使用.Contains检查字符串是否包含字符时出错

Question

I am trying to find out if a string contains a character. I tried the following where ViewBag.Options is a string:

@ViewBag.Options.Contains('q')

but it gives me an error saying:

The best overloaded method match for 'string.Contains(string)' has some invalid arguments.

Answer 1

And it's write: string.Contains doesn't have an overload taking just a single character.

Options:

• Use @ViewBag.Options.Contains("q")
• Use @ViewBag.Options.IndexOf('q') != -1
• Use some more complicated LINQy approach (eg Any ) - feasible, but there's no need here. (I'm a fan of LINQ where appropriate but I don't think that's the right approach here; I wouldn't start introducing lambda expressions into my code just for the sake of it)
• Use some more complicated regular expression approach - again, there's no point.

Answer 2

Use any of them

• @ViewBag.Options.Contains("q");
• @ViewBag.Options.Any(x => x == 'q');

If you insist

• @ViewBag.Options.Contains('q'.ToString());

The error is self explanatory. Paramerters of .Contains takes a string and no overload of this method takes a character.

Answer 3

Using single quotes in c# indicates a character.

Try with double quotes:

@ViewBag.Options.Contains("q");

Answer 4

用这个：

@ViewBag.Options.Contains("q")