控制器和应用数据存储
1、UINavigationController, 继承UIViewController，UINavigationController以栈的形式保存子控制器
1)把控制器添加到导航控制器栈里有两种方式：
导航控制器 UINavigationController *nav = [[UINavigationController alloc] init];
比如有一个控制器：UIViewController *control = [[UIViewController alloc] init];
第一种方式:[nav addChildViewController:control];
第二种方式:[nav pushViewController:control animated:YES];
2)从导航控制器栈里中移出栈顶的控制器：- (UIViewController *)popViewControllerAnimated:(BOOL)animated;
回到指定的子控制器：- (NSArray *)popToViewController:(UIViewController *)viewController ainimated:(BOOL)animated;
回到根控制器：- (NSArray *)popToRootViewController ainimated:(BOOL)animated;
3）UINavigationItem的属性：
//左上角的返回按钮
@property(nonatomic, retain) UIBarButtonItem *backBarButtonItem;
//中间的标题视图
@property(nonatomic, retain) UIView *titleView;
//中间的标题文字
@property(nonatomic, copy) NSString *title;
//左上角的视图
@property(nonatomic, retain) UIBarButtonItem *leftBarButtonItem;
//右上角的视图
@property(nonatomic, retain) UIBarButtonItem *rightButtonItem;2、UIStoryboardSegue : 每个Segue有三个属性：
//唯一标识
@property(nonatomic, readonly) NSString *identifier;
//来源控制器
@property(nonatomic, readonly) id sourceViewController;
//目标控制器
@property(nonatomic, readonly) id destinationViewController;执行segue的时候，跳转之前会调用一个方法：- (void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender;
一般可以在这个方法做一些准备操作，例如给下一个控制器传值
3、ios应用常用的数据的存储方式主要有：
1）、plist (利用xml属性列表归档NSDictionary、NSArray、NSData、NSNumber等系统类型数据）
2）、NSUserDefaults 偏好设置
3）、NSKeydeArchiver归档（一般用来存储自定义对象）
4）、SQLite(关系型数据库，不能直接存储对象，使用sql语句序列化对象存储)
5）、Core Data (对象型数据库，吧内部环境屏蔽）
4、应用程序沙盒（模拟器沙盒大概路径：/Users/tan/Library/Developer/CoreSimulator/Devices/......）
每个应用程序都有自己的应用沙盒，用来和其他程序隔离；
沙盒的文件系统目录有三个：Documents、Library(又包含Caches和Preferences)、tmp；
1）、应用程序包包含了所有的资源文件和可执行文件；
2）、Documents保存应用运行时生成的需要持久化的数据，iTunes同步设备时会备份该目录；
3）、tmp保存应用运行时所需的临时数据，使用完毕后再将相应的文件从该目录删除。应用没有运行时，系统也可能会清除该目录下的文件。iTunes同步设备时，不会备份该目录；
4）、Library/Caches 保存应用运行时生成的非重要的需要持久化的数据，iTunes同步设备时不会备份该目录；
5）、Library/Prefences保存应用的所有偏好设置，iTunes同步设备时会备份该目录
测试获取应用程序沙盒下和真机下Documents路径和安装包资源文件路径方法：
//沙盒Documents路径 ： NSSearchPathForDirectoriesInDomains函数第三个参数布尔类型expandTilde表示是否显示全路径
NSString *path1 = [NSHomeDirectory() stringByAppendingPathComponent:@"Documents"];
NSString *path2 = [NSHomeDirectoryForUser(nil) stringByAppendingPathComponent:@"Documents"];
NSString *path3 = [NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES) lastObject];
NSString *path4 = [NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, NO) lastObject];
NSLog(@"path1 = %@", path1);
NSLog(@"path2 = %@", path2);
NSLog(@"path3 = %@", path3);
NSLog(@"path4 = %@", path4);
//安装包资源文件路径
NSString *indexUrl = [[NSBundle mainBundle] pathForResource:@"index" ofType:@"html"];
NSLog(@"indexUrl: %@", indexUrl);
/*
模拟器测试打印日志：
path1 = /Users/PX/Library/Developer/CoreSimulator/Devices/57E9C8A1-2AB2-48C9-9304-254BF841DC2D/data/Containers/Data/Application/948A9B33-FEB7-479B-90FB-F27D573663DF/Documents
path2 = /Users/PX/Library/Developer/CoreSimulator/Devices/57E9C8A1-2AB2-48C9-9304-254BF841DC2D/data/Containers/Data/Application/948A9B33-FEB7-479B-90FB-F27D573663DF/Documents
