gewill

极客班 iOS 应用开发实战（六）

本文目录

段老师的视频教程，采用都是比较通用是 Demo，方便以后代码复用。也是从项目实践经验来教授相关知识如 FMDB，这几节课获益匪浅。

Demo 源码见 Github，并添加了相关注释。

28. 沙盒机制

介绍几种数据持久化的方案，选择合适项目的方案：

  • 沙盒机制
  • NSFileManager
  • Plist、Archive数据归档 * SQLite3应用
  • NSUserDefaults

沙盒目录结构 NSDocumentDirectory：

  • Application Bundle/
  • Documents/
  • Library/Caches/
  • Library/Perferences/
  • tmp/

29. NSFileManager & Plist

存取文档的方法封装一个通用的类BLUtility.h/m，方便调用。以下代码是测试保存文本文档。

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//
//  BLUtility.m

/**
 *  创建目录
 *
 *  @param dirPath 待创建的目录
 *  @param isDir   结尾是否是目录
 *
 *  @return 是否创建成功
 */
+ (NSString*) getPathWithinDocumentDir:(NSString*)aPath {
	NSString *fullPath = nil;
	NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
	
	if ([paths count] > 0) {
		fullPath = (NSString *)[paths objectAtIndex:0];
		if ([aPath length] > 0) {
			fullPath = [fullPath stringByAppendingPathComponent:aPath];
		}
	}
	return fullPath;
}

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//
//  BLArchiveViewController.m

/**
 *  测试保存文档和 plist 的按钮关联的 Action 方法
 *
 *  @param sender <#sender description#>
 */
- (void)writeFileButtonClicked:(id)sender {
    // 1 - 测试字符串文档，保存到 Documents
    // 1.1 - 生成并保存
    NSString *string = @"ABC副经理";
    NSString *stringFilePath = [BLUtility getPathWithinDocumentDir:@"string.text"];
    [BLUtility createDirectory:stringFilePath lastComponentIsDirectory:NO];
    [string writeToFile:stringFilePath atomically:YES encoding:NSUTF8StringEncoding error:nil];
}

30. Archive 数据归档和 NSUserDefaults

转化为 NSData，二进制的数据，利于存储和传输。

遵循 NSCoding 协议，即可实现编码和解码的类，进一步对其归档和解档。也用到了封装的类BLUtility.h/m。本例中文档保存到 NSUserDefaults：

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//
//  BLUser.m

/**
 *  解码
 *
 *  @param aDecoder 编码类型
 *
 *  @return 解码得到的对象
 */
- (id)initWithCoder:(NSCoder *)aDecoder {
	self = [super init];
	if (self) {
		self.userName	= [aDecoder decodeObjectForKey:@"userName"];
		self.email		= [aDecoder decodeObjectForKey:@"email"];
		self.password	= [aDecoder decodeObjectForKey:@"password"];
		self.age		= [aDecoder decodeIntForKey:@"age"];
	}
	return self;
}
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//
//  BLUtility.m

/**
 *  解档
 *
 *  @param archivedData 待解档的 NSData
 *  @param key           key
 *
 *  @return  解档完成的对象
 */
+ (NSObject *) unarchiverObject:(NSData *)archivedData withKey:(NSString *)key {
	if(archivedData == nil) {
		return nil;
	}
	
	NSKeyedUnarchiver *unarchiver = [[NSKeyedUnarchiver alloc] initForReadingWithData:archivedData];
	NSObject *object = [unarchiver decodeObjectForKey:key];
	[unarchiver finishDecoding];
	return object;
}
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//
//  BLArchiveViewController.m

/**
 *  读取按钮关联的 Action 方法
 *
 *  @param sender <#sender description#>
 */
- (void) readButtonClicked:(id)sender {
    NSUserDefaults *userDefaults = [NSUserDefaults standardUserDefaults];
    NSInteger test = [userDefaults integerForKey:@"integer"];
    NSLog(@"test = %li", test);
    
	NSString *userDataPath = [BLUtility getPathWithinDocumentDir:UserDataName];
	if ([userDataPath length] > 0 && [[NSFileManager defaultManager] fileExistsAtPath:userDataPath]) {
        NSData *userData = [NSData dataWithContentsOfFile:userDataPath];
		BLUser *user = (BLUser *)[BLUtility unarchiverObject:userData withKey:@"UserData"];
		_userNameTextField.text = user.userName;
		_emailTextField.text = user.email;
		_passwordTextField.text = user.password;
		_ageTextField.text = [NSString stringWithFormat:@"%ld", user.age];
	}
}

