iOS－－小知識點（持續更新）

一. 顏色漸變

 CAGradientLayer *gradientLayer = [CAGradientLayer layer];
    gradientLayer.colors = @[(__bridge id)[UIColor whiteColor].CGColor, (__bridge id)[UIColor grayColor].CGColor, (__bridge id)[UIColor whiteColor].CGColor];
    gradientLayer.locations = @[@0.0, @0.5, @1.0];
    gradientLayer.startPoint = CGPointMake(0, 0);
    gradientLayer.endPoint = CGPointMake(1.0, 0);
    gradientLayer.frame = CGRectMake(0, 100, 300, 2);
    [self.view.layer addSublayer:gradientLayer];

二. （已刪除）

三. 使用drowRect繪製簡單圖形

//獲取上下文
    CGContextRef context=UIGraphicsGetCurrentContext();
    //設置繪製地區的顏色
    CGContextSetRGBFillColor(context, 1, 0, 0, 1);
    //設置繪製的位置和大小
    CGContextFillRect(context, CGRectMake(0, 100, 100, 100));
    NSString * text=@"文字";
    UIFont * font=[UIFont systemFontOfSize:14];
    //設置文字的位置
    [text drawAtPoint:CGPointMake(0, 200) withAttributes:font.fontDescriptor.fontAttributes];
    UIImage * img=[UIImage imageNamed:@""];
    [img drawInRect:CGRectMake(0, 300, 100, 100)];

四. 可變數組與不可變數組之間的轉換

NSMutableArray * mutablearray=[[NSMutableArray alloc]initWithCapacity:0];
    NSArray * copyarray=[mutablearray copy];
    copyarray=@[@"1",@"2",@"3"];
    NSArray * array=[[NSArray alloc]init];
    NSMutableArray * copymutablearray=[array mutableCopy];

    [copymutablearray setObject:@"加入到第一位" atIndexedSubscript:0];
    [copymutablearray addObject:@"排序加入"];
    [copymutablearray addObjectsFromArray:copyarray];

五. 快速求和，最大值，最小值，平均值

 NSArray *array = [NSArray arrayWithObjects:@"2.0", @"2.3", @"3.0", @"4.0", @"10", nil];
    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];

六. 對控件的旋轉，平移，縮放，復位

//平移
      CGAffineTransform transForm = _pingyibu.transform;
     _pingyibu.transform=CGAffineTransformTranslate(transForm, 100, 0);
    //旋轉
    _pingyibu.transform = CGAffineTransformRotate(transForm, M_PI_4);
    //縮放按鈕
    _pingyibu.transform = CGAffineTransformScale(transForm, 1.2, 1.2);
    //初始化復位
     _pingyibu.transform = CGAffineTransformIdentity;

七. 設置label的行間距

NSMutableAttributedString *attributedString =
    [[NSMutableAttributedString alloc] initWithString:_xuanzhuanla.text];
    NSMutableParagraphStyle *paragraphStyle =  [[NSMutableParagraphStyle alloc] init];
    [paragraphStyle setLineSpacing:3];
    //調整行間距
    [attributedString addAttribute:NSParagraphStyleAttributeName
                             value:paragraphStyle
                             range:NSMakeRange(0, [_xuanzhuanla.text length])];
    _xuanzhuanla.attributedText = attributedString;

八. 讓應用直接閃退

AppDelegate *app = [UIApplication sharedApplication].delegate;
    UIWindow *window = app.window;
    [UIView animateWithDuration:1.0f animations:^{
        window.alpha = 0;
    } completion:^(BOOL finished) {
        exit(0);
    }];

九. 手機震動

AudioServicesPlaySystemSound(kSystemSoundID_Vibrate);

十. 生成手機唯一ID：UUID

-(NSString*) uuid {
    CFUUIDRef puuid = CFUUIDCreate( nil );
    CFStringRef uuidString = CFUUIDCreateString( nil, puuid );
    NSString * result = (NSString *)CFBridgingRelease(CFStringCreateCopy( NULL, uuidString));
    CFRelease(puuid);
    CFRelease(uuidString);
    return result;
}

十一. label自適應高度

 CGRect rect=[la.text boundingRectWithSize:CGSizeMake(WIDTH-70, MAXFLOAT) options:NSStringDrawingUsesLineFragmentOrigin|NSStringDrawingUsesFontLeading attributes:@{NSFontAttributeName:la.font} context:nil];

