iOS 两行终端命令计算代码量

cd /Users/yinlinqvan/iOS/我的企业级项目/201703善林金 融/亿宝贷借款/xjd_llzf/SLCashLoan/SLCashLoan

find . "(" -name "*.m" -or -name "*.mm" -or -name "*.cpp" -or -name "*.h" -or -name "*.rss" ")" -print | xargs wc -l

语法糖

1. 字面量语法
   @1
@[@"1", @"2"]
@{@"key": @"value"}
(CGRect){0, 0, 100, 100}
(CGPoint){100, 100}
2. 可视化格式语言vfl

/**
 设置活动指示器约束
 */
- (void)setupActivityIndicatorView {
    _activityIndicatorView = [[UIActivityIndicatorView alloc] initWithActivityIndicatorStyle:UIActivityIndicatorViewStyleWhiteLarge];
    [_activityIndicatorView setColor:kActivityIndicatorViewColor];
    [_activityIndicatorView setHidesWhenStopped:YES];
    [self.view addSubview:_activityIndicatorView];
    
    [_activityIndicatorView setTranslatesAutoresizingMaskIntoConstraints:NO];
    NSDictionary *views = @{@"activityIndicatorView": _activityIndicatorView};
    NSString *visualFormatLanguage = @"|-[activityIndicatorView]-|";//可视化格式语言vfl
    NSArray *contraintsX = [NSLayoutConstraint constraintsWithVisualFormat:visualFormatLanguage options:NSLayoutFormatAlignAllCenterX metrics:nil views:views];
    [self.view addConstraints:contraintsX];
    
    NSArray *contraintsY = [NSLayoutConstraint constraintsWithVisualFormat:@"V:|-[activityIndicatorView]-|" options:NSLayoutFormatAlignAllCenterY metrics:nil views:views];
    [self.view addConstraints:contraintsY];
}

悬停按钮

固定约束

UITextField

textfield.text可能是空字符串，也可能是nil

iOS Reavel

• 对所有出现的崩溃的数据都要进行判空处理，要负责任
• 查找常量重复（const修饰）

连接文件服务器

• 打开finder > 前往（快捷键：command + K）
• 服务器地址：smb://192.168.188.19

键盘高度

- (void)keyboardWillShow:(NSNotification *)aNotification {
    //呼出键盘
    NSDictionary *userInfo = [aNotification userInfo];
    NSValue *aValue = [userInfo objectForKey:UIKeyboardFrameEndUserInfoKey];
    CGRect keyboardRect = [aValue CGRectValue];
    _keyboardH = keyboardRect.size.height;
}

打印日志

#ifdef DEBUG  
#define NSLog(...) NSLog(__VA_ARGS__)  
#define debugMethod() NSLog(@"%s", __func__)  
#else  
#define NSLog(...)  
#define debugMethod()  
#endif  

Universal Links通用链接

http://www.jianshu.com/p/693459b618e5

格式化%zd 解决整型警告

respondsToSelector:

https://segmentfault.com/q/1010000004682116

钥匙串

colorset

PDFKit

.archive

比如国家、省份、城市、区县、街道直接归档，解决卡顿

代码方式调整屏幕亮度

// brightness属性值在0-1之间，0代表最小亮度，1代表最大亮度
[[UIScreen mainScreen] setBrightness:0.5];

通知监听APP生命周期

1. UIApplicationDidEnterBackgroundNotification 应用程序进入后台
2. UIApplicationWillEnterForegroundNotification 应用程序将要进入前台
3. UIApplicationDidFinishLaunchingNotification 应用程序完成启动
4. UIApplicationDidFinishLaunchingNotification 应用程序由挂起变的活跃
5. UIApplicationWillResignActiveNotification 应用程序挂起(有电话进来或者锁屏)
6. UIApplicationDidReceiveMemoryWarningNotification 应用程序收到内存警告
7. UIApplicationDidReceiveMemoryWarningNotification 应用程序终止(后台杀死、手机关机等)
8. UIApplicationSignificantTimeChangeNotification 当有重大时间改变(凌晨0点，设备时间被修改，时区改变等)
9. UIApplicationWillChangeStatusBarOrientationNotification 设备方向将要改变
10. UIApplicationDidChangeStatusBarOrientationNotification 设备方向改变
11. UIApplicationWillChangeStatusBarFrameNotification 设备状态栏frame将要改变
12. UIApplicationDidChangeStatusBarFrameNotification 设备状态栏frame改变
13. UIApplicationBackgroundRefreshStatusDidChangeNotification 应用程序在后台下载内容的状态发生变化
14. UIApplicationProtectedDataWillBecomeUnavailable 本地受保护的文件被锁定,无法访问
15. UIApplicationProtectedDataWillBecomeUnavailable 本地受保护的文件可用了

