System.String.ToLower Method

Returns a copy of this string converted to lowercase, using the casing rules of the specified culture.


public string ToLower (System.Globalization.CultureInfo culture)


An object that supplies culture-specific casing rules.


The lowercase equivalent of the current string.


The casing rules of the culture specified by the culture parameter determine the way the case of the string is changed.


This method does not modify the value of the current instance. Instead, it returns a new string in which all characters in the current instance are converted to lowercase.

Security Considerations

If you pass the string.ToLower(System.Globalization.CultureInfo) method a System.Globalization.CultureInfo object other than System.Globalization.CultureInfo.InvariantCulture, the casing operation will take culture-specific rules into account. If you need the lowercase or uppercase version of an operating system identifier, such as a file name, named pipe, or registry key, use the string.ToLowerInvariant or string.ToUpperInvariant method. This produces the same result in every culture and performs more efficiently.


Namespace: System
Assembly: mscorlib (in mscorlib.dll)
Assembly Versions: 1.0.5000.0,,