overflow"

  • Uri.EscapeUriString("Stack Overflow") --> "Stack%20Overflow"

  • Uri.EscapeDataString("Stack + Overflow") --> Also encodes "+" to "%2b" ---->Stack%20%2B%20%20Overflow

Only the last is correct when used as an actual part of the URL (as opposed to the value of one of the query string parameters)

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