###延伸阅读：

31. SQLite3

通过 FMDB 封装，得以 OBjective-C 访问 SQLite，完成常用增删改查。从语法和数据体积实现轻量级存储方案。这个方案稍后用在习题“同学录”上实践一下。

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//
//  BLPoemDB.h


#import <Foundation/Foundation.h>
#import "FMDatabase.h"
#import "BLPoem.h"

@interface BLPoemDB : NSObject {
    /**
     *  创建一个 FMDatabase 实例
     */
	FMDatabase		*_db;
}

/**
 *  创建一个表
 *
 *  @return 是否创建成功
 */
- (BOOL) createPoemTable;

/**
 *  增加一首诗到表
 *
 *  @param poem 待添加的诗
 *
 *  @return 是否添加成功
 */
- (BOOL) addPoem:(BLPoem *)poem;

/**
 *  查询所有诗
 *
 *  @return 查询到的包含所有诗的数组
 */
- (NSMutableArray *) getAllPoems;

/**
 *  查询被收藏的诗
 *
 *  @return 查询到的包含所有收藏的诗的数组
 */
- (NSMutableArray *) getFavoritesPoems;

/**
 *  更改是非收藏这一首诗
 *
 *  @param favorite 是否收藏
 *  @param poemId   待更改的诗的 ID
 *
 *  @return 是否更改收藏成功
 */
- (BOOL) setFavorite:(BOOL)favorite favoriteId:(NSInteger)poemId;

/**
 *  删除指定 ID 的一首诗
 *
 *  @param poemId 待删除的诗的 ID
 *
 *  @return  是否删除成功
 */
- (BOOL) deletePoemWithPoemId:(NSInteger)poemId;

@end
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//
//  BLPoemDB.m
//  BLDataSaveDemo


#import "BLPoemDB.h"
#import "BLUtility.h"

#define BLPOEMDBNAME @"BLPoemDB.sqlite"

@implementation BLPoemDB

/**
 *  初始化数据库 FMDatabase 实例
 *
 *  @return 初始化得到的 FMDatabase 实例
 */
-(id) init {
	self = [super init];
	if (self) {
		NSString *dbPath = [BLUtility getPathWithinDocumentDir:BLPOEMDBNAME];
		NSFileManager *fileManager = [NSFileManager defaultManager];
		BOOL existFile = [fileManager fileExistsAtPath:dbPath];
		if (existFile == NO) {
			NSString *poemDBPath = [[[NSBundle mainBundle] resourcePath] stringByAppendingPathComponent:BLPOEMDBNAME];
			[fileManager copyItemAtPath:poemDBPath toPath:dbPath error:nil];
		}
		_db	 = [[FMDatabase alloc] initWithPath:dbPath];
		if ([_db open] == NO) {
			return nil;
		}
	}
	return self;
}


- (BOOL) createPoemTable {
	[_db beginTransaction];
	BOOL success = [_db executeUpdate:@"CREATE TABLE IF NOT EXISTS POEMTABLE ("
					@"ID INTEGER PRIMARY KEY NOT NULL,"
					@"POEMNAME TEXT NOT NULL,"
					@"POETNAME TEXT NOT NULL,"
					@"POEMCONTENT TEXT NOT NULL,"
					@"WHETHERFAVORITE BOOL NOT NULL);"];
	[_db commit];
	
	if(!success || [_db hadError]) {
		[_db rollback];
		return NO;
	}
	return YES;
}

- (BOOL) addPoem:(BLPoem *)poem {
	FMResultSet *rs = [_db executeQuery:@"SELECT ID FROM POEMTABLE WHERE ID=?", [NSNumber numberWithInteger:poem.poemId]];
	if(rs && [rs next]) {
		[rs close];
		return YES;
	}
	[rs close];
	
