iOS 零碎知识点汇总

记录一下零碎的知识点，不定时更新

算是 Android 零碎知识点汇总 的兄弟篇吧

控件相关

通用

// 设置圆角

<span style="font-size:12px;">myLabel.layer.cornerRadius = 8; // 弧度
myLabel.layer.masksToBounds = YES;// 子视图如果超过了当前视图的区域，超出的部分就会被裁掉</span>

// 设置边框

<span style="font-size:12px;">myLabel.layer.borderWidth = 0.5f; // 边框粗细
myLabel.layer.borderColor = [UIColor grayColor].CGColor; // 边框颜色<strong>
</strong></span>

// 阴影

<span style="font-size:12px;">// drop shadow
[myLabel.layer setShadowColor:[UIColor blackColor].CGColor];
[myLabel.layer setShadowOpacity:0.8];
[myLabel.layer setShadowRadius:3.0];
[myLabel.layer setShadowOffset:CGSizeMake(2.0, 2.0)];</span>

UILabel 

// 设置文本删除线

myLabel.attributedText = [[NSAttributedString alloc] initWithString:@"测试数据" attributes:@{NSStrikethroughStyleAttributeName:@(NSUnderlineStyleSingle)}];

// 显示HTML字符串

NSString *htmlString = @"html字符串'"
NSAttributedString *attrStr = [[NSAttributedString alloc] initWithData:[htmlString dataUsingEncoding:NSUnicodeStringEncoding] options:@{ NSDocumentTypeDocumentAttribute: NSHTMLTextDocumentType } documentAttributes:nil error:nil];
myLabel.attributedText = attrStr;

// 文本位置

myLabel.textAlignment = NSTextAlignmentCenter; // 居中，还可以居于左右

// 内容偏移，对应X轴，Y轴，Z轴

myLabel.layer.sublayerTransform = CATransform3DMakeTranslation(5.0f, 0.0f, 0.0f);

// 自适应内容行数

myLabel.numberOfLines = 0;
[myLabel sizeToFit];

UITextField 

// 设置 placeholder 颜色

tfPhone.attributedPlaceholder = [[NSAttributedString alloc] initWithString:@"text" attributes:@{NSForegroundColorAttributeName:[UIColor blueColor]}];

UIImageView 

// 图片拉伸，使用 stretchableImageWithLeftCapWidth:AAA topCapHeight:BBB 

// 注意拉伸的位置为 左起AAA+1 位置1像素，以及上起BBB+1的位置1像素，其它位置像素不变

imgBg.image = [[UIImage imageNamed:@"loading.jpg"] stretchableImageWithLeftCapWidth:1 topCapHeight:1];

UIScrollView

// 不显示左右滚动条
scrollView.showsHorizontalScrollIndicator = NO;
// 不显示上下滚动条
scrollView.showsVerticalScrollIndicator = NO;
// 按页滑动
scrollView.pagingEnabled = YES;

UITableView

self.tableView.separatorStyle = UITableViewCellSeparatorStyleNone; // 隐藏分割线

// 滚动到顶部

// 滑动到顶部
[tableView scrollRectToVisible:CGRectMake(0, 0, 1, 1) animated:YES];
[tableView setContentOffset:CGPointZero animated:NO];

// 滑动到指定项

// 获取所点目录对应的indexPath值
NSIndexPath *selectIndexPath = [NSIndexPath indexPathForRow:0 inSection:index];
    
// 让table滚动到对应的indexPath位置
[tableView scrollToRowAtIndexPath:selectIndexPath atScrollPosition:UITableViewScrollPositionBottom animated:YES];

// 隐藏多余的分割线

UIView *view = [UIView new];
view.backgroundColor = [UIColor clearColor];
[myTableView setTableFooterView:view];

// 这样更简单

[self.tableView setTableFooterView:[UIView new]];

// 获取指定项cell

UITableViewCell *cell = [tableView cellForRowAtIndexPath:indexPath];

UICollectionView

// 获取指定项

UICollectionViewCell *cell = [collectionViewClass cellForItemAtIndexPath:indexPath];

布局视图相关

一、navigationController

// 在 AppDelegate.m 文件中修改，达到全局改变效果

// 导航栏背景色
[[UINavigationBar appearance] setBarTintColor:MAIN_COLOR];
    
// 不启用半透明效果
[[UINavigationBar appearance] setTranslucent:NO];
    
// 导航按钮为白色
[[UINavigationBar appearance] setTintColor:[UIColor whiteColor]];
    
// 导航文本白色
[[UINavigationBar appearance] setTitleTextAttributes:@{NSForegroundColorAttributeName:[UIColor whiteColor]}];
    
// 修改状态栏颜色
// Info.plist 文件中 View controller-based status bar appearance 设置为NO
[[UIApplication sharedApplication] setStatusBarStyle:UIStatusBarStyleLightContent];
    
// 导航 back按钮不显示文本
[[UIBarButtonItem appearance] setBackButtonTitlePositionAdjustment:UIOffsetMake(0, -60)
                                                         forBarMetrics:UIBarMetricsDefault];
    

// 修改导航栏文本颜色，在UIViewController中修改

[self.navigationController.navigationBar setTitleTextAttributes:@{NSForegroundColorAttributeName:[UIColor whiteColor]}];

