System.Globalization.TextInfo.ToLower C# (CSharp) Method

        public unsafe virtual String ToLower(String str) 
        {
            if (str == null) { throw new ArgumentNullException("str"); }
            
            
            return (nativeChangeCaseString(m_textInfoID, m_pNativeTextInfo, str, false));
        }

        /// <summary>
        /// Converts given string to first letter to upper and others to lower. Returns null if value is null.
        /// </summary>
        /// <param name="value">The value to be converted.</param>
        /// <param name="culture">The culture to be used while converting.</param>
        /// <returns>String</returns>
        public static string ToTitleCase(this string value, string culture = "tr-TR")
        {
            if (value.IsNull())
            {
                return(null);
            }

            value = value.Trim();
            if (value.Length > 0)
            {
                System.Globalization.CultureInfo cultureInfo = new System.Globalization.CultureInfo(culture);
                System.Globalization.TextInfo    textInfo    = cultureInfo.TextInfo;
                value = textInfo.ToLower(value);
                value = textInfo.ToTitleCase(value);
            }

            return(value);
        }