path3 = /Users/PX/Library/Developer/CoreSimulator/Devices/57E9C8A1-2AB2-48C9-9304-254BF841DC2D/data/Containers/Data/Application/948A9B33-FEB7-479B-90FB-F27D573663DF/Documents
path4 = ~/Documents
indexUrl: /Users/PX/Library/Developer/CoreSimulator/Devices/57E9C8A1-2AB2-48C9-9304-254BF841DC2D/data/Containers/Bundle/Application/67C8E4C2-3DF1-4673-8FE9-48397EDA7759/tan_IOSFuXi.app/index.html
真机测试打印日志：
path1 = /var/mobile/Containers/Data/Application/CC29D2BC-F10B-41F4-A1CD-239E379604F6/Documents
path2 = /var/mobile/Containers/Data/Application/CC29D2BC-F10B-41F4-A1CD-239E379604F6/Documents
path3 = /var/mobile/Containers/Data/Application/CC29D2BC-F10B-41F4-A1CD-239E379604F6/Documents
path4 = ~/Documents
indexUrl: /var/mobile/Containers/Bundle/Application/2B0645D3-0B3F-46BF-841C-202B5A5A0C4B/tan_IOSFuXi.app/index.html
*/5、应用程序数据存储方式示例代码：
//定义两个属性
@property (weak, nonatomic) IBOutlet UITextField *txtPlist; //输入信息
@property (weak, nonatomic) IBOutlet UILabel *lblPlist; //展示信息1）、使用plist文件来存储系统类数据
//将字典数据存入*.plist文件中
- (IBAction)savePlist:(id)sender{
//沙盒Documents文件夹路径 最后那个参数expandTilde代表是否展开完整路径
NSString *path = [[NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES) lastObject] stringByAppendingPathComponent:@"tan.plist"];
NSDictionary *dic = @{@"msg": self.txtPlist.text};
//原子的写入文件中
if ([dic writeToFile:path atomically:YES]){
self.txtPlist.text = @"保存成功";
}
else{
self.txtPlist.text = @"保存失败";
}
}
//* 读取数据plist文件数据 */
- (IBAction)readPlist:(id)sender{
NSString *path = [[NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES) lastObject] stringByAppendingPathComponent:@"tan.plist"];
NSDictionary *dic = [NSDictionary dictionaryWithContentsOfFile:path];
self.lblPlist.text = [NSString stringWithFormat:@"%@: %@", [[dic allKeys] firstObject], [[dic allValues] lastObject]];
}
2）、使用偏好设置存储
/* 保存数据到用户偏好设置中 */
- (IBAction)saveDataToUserPreference:(id)sender{
NSUserDefaults *ud = [NSUserDefaults standardUserDefaults];
// 自动帮我们生成一个plist文件存放在偏好设置的文件夹
[ud setObject:self.txtPlist.text forKey:@"msg"];
// 同步：把内存中的数据和沙盒同步
[ud synchronize];
self.txtPlist.text = @"存储到偏好设置OK";
}
/* 从用户偏好设置中读取数据 */
- (IBAction)readDataByUserPreference:(id)sender{
NSUserDefaults *ud = [NSUserDefaults standardUserDefaults];
self.lblPlist.text = [ud objectForKey:@"msg"];
}
3)、使用NSKeyedArchiver对自定义对象进行归档， 使用NSKeyedUnarchiver解析归档对象
首先自定义类需要实现NSCoding协议，然后实现方法
- (void)encodeWithCoder:(NSCoder *)aCoder; //定义自定义类哪些属性需要归档，如何归档
- (id)initWithCoder:(NSCoder *)aDecoder; // 定义归档对象解析时哪些属性需要解析，如何解析
如果父类也遵守了NSCoding协议，应该在encodeWithCoder:方法中加上一句：[super encodeWithCode:encode];
确保继承的实例变量也能被编码，即也能被归档
应该在initWithCoder:方法中加上一句：self = [super initWithCoder:decoder];
确保继承的实例变量也能被解码，即也能被恢复
#import <Foundation/Foundation.h>
@interface TanPerson : NSObject <NSCoding>
@property (nonatomic, copy) NSString *name;
@property (nonatomic, assign) int age;
@property (nonatomic, copy) NSString *email;
@property (nonatomic, copy) NSString *address;
+ (instancetype)tanPersonWithDict:(NSDictionary *)dict;
- (instancetype)initWithDict:(NSDictionary *)dict;
@end#import "TanPerson.h"
@implementation TanPerson
+ (instancetype)tanPersonWithDict:(NSDictionary *)dict{