十二. 使用AFN判斷網絡狀態

 NSURL *url=[NSURL URLWithString:@"http://www.apple.com"];
    AFHTTPRequestOperationManager *operationManager=[[AFHTTPRequestOperationManager alloc]initWithBaseURL:url];
    //根據不同的網絡狀態改變去做相應處理
    [operationManager.reachabilityManager setReachabilityStatusChangeBlock:^(AFNetworkReachabilityStatus status) {
               switch (status) {
            case AFNetworkReachabilityStatusReachableViaWWAN:
                [self fasongsuoyou];
                break;
            case AFNetworkReachabilityStatusReachableViaWiFi:
                       [self fasongsuoyou];
                break;
            case AFNetworkReachabilityStatusNotReachable:
                [self alert:NSLocalizedString(@"wuwangluo",@"")];
                break;
            default:
                break;
        }
    }];
    //開始監控
    [operationManager.reachabilityManager startMonitoring];

十三. image轉換成data類型

NSData *data=UIImagePNGRepresentation(image);
NSData *data=UIImageJPEGRepresentation(image, 1.0);

十四. 獲取當前時間和時間戳

//當前時間
NSDate *  senddate=[NSDate date];
        NSDateFormatter  *dateformatter=[[NSDateFormatter alloc] init];
        [dateformatter setDateFormat:@"YYYY-MM-dd HH:mm:ss"];
NSString * locationString=[dateformatter stringFromDate:senddate];
//當前時間戳
NSDate* dat = [NSDate dateWithTimeIntervalSinceNow:0];
        NSTimeInterval a=[dat timeIntervalSince1970];
        NSString *timeString = [NSString stringWithFormat:@"%f", a];
        long s = [timeString intValue];

十五. 對比時間差

-(int)max:(NSDate *)datatime
{
    //創建日期格式化對象
    NSDateFormatter *dateFormatter=[[NSDateFormatter alloc] init];
    [dateFormatter setDateFormat:@"YYYY-MM-dd hh:mm:ss"];
    NSDate *  senddate=[NSDate date];
    NSString *  locationString=[dateFormatter stringFromDate:senddate];
    NSDate *date=[dateFormatter dateFromString:locationString];
    //取兩個日期對象的時間間隔：
    //這裏的NSTimeInterval 並不是對象，是基本型，其實是double類型，是由c定義的:typedef double NSTimeInterval;
    NSTimeInterval time=[date timeIntervalSinceDate:datatime];
    int days=((int)time)/(3600*24);
    return days;
}

十六. 使提示框消失（定時）

[alu dismissWithClickedButtonIndex:0 animated:NO];

十七. 設置self.title的顏色

UIColor * color=[UIColor whiteColor];
NSDictionary * dict=[NSDictionary dictionaryWithObject:color forKey:UITextAttributeTextColor];
self.navigationController.navigationBar.titleTextAttributes = dict;

十八. 請求定位權限以及定位屬性

//定位管理器
    _locationManager=[[CLLocationManager alloc]init];
    //如果沒有授權則請求用戶授權
    if ([CLLocationManager authorizationStatus]==kCLAuthorizationStatusNotDetermined){
        [_locationManager requestWhenInUseAuthorization];
    }else if([CLLocationManager authorizationStatus]==kCLAuthorizationStatusAuthorizedWhenInUse){
        //設置代理
        _locationManager.delegate=self;
        //設置定位精度
        _locationManager.desiredAccuracy=kCLLocationAccuracyBest;
        //定位頻率,每隔多少米定位一次
        CLLocationDistance distance=10.0;//十米定位一次
        _locationManager.distanceFilter=distance;
        //啓動跟蹤定位
        [_locationManager startUpdatingLocation];
    }

十九. 通過經緯度計算距離

BOOL JuLi=NO;
    CLLocation *orig=[[CLLocation alloc] initWithLatitude:oldlat  longitude:oldlong];
    CLLocation* dist=[[CLLocation alloc] initWithLatitude:nowlat longitude:nowlong];
    CLLocationDistance kilometers=[orig distanceFromLocation:dist];
    NSLog(@"距離:%f",kilometers);
    if (kilometers>=10) {
        JuLi=YES;
    }
    else{
        JuLi=NO;
    }
    return JuLi;