	[_db beginTransaction];
	NSString *bookMark = nil;		
	BOOL success =  [_db executeUpdate:@"INSERT OR IGNORE INTO POEMTABLE (ID,POEMNAME,POETNAME,POEMCONTENT,WHETHERFAVORITE) VALUES (?,?,?,?,?);",
					 [NSNumber numberWithInteger:poem.poemId],
					 poem.poemName,
					 poem.poetName,
					 poem.poemContent,
					 [NSNumber numberWithBool:poem.whetherFavorite],
					 bookMark];
	[_db commit];
	
	if(!success || [_db hadError]) {
		[_db rollback];
		return NO;
	}
	return YES;
}

- (NSMutableArray *) getAllPoems {	
	NSMutableArray *result = [[NSMutableArray alloc] init];
//	FMResultSet *rs = [_db executeQuery:@"SELECT * FROM POEMTABLE WHERE ID=? AND WHETHERFAVORITE=?", [NSNumber numberWithInt:poem.poemId], [NSNumber numberWithBool:poem.whetherFavorite]];
	FMResultSet *rs = [_db executeQuery:@"SELECT * FROM POEMTABLE"];
	while([rs next]) {
		BLPoem *poem = [[BLPoem alloc] init];
		poem.poemId = [rs intForColumn:@"ID"];
		poem.poemName = [rs	stringForColumn:@"POEMNAME"];
		poem.poetName = [rs stringForColumn:@"POETNAME"];
		poem.poemContent = [rs stringForColumn:@"POEMCONTENT"];
		poem.whetherFavorite = [rs boolForColumn:@"WHETHERFAVORITE"];
		[result addObject:poem];
	}
	[rs close];
	return result;
}

- (NSMutableArray *) getFavoritesPoems {
	NSMutableArray *result = [[NSMutableArray alloc] init];	
	FMResultSet *rs = [_db executeQuery:@"SELECT * FROM POEMTABLE WHERE WHETHERFAVORITE=?", [NSNumber numberWithBool:YES]];
	while([rs next]) {
		BLPoem *poem = [[BLPoem alloc] init];
		poem.poemId = [rs intForColumn:@"ID"];
		poem.poemName = [rs	stringForColumn:@"POEMNAME"];
		poem.poetName = [rs stringForColumn:@"POETNAME"];
		poem.poemContent = [rs stringForColumn:@"POEMCONTENT"];
		poem.whetherFavorite = [rs boolForColumn:@"WHETHERFAVORITE"];
		[result addObject:poem];
	}
	[rs close];
	return result;
}

- (BOOL) setFavorite:(BOOL)favorite favoriteId:(NSInteger)poemId {
	if (_db == nil) {
		return NO;
	}
	[_db beginTransaction];
	BOOL result = [_db executeUpdate:@"UPDATE POEMTABLE SET WHETHERFAVORITE=? WHERE ID=?", [NSNumber numberWithBool:favorite], [NSNumber numberWithInteger:poemId]];
	[_db commit];
	return result;
}

- (BOOL) deletePoemWithPoemId:(NSInteger)poemId {
	[_db beginTransaction];
	BOOL success = [_db executeUpdate:@"DELETE FROM POEMTABLE WHERE ID=?", [NSNumber numberWithInteger:poemId]];
	[_db commit];
	if(!success || [_db hadError]) {
		[_db rollback];
		return NO;
	}
	return YES;
}

- (void) dealloc {
	[_db	close];
	_db		= nil;
}

@end

延伸阅读：

32. 多线程和多媒体

简单介绍了常见多媒体的播放：

  • UIImagePickerViewController
  • UIActionSheet （👈名字谐音）
  • AVAudioPlayer
  • SystenSounID
  • MPMoviePlayerViewController
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#import <AVFoundation/AVFoundation.h>
#import <AudioToolbox/AudioToolbox.h>
#import <MediaPlayer/MediaPlayer.h>

@interface BLOneViewController ()<UIAlertViewDelegate, UIActionSheetDelegate, UIImagePickerControllerDelegate, UINavigationControllerDelegate> {
    AVAudioPlayer           *audioPlayer;
    SystemSoundID           systemSoundId;
}


#pragma mark - Play Music button action

- (IBAction)palyMusic:(UIButton *)sender {
    

    
    if (!audioPlayer) {
        NSString *mp3Path = [[NSBundle mainBundle] pathForResource:@"yishengsuoai" ofType:@"mp3"];
        NSURL *mp3Url = [[NSURL alloc] initFileURLWithPath:mp3Path];
        audioPlayer = [[AVAudioPlayer alloc] initWithContentsOfURL:mp3Url error:NULL];
        audioPlayer.numberOfLoops = -1;
        [audioPlayer prepareToPlay];
    }
    if ([audioPlayer isPlaying]) {
        [audioPlayer stop];
        sender.titleLabel.text = @"Play Music";
        
