設(shè)置多少時間前

// 幾天前 幾分鐘前..
+ (NSString *)updateTimeForTimeInterval:(NSInteger)timeInterval {
    
    // 獲取當(dāng)前時時間戳 1466386762.345715 十位整數(shù) 6位小數(shù)
    NSTimeInterval currentTime = [[NSDate date] timeIntervalSince1970];
    // 創(chuàng)建歌曲時間戳(后臺返回的時間 一般是13位數(shù)字)
    NSTimeInterval createTime = timeInterval;
    // 時間差
    NSTimeInterval time = currentTime - createTime;
    if (time < 60) {
        return @"剛剛";
    }
    NSInteger minutes = time / 60;
    if (minutes < 60) {
        
        return [NSString stringWithFormat:@"%ld分鐘前", minutes];
    }
    // 秒轉(zhuǎn)小時
    NSInteger hours = time / 3600;
    if (hours < 24) {
        return [NSString stringWithFormat:@"%ld小時前",hours];
    }
    // 秒轉(zhuǎn)天數(shù)
    NSInteger days = time / 3600 / 24;
    if (days < 30) {
        return [NSString stringWithFormat:@"%ld天前",days];
    }
    // 秒轉(zhuǎn)月
    NSInteger months = time / 3600 / 24 / 30;
    if (months < 12) {
        return [NSString stringWithFormat:@"%ld月前",months];
    }
    // 秒轉(zhuǎn)年
    NSInteger years = time / 3600 / 24 / 30 / 12;
    return [NSString stringWithFormat:@"%ld年前",years];
}

設(shè)置多樣文本 - 關(guān)鍵字、字體大小、高亮字體罗标、字體顏色以及行間距

+ (NSAttributedString *)attStringWithString:(NSString *)string
                                    keyWord:(NSString *)keyWord
                                       font:(UIFont *)font
                           highlightedColor:(UIColor *)highlightedcolor
                                  textColor:(UIColor *)textColor
                                  lineSpace:(CGFloat)lineSpace {
    if (string.length) {
        
        NSMutableAttributedString *attStr = [[NSMutableAttributedString alloc] initWithString:string];
        if (!keyWord || keyWord.length == 0) {
            NSRange allRange = NSMakeRange(0, string.length);
            [attStr addAttribute:NSFontAttributeName value:font range:allRange];
            [attStr addAttribute:NSForegroundColorAttributeName value:textColor range:allRange];
            
            NSMutableParagraphStyle *style = [[NSMutableParagraphStyle alloc] init];
            style.lineSpacing = lineSpace;
            [attStr addAttribute:NSParagraphStyleAttributeName value:style range:allRange];
            return attStr;
        }
        NSRange range = [string rangeOfString:keyWord options:NSCaseInsensitiveSearch];
        // 找到了關(guān)鍵字
        if (range.location != NSNotFound) {
            NSRange allRange = NSMakeRange(0, string.length);
            [attStr addAttribute:NSFontAttributeName value:font range:allRange];
            [attStr addAttribute:NSForegroundColorAttributeName value:textColor range:allRange];
            [attStr addAttribute:NSForegroundColorAttributeName value:highlightedcolor range:range];
            
            NSMutableParagraphStyle *style = [[NSMutableParagraphStyle alloc] init];
            style.lineSpacing = lineSpace;
            [attStr addAttribute:NSParagraphStyleAttributeName value:style range:allRange];
        } else {
            NSRange allRange = NSMakeRange(0, string.length);
            [attStr addAttribute:NSFontAttributeName value:font range:allRange];
            [attStr addAttribute:NSForegroundColorAttributeName value:textColor range:allRange];
            
            NSMutableParagraphStyle *style = [[NSMutableParagraphStyle alloc] init];
            style.lineSpacing = lineSpace; 
            [attStr addAttribute:NSParagraphStyleAttributeName value:style range:allRange];
            return attStr;
        }
        return attStr.copy;
    }
    return [[NSAttributedString alloc] init];
}

判斷是否為空字符串

/**
 *  判斷字符串是否為空
 */
+ (BOOL)isBlankString:(NSString *)string {
    
    if (string == nil || string == NULL) {
        return YES;
    }
    if ([string isKindOfClass:[NSNull class]]) {
        return YES;
    }
    if ([string isKindOfClass:[NSDictionary class]]) {
        return YES;
    }
    if ([string isKindOfClass:[NSString class]] == NO) {
        return YES;
    }
    if ([[string stringByTrimmingCharactersInSet:[NSCharacterSet whitespaceCharacterSet]] length] == 0) {
        return YES;
    }
    if ([string isEqualToString:@""]) {
        return YES;
    }
    return NO;
}

把顏色轉(zhuǎn)換成圖片

+(UIImage *)imageWithColor:(UIColor *)color
{
    //1.設(shè)定圖片大小
    CGRect rect = CGRectMake(0.0f, 0.0f, 1.0f, 1.0f);
    //2.開始圖片上下文
    UIGraphicsBeginImageContext(rect.size);
    //3.拿到當(dāng)前上下文
    CGContextRef context = UIGraphicsGetCurrentContext();
    //4.設(shè)置上下文顏色
    CGContextSetFillColorWithColor(context,color.CGColor);
    //5.填充上下文
    CGContextFillRect(context, rect);
    //6.從當(dāng)前圖片上下文獲取圖片
    UIImage * image = UIGraphicsGetImageFromCurrentImageContext();
    //7.圖片上下文
    UIGraphicsEndImageContext();
    return image;
}

以上幾點是我在別人的項目中新學(xué)到的知識點，以后會分享更多！