二十. 彈出效果

/**
 *  彈出對話框的動畫
 *
 *  @param changeOutView 要執行的view
 *  @param dur           動畫時長
 */
-(void)exChangeOut:(UIView *)changeOutView dur:(CFTimeInterval)dur{
    CAKeyframeAnimation * animation;
    animation = [CAKeyframeAnimation animationWithKeyPath:@"transform"];
    animation.duration = dur;
    //animation.delegate = self;
    animation.removedOnCompletion = NO;
    animation.fillMode = kCAFillModeForwards;
    NSMutableArray *values = [NSMutableArray array];
    [values addObject:[NSValue valueWithCATransform3D:CATransform3DMakeScale(0.1, 0.1, 1.0)]];
    [values addObject:[NSValue valueWithCATransform3D:CATransform3DMakeScale(1.2, 1.2, 1.0)]];
    [values addObject:[NSValue valueWithCATransform3D:CATransform3DMakeScale(0.9, 0.9, 0.9)]];
    [values addObject:[NSValue valueWithCATransform3D:CATransform3DMakeScale(1.0, 1.0, 1.0)]];
    animation.values = values;
    animation.timingFunction = [CAMediaTimingFunction functionWithName: @"easeInEaseOut"];
    [changeOutView.layer addAnimation:animation forKey:nil];
}

二十一. 設置TextField左右視圖

-(id)initWithFrame:(CGRect)frame drawingLeft:(UIImageView *)icon drawingRight:(UIButton *)bu{
    self = [super initWithFrame:frame];
    if (self) {
        self.leftView = icon;
        self.leftViewMode = UITextFieldViewModeAlways;
        self.rightView= bu;
        self.rightViewMode=UITextFieldViewModeAlways;
    }
    return self;
}
-(CGRect)leftViewRectForBounds:(CGRect)bounds{
    CGRect iconRect = [super leftViewRectForBounds:bounds];
    iconRect.origin.x += 5;// 右偏10
    return iconRect;
}
-(CGRect)rightViewRectForBounds:(CGRect)bounds
{
    CGRect burect=[super rightViewRectForBounds:bounds];
    burect.origin.x +=-10;
    return burect;
}

二十二. 常用宏定義

#define PUSH(x) AppDelegate *appdelegate=(AppDelegate *)[UIApplication sharedApplication].delegate;[(UINavigationController*)appdelegate.window.rootViewController pushViewController:x animated:YES];

#define POP AppDelegate *appdelegate=(AppDelegate *)[UIApplication sharedApplication].delegate;[(UINavigationController*)appdelegate.window.rootViewController popViewControllerAnimated:YES];

#define POPROOT OGPAppDelegate *appdelegate=(OGPAppDelegate *)[UIApplication sharedApplication].delegate;[(UINavigationController*)appdelegate.window.rootViewController popToRootViewControllerAnimated:YES];

#define IOS7 ([[UIDevice currentDevice].systemVersion floatValue] >= 7.0f)
#define IPHONE_4INCH ([UIScreen mainScreen].bounds.size.height > 480.0f)

二十三. 獲取版本號提示版本更新

-(void)VersionButton
{
    NSString * string=[NSString stringWithContentsOfURL:[NSURL URLWithString:@"http://itunes.apple.com/lookup?id=??????????"] encoding:NSUTF8StringEncoding error:nil];
    if (string!=nil && [string length]>0 && [string rangeOfString:@"version"].length==7) {
        [self checkenAppUpdate:string];
    }
}
-(void)checkenAppUpdate:(NSString *)appinfo
{
    NSString * version=[[[NSBundle mainBundle] infoDictionary] objectForKey:@"CFBundleVersion"];
    NSString * appInfo1=[appinfo substringFromIndex:[appinfo rangeOfString:@"\"version\":"].location+10];
    appInfo1=[[appInfo1 substringToIndex:[appInfo1 rangeOfString:@","].location] stringByReplacingOccurrencesOfString:@"\"" withString:@""];
    if (![appInfo1 isEqualToString:version]) {
        UIAlertView * alert=[[UIAlertView alloc]initWithTitle:@"" message:[NSString stringWithFormat:@"新版本%@, 已經發布",appInfo1] delegate:self cancelButtonTitle:@"知道了" otherButtonTitles: nil];
        alert.delegate=self;
        [alert addButtonWithTitle:@"前往更新"];
        [alert show];
        alert.tag=20;
    }
}
-(void)alertView:(UIAlertView *)alertView didDismissWithButtonIndex:(NSInteger)buttonIndex
{
    if (buttonIndex==1 & alertView.tag==20) {
        NSString * url=@"https://appsto.re/cn/-naScb.i";
        [[UIApplication sharedApplication] openURL:[NSURL URLWithString:url]];
    }
}

