iOS8 新特性

iOS8新特性主要体现在4方面

1.UIAlertController 对alert&actionSheet的封装

UIAlertController.h

提示框按钮的选择

typedef NS_ENUM(NSInteger, UIAlertActionStyle) {

    UIAlertActionStyleDefault = 0,

    UIAlertActionStyleCancel,

    UIAlertActionStyleDestructive

} NS_ENUM_AVAILABLE_IOS(8_0);

提示框的样式

typedef NS_ENUM(NSInteger, UIAlertControllerStyle) {

    UIAlertControllerStyleActionSheet = 0,

    UIAlertControllerStyleAlert

} NS_ENUM_AVAILABLE_IOS(8_0);

NS_CLASS_AVAILABLE_IOS(8_0) @interface UIAlertAction : NSObject <NSCopying>

创建提示框按钮 

+ (instancetype)actionWithTitle:(NSString *)title style:(UIAlertActionStyle)style handler:(void (^)(UIAlertAction *action))handler;

@property (nonatomic, readonly) NSString *title;

@property (nonatomic, readonly) UIAlertActionStyle style;

@property (nonatomic, getter=isEnabled) BOOL enabled;

@end

NS_CLASS_AVAILABLE_IOS(8_0) @interface UIAlertController : UIViewController

创建提示框 

+ (instancetype)alertControllerWithTitle:(NSString *)title message:(NSString *)message preferredStyle:(UIAlertControllerStyle)preferredStyle;

 添加按钮

- (void)addAction:(UIAlertAction *)action;

@property (nonatomic, readonly) NSArray *actions;

添加文本输入框

- (void)addTextFieldWithConfigurationHandler:(void (^)(UITextField *textField))configurationHandler;

@property (nonatomic, readonly) NSArray *textFields;

@property (nonatomic, copy) NSString *title;

@property (nonatomic, copy) NSString *message;

@property (nonatomic, readonly) UIAlertControllerStyle preferredStyle;

 简单实用示例

//    1.创建提示框对象，默认是actionSheet效果

    UIAlertController *alert = [UIAlertController alertControllerWithTitle:@"注意" message:@"我的呈现方式变了" preferredStyle:UIAlertControllerStyleAlert];

//    2.创建取消按钮并添加到提示框上

    [alert addAction:[UIAlertAction actionWithTitle:@"取消" style:UIAlertActionStyleCancel handler:^(UIAlertAction *action) {

        NSLog(@"取消按钮被点击了");

    }]];

//    3.呈现提示框

    [self presentViewController:alert animated:YES completion:nil];

2.UIPopoverController的呈现方式改变不必再像之前那样，直接通过present方式呈现

UIViewController.h

typedef NS_ENUM(NSInteger, UIModalPresentationStyle) {

        UIModalPresentationFullScreen = 0,

        UIModalPresentationPageSheet NS_ENUM_AVAILABLE_IOS(3_2),

        UIModalPresentationFormSheet NS_ENUM_AVAILABLE_IOS(3_2),

        UIModalPresentationCurrentContext NS_ENUM_AVAILABLE_IOS(3_2),

        UIModalPresentationCustom NS_ENUM_AVAILABLE_IOS(7_0),

        UIModalPresentationOverFullScreen NS_ENUM_AVAILABLE_IOS(8_0),

        UIModalPresentationOverCurrentContext NS_ENUM_AVAILABLE_IOS(8_0),

        UIModalPresentationPopover NS_ENUM_AVAILABLE_IOS(8_0),

        UIModalPresentationNone NS_ENUM_AVAILABLE_IOS(7_0) = -1,         

};

@property (nonatomic,readonly) UIPopoverPresentationController *popoverPresentationController NS_AVAILABLE_IOS(8_0);

使用示例

//   1.创建内容控制器

    UITableViewController *contentVc = [[UITableViewController alloc] init];

//   2.1 设置呈现方式

    contentVc.modalPresentationStyle = UIModalPresentationPopover;

//   2.2设置在导航栏的左边按钮呈现

    contentVc.popoverPresentationController.barButtonItem = self.navigationItem.leftBarButtonItem;

//    3.呈现

    [self presentViewController:contentVc animated:YES completion:nil];

以前的方式

 // 1.创建内容控制器

    UITableViewController *contentVc = [[UITableViewController alloc] init];

      // 2.创建popover

    UIPopoverController *popover = [[UIPopoverController alloc] initWithContentViewController:contentVc];

    popover.popoverContentSize = CGSizeMake(100, 100);

       // 3.呈现

    [popover presentPopoverFromBarButtonItem:self.navigationItem.leftBarButtonItem permittedArrowDirections:UIPopoverArrowDirectionAny animated:YES];

3.获取用户授权的用户隐私保护

地图定位示例：

//导入定位框架

#import <CoreLocation/CoreLocation.h>

@interface ViewController ()<CLLocationManagerDelegate>

//设置定位对象

@property(nonatomic,strong)CLLocationManager* maneger;

@end

@implementation ViewController

- (void)viewDidLoad {

    [super viewDidLoad];

    //    当使用iOS8定位的时候需要请求用户授权，且在info.plist里添加字段NSLocationAlwaysUsageDescription 请求用户授权的描述

    //    iOS7仅仅需要在info.plist里添加字段Privacy - Location Usage Description 请求用户授权的描述

    //    不需要再写下面的代码

    if (IOS8) {

        [self.maneger requestAlwaysAuthorization];//请求用户授权

}

        //    开启定位

    [self.maneger startUpdatingLocation];

 }

4.针对屏幕适配应运而生的size classes

 size classes是为了解决storyboard只能订制一种屏幕样式的问题，它不再是具体的尺寸，而是抽象尺寸

通过宽/高 的compact any regular 组成了九种组合包含了所有苹果设备的尺寸

详情 ：http://www.cnblogs.com/lijianyi/p/4288462.html