不区分大小进行字符串比较

所述String.Equals（字符串，StringComparison）方法，可以指定一个StringComparison的值 StringComparison.OrdinalIgnoreCase 为不区分大小写的比较。如果为StringComparison参数指定StringComparison.OrdinalIgnoreCase值，则还有一个静态 String.Compare（String，String，StringComparison）方法将执行不区分大小写的序数比较。以下示例代码：

string root = @"C:\users";
string root2 = @"C:\Users";
bool result = root.Equals(root2, StringComparison.OrdinalIgnoreCase);
bool areEqual = String.Equals(root, root2, StringComparison.OrdinalIgnoreCase);
int comparison = String.Compare(root, root2, comparisonType: StringComparison.OrdinalIgnoreCase);
Console.WriteLine($"Ordinal ignore case: <{root}> and <{root2}> are {(result ? "equal." : "not equal.")}");
Console.WriteLine($"Ordinal static ignore case: <{root}> and <{root2}> are {(areEqual ? "equal." : "not equal.")}");
if (comparison < 0)
    Console.WriteLine($"<{root}> is less than <{root2}>");
else if (comparison > 0)
    Console.WriteLine($"<{root}> is greater than <{root2}>");
else
    Console.WriteLine($"<{root}> and <{root2}> are equivalent in order");