二十四. 獲取設備或APP信息

//返回應用程序名稱
+(NSString *) getAppName{
    NSDictionary *infoDictionary = [[NSBundle mainBundle] infoDictionary];
    return [infoDictionary objectForKey:@"CFBundleDisplayName"];
}
//返回應用版本號
+(NSString *) getAppVersion{
    NSDictionary *infoDictionary = [[NSBundle mainBundle] infoDictionary];
    return [infoDictionary objectForKey:@"CFBundleShortVersionString"];
}
+(NSString *) getAppBundleVersion{
    NSDictionary *infoDictionary = [[NSBundle mainBundle] infoDictionary];
    return [infoDictionary objectForKey:@"CFBundleVersion"];
}
//設備型號
+(NSString *) getSystemName{
    return [[UIDevice currentDevice] systemName];
}
//設備版本號
+(NSString *) getSystemVersion{
    return [[UIDevice currentDevice] systemVersion];
}

二十五. 內存泄漏分析

 靜態分析內存泄露 使用Xcode自帶的Analyze功能（Product-> Analyze）（Shift + Command + B），對代碼進行靜態分析，對於內存泄露（Potential Memory Leak）, 未使用局部變量(dead store)，邏輯錯誤(Logic Flaws)以及API使用問題(API-usage)等明確的展示出來。 靜態分析的內存泄露情況比較簡單，開發者都能很快的解決。這裏不做贅述。

動態分析內存泄露 使用Xcode自帶的Profile功能（Product-> Profile）（Command + i）彈出工具框，選擇Leaks打開，選擇運行設備點左上角的Record錄製按鈕，項目就會在已選好的設備上運行，並開始錄製內存檢測情況。選Leaks查看泄露情況，在Leaks的詳細菜單Details選項裏選調用樹Call Tree，可查看所有內存泄露發生在哪些地方。再在右側的齒輪設置-Call Tree-勾選Hide System Libraries，則可直接看內存泄露發生的函數名、方法名。點擊函數名、方法名，可直接跳到函數方法的細節，可以看到哪一句代碼出現了內存泄露，以及泄露了多少內存。

接下來就要回到Xcode，找到出現內存泄露的函數方法，仔細分析如何出現的內存泄露; 一般使用ARC，按照上面一提到的內存理解和編碼習慣是不會出現內存泄露的。但我們在開發過程中，經常要使用第三方的一些類庫，特別是涉及到加密的類庫，用c或c++來編碼的加密解密方法，會出現內存泄露。此時，我們要明白這些內存分配，需要手動釋放。要一步一步看，哪裏分配了內存，在使用完之後一定要記得釋放free它。

二十六. block循環利用導致內存泄漏

A *a = [[A alloc] init]; 
a.finishBlock = ^(NSDictionary paraments){ [a doSomething]; }; 對於這種在block塊裏引用對象a的情況，要在創建對象a時加修飾符block來防止循環引用。 
block A *a = [[A alloc] init]; 
a.finishBlock = ^(NSDictionary paraments){ [a doSomething]; }; 或
 A __block a = [[A alloc] init]; a.finishBlock = ^(NSDictionary paraments){ [a doSomething]; };
 或者，需要在block中調用用self的方法、屬性、變量時，可以這樣寫
__weak typeof(self) weakSelf = self;
在block中使用weakSelf。 
__weak typeof(self) weakSelf = self;
 [b doSomethingWithFinishBlock:^{ weakSelf.text = @"內存檢測"; [weakSelf doSomething]; }];

二十七. label 的空格屬性和局部字段顏色

設置 label 的 autoresizingMask 爲 NO ,可以使用空格間隔字符串!

    NSMutableAttributedString *hintString=[[NSMutableAttributedString alloc]initWithString:@"點擊註冊按鈕服務協議"];  
    //獲取要調整顏色的文字位置,調整顏色  
    NSRange range1=[[hintString string]rangeOfString:@"註冊"];  
    [hintString addAttribute:NSForegroundColorAttributeName value:[UIColor greenColor] range:range1];  
    NSRange range2=[[hintString string]rangeOfString:@"服務協議"];  
    [hintString addAttribute:NSForegroundColorAttributeName value:[UIColor redColor] range:range2];  
    hintLabel.attributedText=hintString;

二十八. 過濾特殊字符

// 定義一個特殊字符的集合
    NSCharacterSet *set = [NSCharacterSet characterSetWithCharactersInString:
    @"@／：；（）¥「」＂、[]{}#%-*+=_\\|~＜＞$€^•'@#$%^&*()_+'\""];
    // 過濾字符串的特殊字符
    NSString *newString = [trimString stringByTrimmingCharactersInSet:set];