return [[self alloc] initWithDict:dict];
}
- (instancetype)initWithDict:(NSDictionary *)dict{
if (self = [super init]){
[self setValuesForKeysWithDictionary:dict];
}
return self;
}
/**
对象归档时调用
哪些属性需要归档，又如何归档
*/
- (void)encodeWithCoder:(NSCoder *)aCoder{
[aCoder encodeObject:_address forKey:@"tan_address"];
[aCoder encodeInt:_age forKey:@"age"];
[aCoder encodeObject:_name forKey:@"tan_name"];
}
/**
解析对象时调用
哪些属性需要解析，如何解析
*/
- (id)initWithCoder:(NSCoder *)aDecoder{
if (self = [super init]){
_address = [aDecoder decodeObjectForKey:@"tan_address"];
_age = [aDecoder decodeIntForKey:@"age"];
_name = [aDecoder decodeObjectForKey:@"tan_name"];
}
return self;
}
@end//控制器内方法
/* NSKeyedArchiver归档 用来存储自定义对象 */
- (IBAction)saveDataToArchiver:(id)sender{
TanPerson *person = [[TanPerson alloc] init];
person.age = 25;
person.address = self.txtPlist.text;
person.name = @"呼呼";
NSString *path = [[NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES) lastObject] stringByAppendingPathComponent:@"tanPerson.data"];
if ([NSKeyedArchiver archiveRootObject:person toFile:path]){
self.txtPlist.text = @"对象归档OK了";
}
else{
self.txtPlist.text = @"对象归档行动失败！";
}
}
/* 使用NSKeyedUnarchiver解析归档对象 */
- (IBAction)readyDataByArchiver:(id)sender{
NSString *path = [[NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES) lastObject] stringByAppendingPathComponent:@"tanPerson.data"];
TanPerson *person = [NSKeyedUnarchiver unarchiveObjectWithFile:path];
self.lblPlist.text = [NSString stringWithFormat:@"name: %@, age: %d, address: %@", person.name, person.age, person.address];
}
4）使用NSKeyedArchiver归档多个对象和解析
/* 使用NSKeyedArchiver归档多个对象 */
- (IBAction)saveMulObjectByArchive:(id)sender{
TanPerson *person1 = [[TanPerson alloc] init];
person1.name = @"小毛";
TanPerson *person2 = [[TanPerson alloc] init];
person2.name = @"小亲";
NSString *path = [[NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES) lastObject] stringByAppendingPathComponent:@"tanMulPerson.data"];
//NSData可以为一些数据提供临时存储空间，以便随后写入文件，或者存放从磁盘读取的文件内容
NSMutableData *data = [NSMutableData data]; //新建一块可变数据区
//将数据区连接到一个NSKeyedArchiver对象
NSKeyedArchiver *archiver = [[NSKeyedArchiver alloc] initForWritingWithMutableData:data];
//开始存档对象，存档的数据都会存储到data中
[archiver encodeObject:person1 forKey:@"perOne"];
[archiver encodeObject:person2 forKey:@"perTwo"];
//存档完毕 必须调用
[archiver finishEncoding];
//将存档的数据存入文件
[data writeToFile:path atomically:YES];
self.txtPlist.text = @"多个对象存档完成了";
}
/* 使用NSKeyedUnArchiver解析多个归档对象 */
- (IBAction)readMulObjectByArchiver:(id)sender{
NSString *path = [[NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES) lastObject] stringByAppendingPathComponent:@"tanMulPerson.data"];
//将数据读取到data上
NSMutableData *data = [NSMutableData dataWithContentsOfFile:path];
//解析数据
NSKeyedUnarchiver *unArchiver = [[NSKeyedUnarchiver alloc] initForReadingWithData:data];
TanPerson *person1 = [unArchiver decodeObjectForKey:@"perOne"];
TanPerson *person2 = [unArchiver decodeObjectForKey:@"perTwo"];
[unArchiver finishDecoding]; //恢复完毕 可以不调用
self.lblPlist.text = [NSString stringWithFormat:@"name1: %@, name2: %@", person1.name, person2.name];
}腾讯云开发者