常用Git操作

1. 切换用户
2. 新建分支
3. 切换分支
4. 关联远程仓库

iOS App Store 审核被拒

1、禁用版本更新按钮
2、隐私权限详细说明
3、隐私权限使用入口
4、后台获取隐私权限必要性说明必须在备注中说明
5、看门狗wactchdog崩溃，AppDelegate删掉同步请求，或改用异步请求版本信息
https://developer.apple.com/library/content/qa/qa1693/_index.html

当UITextView/UITextField中没有文字时，禁用回车键

textField.enablesReturnKeyAutomatically = YES;

从导航控制器中删除某个控制器

NSMutableArray *navigationArray = [[NSMutableArray alloc] initWithArray: self.navigationController.viewControllers];
[navigationArray removeObjectAtIndex: 2]; 
self.navigationController.viewControllers = navigationArray;

将一个view保存为pdf格式

- (void)createPDFfromUIView:(UIView*)aView saveToDocumentsWithFileName:(NSString*)aFilename {
    NSMutableData *pdfData = [NSMutableData data];
    UIGraphicsBeginPDFContextToData(pdfData, aView.bounds, nil);
    UIGraphicsBeginPDFPage();
    CGContextRef pdfContext = UIGraphicsGetCurrentContext();
    [aView.layer renderInContext:pdfContext];
    UIGraphicsEndPDFContext();

    NSArray* documentDirectories = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask,YES);
    NSString* documentDirectory = [documentDirectories objectAtIndex:0];
    NSString* documentDirectoryFilename = [documentDirectory stringByAppendingPathComponent:aFilename];
    [pdfData writeToFile:documentDirectoryFilename atomically:YES];
    NSLog(@"documentDirectoryFileName: %@",documentDirectoryFilename);
}

判断两个区域是否有重合

if (CGRectIntersectsRect(rect1, rect2)) {
}

查看系统所有字体

for (id familyName in [UIFont familyNames]) {
    NSLog(@"%@", familyName);
    for (id fontName in [UIFont fontNamesForFamilyName:familyName]) NSLog(@"  %@", fontName);
}

添加.pch文件

1. 创建新文件 ios->other->PCH file，创建一个pch文件：“工程名-Prefix.pch”
2. 将building setting中的precompile header选项的路径添加“$(SRCROOT)/项目名称/pch文件名”（例如：$(SRCROOT)/项目名称/工程名-Prefix.pch）
3. 将Precompile Prefix Header为YES，预编译后的pch文件会被缓存起来，可以提高编译速度

私有API（不能用）

1. 点击Home键的效果（程序挂起）：[[UIApplication sharedApplication] performSelector:@selector(suspend)];

UIWebView高度

- (void)webViewDidFinishLoad:(UIWebView *)webView {
    CGFloat height = [[webView stringByEvaluatingJavaScriptFromString:@"document.body.offsetHeight"] floatValue];      CGRect frame = webView.frame;
    webView.frame = CGRectMake(frame.origin.x, frame.origin.y, frame.size.width, height);
}

数据库操作：增、删、改、查

1. 增：insert into tb_blogs(name, url) values('aaa','http://www.baidu.com');
2. 删：delete from tb_blogs where blogid = 1;
3. 改：update tb_blogs set url = 'www.baidu.com' where blogid = 1;
4. 查：select name, url from tb_blogs where blogid = 1;
5. 联表查询

数组逆序遍历

NSArray *array = @[@"1",@"2",@"3",@"5",@"6"];
[array enumerateObjectsWithOptions:NSEnumerationReverse usingBlock:^(id  _Nonnull obj, NSUInteger idx, BOOL * _Nonnull stop) {
NSLog(@"%@",obj);
}];

数组遍历

[self.navigationController.childViewControllers enumerateObjectsUsingBlock:^(__kindof UIViewController * _Nonnull obj, NSUInteger idx, BOOL * _Nonnull stop) {
    if ([obj isKindOfClass:NSClassFromString(@"SLCashLoanViewController")] || [obj isKindOfClass:NSClassFromString(@"SLCreditLoanViewController")] || [obj isKindOfClass:NSClassFromString(@"SLAccountViewController")]) {
        [self.navigationController popToViewController:obj animated:YES];
        *stop = YES;
    }
}];

禁用复制粘贴菜单

- (BOOL)canPerformAction:(SEL)action withSender:(id)sender {
    if ([UIMenuController sharedMenuController]) {
        [UIMenuController sharedMenuController].menuVisible = NO;
    }
    return NO;
}

