iOS-将“2018-08-13T17:40:51.733+0000”格式的date转换成正常格式date

传入2018-08-13T17:40:51.733+0000格式，返回正常格式

+ (NSDate *)timeStringToDate:(NSDate *)fromDate {

    NSString * formatterString = @"yyyy-MM-dd HH:mm:ss";

    // DateFormatter, Calendar初始化比较消耗内存, 定义成单例 

    [MHDateFormatter sharedFormatter].dateFormat = formatterString;

    // 指定区域，真机一定要指定 

    [MHDateFormatter sharedFormatter].locale = [NSLocale localeWithLocaleIdentifier: @"en"];

    //转换成常用格式字符串

     NSString *dateString = [[MHDateFormatter sharedFormatter] stringFromDate:fromDate];

   再将常用格式的字符串转成date

    return [[MHDateFormatter sharedFormatter] dateFromString: dateString];

}