System.IO.FileInfo不区分大小写

Question

下面是一些代码，我修改，最初从这里复制：

http://msdn.microsoft.com/en-us/library/bb546159.aspx

我正在寻找一个目录文件名和除了我想不出它工作正常如何使它区分大小写

System.IO.DirectoryInfo dir = new System.IO.DirectoryInfo(startFolder); 

// This method assumes that the application has discovery permissions 
// for all folders under the specified path. 
IEnumerable<System.IO.FileInfo> fileList = dir.GetFiles("*.*", System.IO.SearchOption.AllDirectories); 

//Create the query 
IEnumerable<System.IO.FileInfo> fileQuery = 
    from file in fileList 
    where file.Extension == ".pdf" 
    where file.Name.Contains(searchString, StringComparison.OrdinalIgnoreCase) 
    orderby file.Name 
    select file; 

此行包含错误：

where file.Name.Contains(searchString, StringComparison.OrdinalIgnoreCase) 

的错误是：

Error 1 'string' does not contain a definition for 'Contains' and the best extension method overload 'System.Linq.ParallelEnumerable.Contains<TSource>(System.Linq.ParallelQuery<TSource>, TSource, System.Collections.Generic.IEqualityComparer<TSource>)' has some invalid arguments C:\Users\k5opjdjc\Documents\Visual Studio 2013\Projects\Test_File_Search\Test_File_Search\Controllers\SearchController.cs 30 23 Test_File_Search 

...我已经寻找了几个小时，现在并不能找到答案。如果有人能够帮助，我会非常感激。

Answer 1

这应该做的伎俩：

where file.Name.IndexOf(searchString, StringComparison.CurrentCultureIgnoreCase) >= 0 

（IndexOf返回-1时，没有匹配的子被发现）