1.）设置Label字体不同颜色

// string 为要改变颜色的字段
- (void)setDifferentColorWithLabel:(UILabel *)label string:(NSString *)string {
    NSMutableAttributedString *noteStr =[[NSMutableAttributedString alloc]initWithString:label.text];
    NSRange stringRange = NSMakeRange([[noteStr string] rangeOfString:string].location, [[noteStr string] rangeOfString:string].length);
    [noteStr addAttribute:NSForegroundColorAttributeName value:[UIColor redColor] range:stringRange];
    //改变特定字段的大小
    [noteStr addAttribute:NSFontAttributeName value:[UIFont systemFontOfSize:17] range:stringRange];
    
    [label setAttributedText:noteStr];
    [label sizeToFit];
}

2.) 数组内计算

- (void)calculateInArray:(NSArray *)array {
    CGFloat sum = [[array valueForKeyPath:@"@sum.floatValue"] floatValue];
    CGFloat avg = [[array valueForKeyPath:@"@avg.floatValue"] floatValue];
    CGFloat max =[[array valueForKeyPath:@"@max.floatValue"] floatValue];
    CGFloat min =[[array valueForKeyPath:@"@min.floatValue"] floatValue];
    NSLog(@"%f\n%f\n%f\n%f",sum,avg,max,min);
}

3.) 判断是否是整形

- (BOOL)isIntClass:(NSString *)string {
    string = [string stringByTrimmingCharactersInSet:[NSCharacterSet decimalDigitCharacterSet]];
    if(string.length > 0){
        return NO;
    }
    return YES;  
}

4.) 多个字符一起切割字符串

    //以a和c分割字符串
    [self divideString:@"tingabcdefghiajklmnopcqrstuvwxayz" words:@"ac"];

- (NSArray *)divideString:(NSString *)string words:(NSString *)str {
    NSCharacterSet *set =[NSCharacterSet characterSetWithCharactersInString:str];
    NSArray *array0 =[string componentsSeparatedByCharactersInSet:set];
    return array0 ;
}

5.) 将十六进制的颜色转换为UIColor

+ (UIColor *)getColor:(NSString *)str {
    NSString *cString = [[str stringByTrimmingCharactersInSet:[NSCharacterSet whitespaceAndNewlineCharacterSet]] uppercaseString];
    if ([cString length] < 6){
        return [UIColor clearColor];
    }
    if ([cString hasPrefix:@"0X"])
        cString = [cString substringFromIndex:2];
    if ([cString hasPrefix:@"#"])
        cString = [cString substringFromIndex:1];
    if ([cString length] != 6)
        return [UIColor clearColor];
    NSRange range;
    range.location = 0;
    range.length = 2;
    //r
    NSString *rString = [cString substringWithRange:range];
    //g
    range.location = 2;
    NSString *gString = [cString substringWithRange:range];
    //b
    range.location = 4;
    NSString *bString = [cString substringWithRange:range];
    
    unsigned int r, g, b;
    [[NSScanner scannerWithString:rString] scanHexInt:&r];
    [[NSScanner scannerWithString:gString] scanHexInt:&g];
    [[NSScanner scannerWithString:bString] scanHexInt:&b];
    
    return [UIColor colorWithRed:((float) r / 255.0f) green:((float) g / 255.0f) blue:((float) b / 255.0f) alpha:1.0f];
}

6.) 比较日期大小

/************
 日期格式请传入：2016-11-30 12:12:12；如果修改日期格式，比如：2013-08-05，则将[df setDateFormat:@"yyyy-MM-dd HH:mm:ss"];修改为[df setDateFormat:@"yyyy-MM-dd"];
 ***********/
+ (int)compareDate:(NSString*)date01 withDate:(NSString*)date02{
    int value;
    NSDateFormatter *df = [[NSDateFormatter alloc]init];
    [df setDateFormat:@"yyyy-MM-dd HH:mm:ss"];
    NSDate *dt1 = [[NSDate alloc]init];
    NSDate *dt2 = [[NSDate alloc]init];
    dt1 = [df dateFromString:date01];
    dt2 = [df dateFromString:date02];
    NSComparisonResult result = [dt1 compare:dt2];
    switch (result) {
            //date02比date01大
        case NSOrderedAscending:
            value=1;break;
            //date02比date01小
        case NSOrderedDescending:
            value=-1;break;
            //date02=date01
        case NSOrderedSame:
            value=0;break;
        default:
            NSLog(@"erorr dates %@, %@", dt2, dt1);break;
    }
    return value;
}