二十九. 設置滑動的時候隱藏 navigationbar

    第1種:
        navigationController.hidesBarsOnSwipe = Yes

    第2種:
        //1.當我們的手離開屏幕時候隱藏
    - (void)scrollViewWillEndDragging:(UIScrollView *)scrollView withVelocity:(CGPoint)velocity targetContentOffset:(inout CGPoint *)targetContentOffset
    { 
        if(velocity.y > 0) 
        {
        [self.navigationController setNavigationBarHidden:YES animated:YES];
        } else {
        [self.navigationController setNavigationBarHidden:NO animated:YES]; 
        }
    }
    velocity.y這個量，在上滑和下滑時，變化極小（小數），但是因爲方向不同，有正負之分，這就很好處理  了。

三十. 屏幕截圖

 // 1. 開啓一個與圖片相關的圖形上下文
    UIGraphicsBeginImageContextWithOptions(self.view.bounds.size,NO,0.0);
    // 2. 獲取當前圖形上下文
    CGContextRef ctx = UIGraphicsGetCurrentContext();
    // 3. 獲取需要截取的view的layer
    [self.view.layer renderInContext:ctx];
    // 4. 從當前上下文中獲取圖片
    UIImage *image = UIGraphicsGetImageFromCurrentImageContext();
    // 5. 關閉圖形上下文
    UIGraphicsEndImageContext();
    // 6. 把圖片保存到相冊
    UIImageWriteToSavedPhotosAlbum(image, nil, nil, nil);

三十一. 去掉 tabbar 和 navgationbar 的黑線

 //去掉tabBar頂部線條
    CGRect rect = CGRectMake(0, 0, 1, 1);
    UIGraphicsBeginImageContext(rect.size);
    CGContextRef context = UIGraphicsGetCurrentContext();
    CGContextSetFillColorWithColor(context, [[UIColor clearColor] CGColor]);
    CGContextFillRect(context, rect);
    UIImage *img = UIGraphicsGetImageFromCurrentImageContext();
    UIGraphicsEndImageContext();
    [self.tabBar setBackgroundImage:img];
    [self.tabBar setShadowImage:img];
    //[self.navigationController.navigationBar setBackgroundImage:img];
    //self.navigationController.navigationBar.shadowImage = ima;

    self.tabBar.backgroundColor = SLIVERYCOLOR;

三十二. 判斷字符串中是否含有中文

 -(BOOL)isChinese:(NSString *)str{
        NSString *match=@"(^[\u4e00-\u9fa5]+$)";
        NSPredicate *predicate = [NSPredicate predicateWithFormat:@"SELF matches %@", match];
        return [predicate evaluateWithObject:str];
    }

三十三. 解決父視圖和子視圖的手勢衝突問題

 /** 解決手勢衝突 */
    - (BOOL)gestureRecognizer:(UIGestureRecognizer *)gestureRecognizer shouldReceiveTouch:(UITouch *)touch{
        if ([touch.view isDescendantOfView:cicView]) {
            return NO;
        }
        return YES;
    }

三十四. 獲取當前連接的Wi-Fi的名稱

 NSString *wifiName = @"Not Found";
        CFArrayRef myArray = CNCopySupportedInterfaces();
        if (myArray != nil) {
            CFDictionaryRef myDict = CNCopyCurrentNetworkInfo(CFArrayGetValueAtIndex(myArray, 0));
            if (myDict != nil) {
                NSDictionary *dict = (NSDictionary*)CFBridgingRelease(myDict);
                wifiName = [dict valueForKey:@"SSID"];
            }
        }

三十五. 跨控制器跳轉返回

for (UIViewController *controller in self.navigationController.viewControllers) { 
        if ([controller isKindOfClass:[@“你要返回的控制器類名” class]]) {
             [self.navigationController popToViewController:controller animated:YES];
         }
     }

三十六. layer.cornerRadius 圓角流暢性的優化

loginBtn.layer.rasterizationScale = [UIScreen mainScreen].scale;

三十七. 導航欄和下方視圖間隔距離消失

self.automaticallyAdjustsScrollViewInsets=YES;

三十八. 毛玻璃效果(ios8.0以後的版本)

    UIVisualEffectView *visualEffectView = [[UIVisualEffectView alloc] initWithEffect:[UIBlurEffect effectWithStyle:UIBlurEffectStyleLight]];
    visualEffectView.frame = CGRectMake(0, 0, 320*[FlexibleFrame ratio], 180*[FlexibleFrame ratio]);
    visualEffectView.alpha = 1.0;

三十九. 移動工程不需要配置路徑

創建.pch文件時 , BuildSetting 中的 Prefix Header 中的路徑開頭可以寫 $(SRCROOT)/工程地址, 這樣寫的好處可以使你的挪動代碼不用手動更換路徑!

