Reading the userAgent with C#

Question

I have the following code which reads the userAgent and does some logic based on the values matched using indexOf:

String userAgent;
userAgent = Request.UserAgent;
// If it's not IE
if (userAgent.IndexOf("MSIE") < 0)
{
    return RedirectToAction("Index", "Home", new { area = "Dashboard" });
}
// If it's IE BUT ChromeFrame
else if(userAgent.IndexOf("ChromeFrame") > -1)
{
    return RedirectToAction("Index", "Home", new { area = "Dashboard" });
}
// It's just IE
else
{
    return View("ChromeFrame");
}

If it's IE then it should return the view or if its IE but contains ChromeFrame then it should redirect and it's another browser then it should redirect as well.

I think the problem is with the > 0 part of the code. What is the correct way of comparing info? Thanks.

you shouldn't change the code in a way that the answers you already got don't apply anymore... — Yahia, Jan 27 '12 at 10:29

score 8 · Answer 1 · edited May 23 '17 at 11:50

8

Just use the contains method, which will make your code less cryptic and less error-prone.

if (userAgent.Contains("MSIE"))
{
    return RedirectToAction("Index", "Home", new { area = "Dashboard" });
}

edited May 23 '17 at 11:50

Community

1
1

answered Jan 27 '12 at 10:29

Nikita Ignatov

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score 1 · Answer 2 · answered Jan 27 '12 at 10:22

1

You should be using > -1 as otherwise it will not work if the substring is at the beginning of the string.

answered Jan 27 '12 at 10:22

annonymously

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score 1 · Answer 3 · answered Jan 27 '12 at 10:23

1

IndexOf returns -1 if the string is not found... see MSDN for reference.

answered Jan 27 '12 at 10:23

Yahia

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Reading the userAgent with C#

3 Answers3

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