7.) 将日期转化为周天数

//传入的是 2017-05-06 格式的字符串 若是已经格式化的，请去掉下面格式化的代码
+ (NSString*)getWeekDay:(NSString*)currentStr{
    
    NSDateFormatter* dateFormat = [[NSDateFormatter alloc]init];
    
    [dateFormat setDateFormat:@"yyyy-MM-dd"];
    
    NSDate*date =[dateFormat dateFromString:currentStr];
    
    NSArray*weekdays = @[@"周日",@"周一",@"周二",@"周三",@"周四",@"周五",@"周六"];
    
    NSCalendar*calendar = [[NSCalendar alloc]initWithCalendarIdentifier:NSCalendarIdentifierGregorian];
    
    NSTimeZone*timeZone = [[NSTimeZone alloc]initWithName:@"Asia/Shanghai"];
    
    [calendar setTimeZone: timeZone];
    
    NSCalendarUnit calendarUnit =NSCalendarUnitWeekday;
    
    NSDateComponents*theComponents = [calendar components:calendarUnit fromDate:date];
    
    return[weekdays objectAtIndex:theComponents.weekday-1];
    
}

8.) 弹出透明VC

//方法一
- (void)presentClearVCMthod1{
    TestVC1* testVC1 =[[TestVC1 alloc]init];
    [self addChildViewController:testVC1];
    testVC1.string =@"Mars";
//    若这里的传值写在设置frame之后，将在viewload里接收不到，因为先viewdidload先执行，后传值
    testVC1.view.frame =CGRectMake(0, 0,ScreenW, ScreenH);
//    ScreenW,ScreenH 为屏宽高的宏。
    [self.view addSubview:testVC1.view];
}
//方法二
//将animated设为NO就有弹框的效果
- (void)presentClearVCMethod2 {
    TestVC2 *testVC2 = [[TestVC2 alloc]init];
    self.definesPresentationContext =YES;
    testVC2.modalPresentationStyle =UIModalPresentationOverCurrentContext;
    [self presentViewController:testVC2 animated:NO completion:nil];
}

9.) 计算文件夹大小

//遍历文件夹获得文件夹大小，返回单位为 M
- (float)folderSizeAtPath:(NSString*)folderPath{
    NSFileManager* manager = [NSFileManager defaultManager];
    if (![manager fileExistsAtPath:folderPath]) return 0;
    NSEnumerator *childFilesEnumerator = [[manager subpathsAtPath:folderPath] objectEnumerator];
    NSString* fileName;
    long long folderSize = 0;
    while ((fileName = [childFilesEnumerator nextObject]) != nil){
        NSString* fileAbsolutePath = [folderPath stringByAppendingPathComponent:fileName];
        folderSize += [self fileSizeAtPath:fileAbsolutePath];
    }
    return folderSize/(1024.0*1024.0);
}
- (long long) fileSizeAtPath:(NSString*) filePath{
    NSFileManager* manager = [NSFileManager defaultManager];
    if ([manager fileExistsAtPath:filePath]){
        return [[manager attributesOfItemAtPath:filePath error:nil] fileSize];
    }
    return 0;
}

10.) APP内拨打电话

- (void)dailPhone:(NSString *)phoneNum {
    NSString * str=[[NSString alloc] initWithFormat:@"telprompt://%@",phoneNum];
//ios 10
    [[UIApplication sharedApplication] openURL:[NSURL URLWithString:str]];
//ios 10 之后
[[UIApplication sharedApplication]openURL:[NSURL URLWithString:url] options:@{UIApplicationOpenURLOptionsSourceApplicationKey : @YES} completionHandler:^(BOOL success) {

//成功后的回调

            if (!success) {

//失败后的回调

            }

}];
}

11.) 跳转到设置界面

- (void)gotoSettingPage {
    NSURL * url = [NSURL URLWithString:UIApplicationOpenSettingsURLString];
        if([[UIApplication sharedApplication] canOpenURL:url]) {
            NSURL*url =[NSURL URLWithString:UIApplicationOpenSettingsURLString];
            [[UIApplication sharedApplication] openURL:url];      
        }
}

12.) 检测字符串是否包含表情

+ (BOOL)stringContainsEmoji:(NSString *)string{
    __block BOOL returnValue = NO;
    