    }else {
        [audioPlayer play];
        sender.titleLabel.text = @"Pasue Music";
        
    }
}

33. 硬件访问、CALayer & Core Graphics

33.1. gravity and user acceleration

Useage: shaking device to feedback or 360° image

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// 4 - Start update divice motion and print them
   // The accelerometer measures the sum of two acceleration vectors: gravity and user acceleration.
   NSOperationQueue *diviceMotionQueue = [[NSOperationQueue alloc] init];
   [self.motionManager startDeviceMotionUpdatesToQueue:diviceMotionQueue
                                           withHandler:^(CMDeviceMotion *motion, NSError *error) {
                                               
                                               NSLog(@"\n \n-------------------------------------------------------------------------->\n \n 1 - attitude: %@ \n 2 - rotation rate x: %f, y: %f, z: %f,\n  \n 3 - gravity x: %f, y: %f, z: %f \n \n 4 - user acceleration x: %f, y: %f, z: %f \n \n 5 - magnetic field accuracy: %d, x: %f, y: %f, z: %f \n \n <--------------------------------------------------------------------------\n \n" ,
                                                     motion.attitude,
                                                     motion.rotationRate.x, motion.rotationRate.y, motion.rotationRate.z,
                                                     motion.gravity.x, motion.gravity.y, motion.gravity.z,
                                                     motion.userAcceleration.x, motion.userAcceleration.y, motion.userAcceleration.z,
                                                     motion.magneticField.accuracy, motion.magneticField.field.x, motion.magneticField.field.y, motion.magneticField.field.z);
                                           }];

Search the definiton of each new word, really 😄😄😄.

Do you believe that, At least I don’t think so.

Output:

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-------------------------------------------------------------------------->
 
 1 - attitude: CMAttitude Pitch: 0.751292, Roll: 0.555726, Yaw: 22.198534
 
 2 - rotation rate x: 0.001511, y: -0.000795, z: 0.002454,
  
 3 - gravity x: 0.009698, y: -0.013112, z: -0.999867 
 
 4 - user acceleration x: -0.002603, y: 0.000783, z: -0.014095 
 
 5 - magnetic field accuracy: -1, x: 0.000000, y: 0.000000, z: 0.000000 
 
 <--------------------------------------------------------------------------

33.2. CALayer

Modifying the Layer’s Appearance Properties.
Lots of properties really similar to Sketch.

33.3. Core Graphics

CGContextRef: An opaque type that represents a Quartz 2D drawing environment.

Path on CGContextRef vs Vector on Artboard in Sketch, by learn Sketch really make sense of those abstract concepts.

34. 自定义手势、Block & GCD

34.1. 手势

尽量设计使用常用的手势

设计一个小 Demo，实现：Shake Your iPhone To Send Feedback Email To Me😄

34.2. Block

比较简洁的函数，就在当前就可以调用。

34.3. GCD

Group queue：并行执行多任务比较牛。

35. APNS、Core Date、URL Scheme、单元测试、APP发布流

35.1. APNS

Remote Notification

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// 1 - Register Remote Notification
// 2 - Register deviceToken
// 3 - Receive Remote Notification
// 4 - Update Icon Badge Number

稍后添加到 Classmates

35.2. Core Data

核心概念：

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// 程序员和管理对象模式之间的桥梁，做数据库的增删改查等操作
@property (readonly, strong, nonatomic) NSManagedObjectContext *managedObjectContext;

// 数据库里的不同管理对象类型
@property (readonly, strong, nonatomic) NSManagedObjectModel *managedObjectModel;

// 数据库文件和程序之间的联系桥梁
@property (readonly, strong, nonatomic) NSPersistentStoreCoordinator *persistentStoreCoordinator;

稍后把 Classmate 整个 Core Data 的版本

35.3. URL Scheme

就是一个通过个地址访问系统软件或第三方软件，如地图和 Launch Center Pro。iOS 9之后估计有更多可能性。

35.4. 单元测试或断点测试

35.5. App 发布流程