// 设置导航栏透明

- (void)viewWillAppear:(BOOL)animated { // 修改为透明
    [self.navigationController.navigationBar setBackgroundImage:[UIImage new] forBarMetrics:UIBarMetricsDefault];
    [self.navigationController.navigationBar setShadowImage:[UIImage new]];
    self.navigationController.navigationBar.translucent = YES;
    
    [super viewWillAppear:animated];
}

- (void)viewWillDisappear:(BOOL)animated { // 恢复默认主题
    [self.navigationController.navigationBar setBackgroundImage:nil forBarMetrics:UIBarMetricsDefault];
    [self.navigationController.navigationBar setShadowImage:nil];
    [self.navigationController.navigationBar setBarTintColor:MAIN_COLOR];
    
    [super viewWillDisappear:animated];
}

二、屏幕宽高

CGFloat screenWidth = [[UIScreen mainScreen] bounds].size.width;

三、导航栏、状态栏高度

// 状态栏高度
[[UIApplication sharedApplication] statusBarFrame].size.height
// 导航栏高度
self.navigationController.navigationBar.frame.size.height;

其它相关

一、获取版本号

// 获取版本号
NSDictionary *infoDic = [[NSBundle mainBundle] infoDictionary];
NSString *appVersion = [infoDic objectForKey:@"CFBundleShortVersionString"];

二、获取全部系统字体

NSArray *familyNames = [UIFont familyNames];
for( NSString *familyName in familyNames ){
 
    printf( "Family: %s \n", [familyName UTF8String] );
 
    NSArray *fontNames = [UIFont fontNamesForFamilyName:familyName];
    for( NSString *fontName in fontNames ){
 
        printf( "\tFont: %s \n", [fontName UTF8String] );
    }
}

三、判断代理有木有实现某方法

if (self.delegate || [self.delegate respondsToSelector:@selector(test:string)]) {
// YES;
}

SEL sel = @selector(rightButtonClick);
if ([_arrayTabView[index] respondsToSelector:sel]) {
    [_arrayTabView[index] performSelector:sel withObject:self]; //调用选择器方法
}

四、常用宏

// 宏 方法

// 屏幕的判定
#define IS_IPAD (UI_USER_INTERFACE_IDIOM() == UIUserInterfaceIdiomPad)
#define IS_IPHONE (UI_USER_INTERFACE_IDIOM() == UIUserInterfaceIdiomPhone)
#define IS_RETINA ([[UIScreen mainScreen] scale] >= 2.0)

// 屏幕宽高
#define SCREEN_WIDTH ([[UIScreen mainScreen] bounds].size.width)
#define SCREEN_HEIGHT ([[UIScreen mainScreen] bounds].size.height)
#define SCREEN_MAX_LENGTH (MAX(SCREEN_WIDTH, SCREEN_HEIGHT))
#define SCREEN_MIN_LENGTH (MIN(SCREEN_WIDTH, SCREEN_HEIGHT))

// 状态栏+导航栏高度
#define STATUS_NAV_HEIGHT [[UIApplication sharedApplication]statusBarFrame].size.height + self.navigationController.navigationBar.frame.size.height

// 手机型号
#define IS_IPHONE_4_OR_LESS (IS_IPHONE && SCREEN_MAX_LENGTH < 568.0)
#define IS_IPHONE_5 (IS_IPHONE && SCREEN_MAX_LENGTH == 568.0)
#define IS_IPHONE_6 (IS_IPHONE && SCREEN_MAX_LENGTH == 667.0)
#define IS_IPHONE_6P (IS_IPHONE && SCREEN_MAX_LENGTH >= 736.0)
//#define IS_IPHONE_6P (IS_IPHONE && SCREEN_MAX_LENGTH == 736.0)

// IOS版本
#define IS_IOS7 ([[[[UIDevice currentDevice] systemVersion] substringToIndex:1] intValue]==7)
#define IS_IOS8 ([[[[UIDevice currentDevice] systemVersion] substringToIndex:1] intValue]>=8)

//// 真机或模拟器
//#if TARGET_IPHONE_SIMULATOR//模拟器
//
//#elif TARGET_OS_IPHONE//真机
//
//#endif

// 颜色取值
#define RGBCOLOR(r,g,b) [UIColor colorWithRed:(r)/255.0f green:(g)/255.0f blue:(b)/255.0f alpha:1]

// 自定义Log
#ifdef DEBUG  //调试阶段
#define DEBUGLog(...)         NSLog(__VA_ARGS__)
#else         //发布阶段
#define   DEBUGLog(...)
#endif

五、打印特殊值

NSLog(@"rect %@", NSStringFromCGRect(self.view.frame));
NSLog(@"rect %@", NSStringFromCGRect(self.view.bounds));
NSLog(@"size %@", NSStringFromCGSize(self.view.frame.size));
NSLog(@"point %@", NSStringFromCGPoint(self.view.frame.origin));
//  其它类似

NSArray 

// 让数组中的每个对象执行指定方法

<pre name="code" class="objc">// 无参数
[mainView.subviews makeObjectsPerformSelector:@selector(removeFromSuperview)];
// 带个参数
[tabController.tabBar.items makeObjectsPerformSelector:@selector(setEnabled:) withObject:false];