    [string enumerateSubstringsInRange:NSMakeRange(0, [string length])
                               options:NSStringEnumerationByComposedCharacterSequences
                            usingBlock:^(NSString *substring, NSRange substringRange, NSRange enclosingRange, BOOL *stop) {
                                const unichar hs = [substring characterAtIndex:0];
                                if (0xd800 <= hs && hs <= 0xdbff) {
                                    if (substring.length > 1) {
                                        const unichar ls = [substring characterAtIndex:1];
                                        const int uc = ((hs - 0xd800) * 0x400) + (ls - 0xdc00) + 0x10000;
                                        if (0x1d000 <= uc && uc <= 0x1f77f) {
                                            returnValue = YES;
                                        }
                                    }
                                } else if (substring.length > 1) {
                                    const unichar ls = [substring characterAtIndex:1];
                                    if (ls == 0x20e3) {
                                        returnValue = YES;
                                    }
                                    
                                } else {
                                    if (0x2100 <= hs && hs <= 0x27ff) {
                                        returnValue = YES;
                                    } else if (0x2B05 <= hs && hs <= 0x2b07) {
                                        returnValue = YES;
                                    } else if (0x2934 <= hs && hs <= 0x2935) {
                                        returnValue = YES;
                                    } else if (0x3297 <= hs && hs <= 0x3299) {
                                        returnValue = YES;
                                    } else if (hs == 0xa9 || hs == 0xae || hs == 0x303d || hs == 0x3030 || hs == 0x2b55 || hs == 0x2b1c || hs == 0x2b1b || hs == 0x2b50) {
                                        returnValue = YES;
                                    }else if (hs == 0x200d){
                                        returnValue = YES;
                                    }
                                }
                            }];
    
    return returnValue;
}

13.) 删除NSUserDefaults所有记录

//方法一
  NSString *appDomain = [[NSBundle mainBundle] bundleIdentifier];
 [[NSUserDefaults standardUserDefaults] removePersistentDomainForName:appDomain];   
 //方法二  
- (void)resetDefaults {   
  NSUserDefaults * defs = [NSUserDefaults standardUserDefaults];
     NSDictionary * dict = [defs dictionaryRepresentation];
     for (id key in dict) {
          [defs removeObjectForKey:key];
     }
      [defs synchronize];
 }
// 方法三
[[NSUserDefaults standardUserDefaults] setPersistentDomain:[NSDictionary dictionary] forName:[[NSBundle mainBundle] bundleIdentifier]];

14.) 禁止屏幕睡眠

//APP内长时间不接触屏幕会锁屏，有些需求需要保持屏幕常亮，比如播放视频等
[[UIApplication sharedApplication] setIdleTimerDisabled:YES];

15.) 修改占位符的属性

//方法一
[textField setValue:[UIColor redColor] forKeyPath:@"_placeholderLabel.textColor"];
[textField setValue:[UIFont boldSystemFontOfSize:16] forKeyPath:@"_placeholderLabel.font"];

//方法二
   NSDictionary *dic=@{NSForegroundColorAttributeName:[UIColor redColor],NSFontAttributeName:[UIFont boldSystemFontOfSize:16]};
    textField.attributedPlaceholder=[[NSAttributedString alloc]initWithString:@"请输入手机号/账号" attributes:Dic];

16.) 压缩图片

- (NSData *)imageWithImage:(UIImage*)image scaledToSize:(CGSize)newSize {
    UIGraphicsBeginImageContext(newSize);
    [image drawInRect:CGRectMake(0,0,newSize.width,newSize.height)];
    UIImage* newImage = UIGraphicsGetImageFromCurrentImageContext();
    UIGraphicsEndImageContext();
    return UIImageJPEGRepresentation(newImage, 0.8);
}

17.) 随机生成指定位数的数字和字母的组合字符串

- (NSString *)getRandomStringWithNum:(NSInteger)num {
    NSString *string = [[NSString alloc]init];
    for (int i = 0; i < num; i++) {
        int number = arc4random() % 36;
        if (number < 10) {
            int figure = arc4random() % 10;
            NSString *tempString = [NSString stringWithFormat:@"%d", figure];
            string = [string stringByAppendingString:tempString];
        }else {
            int figure = (arc4random() % 26) + 97;
            char character = figure;
            NSString *tempString = [NSString stringWithFormat:@"%c", character];
            string = [string stringByAppendingString:tempString];
        }
    }
    return string;
}

18.) 获取APP相关信息

//获取版本号
    NSString *version=[[[NSBundle mainBundle] infoDictionary] objectForKey:@"CFBundleShortVersionString"];
//获取Build号
    NSString *build=[[[NSBundle mainBundle] infoDictionary] objectForKey:@"CFBundleVersion"];
//获取设备的UUID
    NSString *identifierForVendor = [[UIDevice currentDevice].identifierForVendor UUIDString];