四十. 判斷兩個數組是否相同

 NSArray *array1 = [NSArray arrayWithObjects:@"a", @"b", @"c",  nil];
    NSArray *array2 = [NSArray arrayWithObjects:@"d", @"a", @"c",  nil];
    bool bol = false;
    //創建倆新的數組
    NSMutableArray *oldArr = [NSMutableArray arrayWithArray:array1];
    NSMutableArray *newArr = [NSMutableArray arrayWithArray:array2];
    //對數組1排序。
    [oldArr sortUsingComparator:^NSComparisonResult(id obj1, id obj2){
        return obj1 > obj2;
    }];
    //對數組2排序。
    [newArr sortUsingComparator:^NSComparisonResult(id obj1, id obj2){
        return obj1 > obj2;
    }];
    if (newArr.count == oldArr.count) {
        bol = true;
        for (int16_t i = 0; i < oldArr.count; i++) {

            id c1 = [oldArr objectAtIndex:i];
            id newc = [newArr objectAtIndex:i];

            if (![newc isEqualToString:c1]) {
                bol = false;
                break;
            }
        }
    }
    if (bol) {
        NSLog(@" ------------- 兩個數組的內容相同！");
    }
    else {
        NSLog(@"-=-------------兩個數組的內容不相同！");
    }

四十一. block

對於block，都應該使用copy來聲明，原因是block來捕獲上下文的信息 官方文檔

四十二. 使應用在後臺運行

- (void)applicationDidEnterBackground:(UIApplication *)application  
{  
    __block UIBackgroundTaskIdentifier bgTask = UIBackgroundTaskInvalid;  
    bgTask = [application beginBackgroundTaskWithExpirationHandler:^{  
        dispatch_async(dispatch_get_main_queue(), ^{  
            if (bgTask != UIBackgroundTaskInvalid) {  
                bgTask = UIBackgroundTaskInvalid;  
            }  
        });  
    }];  
    dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^{  
        dispatch_async(dispatch_get_main_queue(), ^{  
            if (bgTask != UIBackgroundTaskInvalid) {  
                bgTask = UIBackgroundTaskInvalid;  
            }  
        });  
    });  
}  

但其實不是應用一直在運行。

四十三. 計算一段NSString在視圖中渲染出來的尺寸

+ (CGSize)sizeOfString:(NSString *)textString font:(UIFont *)font bound:(CGSize)bound {  
    NSMutableParagraphStyle * paragraphStyle = [[NSMutableParagraphStyle alloc] init];  
    paragraphStyle.lineBreakMode = NSLineBreakByWordWrapping;  
    paragraphStyle.alignment = NSTextAlignmentLeft;  
    if (font == nil) {  
        font = [UIFont systemFontOfSize:[UIFont systemFontSize]];  
    }  
    NSDictionary * attributes = @{NSFontAttributeName : font,  
                                  NSParagraphStyleAttributeName : paragraphStyle};  

    NSAttributedString* attributedString = [[NSAttributedString alloc] initWithString:textString attributes:attributes];  
    return [TTTAttributedLabel sizeThatFitsAttributedString:attributedString  
                                            withConstraints:CGSizeMake(bound.width, 999)  
                                     limitedToNumberOfLines:0];  
}  

四十四. 獲取相應的字體類型名

for(NSString *fontfamilyname in [UIFont familyNames])  
{  
    NSLog(@"Family:'%@'",fontfamilyname);  
    for(NSString *fontName in [UIFont fontNamesForFamilyName:fontfamilyname])  
    {  
        NSLog(@"\tfont:'%@'",fontName);  
    }  
    NSLog(@"~~~~~~~~");  
}  

四十五. Masonry和SVProgreaaHUD需要注意

使用Masonry約束TTTAttributedLabel的時候，初始化TTTAttributedLabel需要設置frame爲CGRectZero，否則約束會不生效。
SVProgressHUD如果要自定義一些屬性，比如loading狀態轉圈的顏色，必須先設置style爲SVProgressHUDStyleCustom，這樣自定義的狀態纔會生效。

                                  ##待續！！