设置展位文本字体颜色大小

UITextField *textField = [[UITextField alloc] initWithFrame:(CGRect){0, 0, 200, 44}];
textField.placeholder = @"请输入用户名";
[textField setValue:[UIColor redColor] forKeyPath:@"_placeholderLabel.textColor"];
[textField setValue:[UIFont boldSystemFontOfSize:16] forKeyPath:@"_placeholderLabel.font"];

富文本库

设置状态栏样式

- (UIStatusBarStyle)preferredStatusBarStyle {
    return  UIStatusBarStyleLightContent;
}

edgesForExtendedLayout

因为一般为了不让tableView 不延伸到 navigationBar 下面， 属性设置为 UIRectEdgeNone。这时会发现导航栏变灰了，处理如下就OK了
self.navigationController.navigationBar.translucent = NO;

当automaticallyAdjustsScrollViewInsets为NO时，tableview 是从屏幕的最上边开始，也就是被导航栏、状态栏覆盖。
automaticallyAdjustsScrollViewInsets为YES时，tableView 上下滑动时，是可以穿过导航栏、状态栏的，在他们下面有淡淡的浅浅红色。

extendedLayoutIncludesOpaqueBars首先看下官方解释，默认 NO， 但是Bar 的默认属性是 透明的。也就是说只有在不透明下才有用但是，测试结果很软肋，基本区别不大。但是对于解决一些Bug 是还是起作用的，比如说SearchBar的跳动问题。

iOS 设置状态栏

设置导航栏在滑动时高度约束改为20，则状态栏就可以显示导航栏的图片部分

iOS UITabBarController切换选项卡，关闭模态视图回到主视图

从任意页面，切换选项卡
关闭模态视图回到主视图

//跳转并切换选项卡
dispatch_async(dispatch_get_main_queue(), ^{
    [self.navigationController popToRootViewControllerAnimated:NO];
    SLTabBarController *tabC = (SLTabBarController *)[UIApplication sharedApplication].keyWindow.rootViewController;
    tabC.selectedIndex= 1;
});

iOS 获取UIWebView的高度

/**
 获取UIWebView的高度

 @param webView UIWebView
 */
- (void)webViewDidFinishLoad:(UIWebView *)webView  {
    CGFloat height = [[webView stringByEvaluatingJavaScriptFromString:@"document.body.offsetHeight"] floatValue];
    CGRect frame = webView.frame;
    webView.frame = CGRectMake(frame.origin.x, frame.origin.y, frame.size.width, height);
}

iOS UUID(AdSupport )

+ (NSString *)getUUIDString {
    CFUUIDRef uuidRef = CFUUIDCreate(kCFAllocatorDefault);
    CFStringRef strRef = CFUUIDCreateString(kCFAllocatorDefault , uuidRef);
    NSString *uuidString = (__bridge NSString*)strRef;
    CFRelease(strRef);
    CFRelease(uuidRef);
    [SLFileCacheManager saveUserData:uuidString forKey:@"uuid"];
    return uuidString;
}

iOS 获取设备名称

[[UIDevice currentDevice] name]

iOS ADID

[[[ASIdentifierManager sharedManager] advertisingIdentifier] UUIDString]]

iOS 数据精度

- (void)useNSDecimalNumber {
    int unit = 10000;//万
    CGFloat money = 10000000.1;
    NSDecimalNumber *moneyDecimalNumber = [[NSDecimalNumber alloc] initWithFloat:money];
    CGFloat f = [NSString stringWithFormat:@"%.2f", money/unit].floatValue;//10.00万
    NSDecimalNumber *dn = [[NSDecimalNumber alloc] initWithFloat:f];
    NSLog(@"===%@是%@万", moneyDecimalNumber, dn);
}

iOS 评分

 [[UIApplicationsharedApplication]openURL:[NSURLURLWithString:@"http://itunes.apple.com/WebObjects/MZStore.woa/wa/viewContentsUserReviews?id=APPID&pageNumber=0&sortOrdering=2&type=Purple+Software&mt=8"]];

懒加载与重写setter、getter方法

• 懒加载

- (NSArray *)data {
    if (!_data) {
        _data = [NSArray arrayWithContentsOfFile:
[[NSBundle mainBundle] pathForResource:@"data" ofType:@"plist"]];
    }
    return _data;
}

自动生成技术文档headerdoc

# shell script goes here
mkdir ~/Desktop/SLHeaderdoc/Class
find /Users/shanlin/Desktop/现金贷/xjd/SLCashLoan/SLCashLoan/Class/ -name \*.h -print | xargs headerdoc2html -o ~/Desktop/SLHeaderdoc/
gatherheaderdoc ~/Desktop/SLHeaderdoc/ index.html
exit 0

headerdoc.jpg