Need Regular Expression for path and file extension matching

Question

I need a regular expression for C# to return a match for allowed paths and file names.

The following should match:

• a (at least one character)
• xxx/bbb.aspx (path allowed and only .aspx extension is allowed)
• bbb.aspx?aaa=1 (querystring is allowed)

It should not match for:

• aaa.
• aaa.gif (only .aspx extension allowed)
• aaa.anythingelse

Answer 1

尝试这个：

[\w/]+(\.aspx(\?.+)?)?

Answer 2

.NET has built-in features for working with file paths, including finding file extensions. So I would strongly suggest using them instead of a regex. Here is a possible solution using System.IO.Path.GetExtension() . This is untested but it should work.

private static bool IsValid(string strFilePath)
{
    //to deal with query strings such as bbb.aspx?aaa=1
    if(strFilePath.Contains('?'))
        strFilePath = strFilePath.Substring(0, strFilePath.IndexOf('?'));

    //the list of valid extensions
    string[] astrValidExtensions = { ".aspx", ".asp" };

    //returns true if the extension of the file path is found in the 
    //list of valid extensions
    return astrValidExtensions.Contains(
        System.IO.Path.GetExtension(strFilePath));
}