iOS歸檔與解歸檔,持久化存儲 – iPhone手機開發技術文章 iPhone軟體開發教學課程

點此下載iOS歸檔,持久化存儲,解歸檔詳細工程

//數據持久化的本質:將數據讀取成文件保存在本地. 沙盒機制就是系統針對於每一個程序在本地生成的文件夾(名字隨機生成), 對於不同的應用程序, 不能訪問其他應用程序沙盒內的內容, 對於該應用程序內容起到保護作用:1 Documents:用來存儲長久保存的數據 2 xxx.app:應用程序的包, 包含應用程序加載所需的所有資源(readonly隻讀, 不可修改), 平時使用的NSBundle就是該包 3 Library: 1) Caches:本地緩存, 存儲想暫時保存的數據(Videos, Musics, Images) 比如:下載的視頻, 音頻, 圖片都存儲在該文件夾下 2) Preferences:存儲用戶的偏好設置, 比如程序是否是第一次啟動 4 tmp:存儲還未下載完的視頻, 音頻, 當下載完後, 將文件轉移到Caches文件夾下

#import "WYLReadAndWriteViewController.h"
#import "WYLArchive.h"
@interface WYLReadAndWriteViewController ()

@end

@implementation WYLReadAndWriteViewController

- (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil
{
    self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil];
    if (self) {
        // Custom initialization
    }
    return self;
}

- (void)viewDidLoad
{
    [super viewDidLoad];
    // Do any additional setup after loading the view.
    self.view.backgroundColor = [UIColor whiteColor];
    self.navigationItem.title = @"文件讀寫";
    UITextField *textField = [[UITextField alloc]initWithFrame:CGRectMake(40, 84, 220, 40)];
    textField.tag = 100;
    textField.placeholder  = @"請輸入內容";
    textField.delegate = self;
    textField.borderStyle = UITextBorderStyleRoundedRect;
    [self.view addSubview:textField];
    [textField release];
    UITextField *textField2 = [[UITextField alloc]initWithFrame:CGRectMake(40, 174, 220, 40)];
    textField2.tag = 101;
    textField2.placeholder  = @"顯示上一個輸入框的內容";
    textField2.delegate = self;
    textField2.borderStyle = UITextBorderStyleRoundedRect;
    [self.view addSubview:textField2];
    [textField2 release];
    UIButton *writeButton = [UIButton buttonWithType:UIButtonTypeSystem];
     writeButton.frame =  CGRectMake(45, 260, 60, 30);
    [writeButton setTitle:@"寫入" forState:UIControlStateNormal];
    [writeButton addTarget:self action:@selector(write:) forControlEvents:UIControlEventTouchUpInside];
    [self.view addSubview:writeButton];
    UIButton *readButton = [UIButton buttonWithType:UIButtonTypeSystem];
    readButton.frame = CGRectMake(190, 260, 60, 30);
    [readButton setTitle:@"讀取" forState:UIControlStateNormal];
    [readButton addTarget:self action:@selector(read:) forControlEvents:UIControlEventTouchUpInside];
    [self.view addSubview:readButton];
    UIButton *push = [UIButton buttonWithType:UIButtonTypeSystem];
    push.frame = CGRectMake(120, 310, 60, 30);
    [push setTitle:@"push" forState:UIControlStateNormal];
    [push addTarget:self action:@selector(push:) forControlEvents:UIControlEventTouchUpInside];
    [self.view addSubview:push];
    
    
}

- (NSString *)getFilePath
{
    //用來獲取指定文件夾的路徑::指定的文件夾;:設置查找的域, 我們自己的文件都是存儲在永華域的;:是否使用詳細路徑(絕對路徑) 因為最初該方法是使用與MAC OS下的, 而對於電腦系統來說, 可能會存儲多個用戶, 所以獲取到得用戶可能有多個, 所以返回值類型是數組, 但是對於iOS下, 就要隻有一個用戶, 所以數組中隻有一個元素
    /*
    NSString *documentsPath = [NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES) firstObject];
    //2)拼接上要存儲文件的路徑
    NSString *newFilePath = [documentsPath stringByAppendingPathComponent:@"aa.txt"];
    NSLog(@"%@", newFilePath);
     */
    NSString *filePath = [NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES) firstObject];
    NSString *newPath = [filePath stringByAppendingPathComponent:@"test.txt"];
    NSLog(@"%@", newPath);
    return newPath;
}

- (void)read:(UIButton *)button
{
    //每次寫入都會將之前的內容覆蓋掉, 若想保留之前的數據, 需要講之前的數據讀出, 然後將要存儲的數據拼接在一起, 一起存入
    /*
    NSString *newFilePath = [self getFilePath];
    NSError *error = nil;
    NSString *content = [NSString stringWithContentsOfFile:newFilePath encoding:NSUTF8StringEncoding error:&error];
    UITextField *tf = (UITextField *)[self.view viewWithTag:101];
    tf.text = content;
     */
    //字符串從本地讀取
    /*
    NSString *filePath = [self getFilePath];
    NSString *content = [NSString stringWithContentsOfFile:filePath encoding:NSUTF8StringEncoding error:nil];
    UITextField *tf = (UITextField *)[self.view viewWithTag:101];
    tf.text = content;
     */
    //數組從本地文件讀取
    NSString *filePath = [self getFilePath];
//    NSArray *arr = [NSArray arrayWithContentsOfFile:filePath];
    //從字典從本地讀取
    NSDictionary *dic = [NSDictionary dictionaryWithContentsOfFile:filePath];
    UITextField *tf = (UITextField *)[self.view viewWithTag:100];
    UITextField *tf1 = (UITextField *)[self.view viewWithTag:101];
    tf.text = dic[@"tf2"];
    tf1.text = dic[@"tf1"];
    
}
//文件讀寫暫時隻支持:NSString, NSArray, NSDictionary, NSData, 以及他們的子類.寫入文件:writeToFile:(這是對象調用的方法), 讀取文件:每一個類自帶的能夠根據路徑創建對象的方法:[類名 類WithContentsOfFile]; 字符串:[NSString stringWithContentsOfFile], 數組:[NSArray arrayWithContentsOfFile], 字典:[NSDictionary dictionaryWithContentsOfFile], 二進制流:[NSData dataWithContentsOfFile],(牢牢謹記:對於數組, 字典這樣的容器類, 內部的成員也必須是能夠實現文件讀寫的八大類之一)
- (void)write:(UIButton *)button
{
    //寫入時, 將第一個輸入框中的文字, 寫入到本地文件
    //1 獲取存儲的內容

    UITextField *tf = (UITextField *)[self.view viewWithTag:100];
    NSString *content = tf.text;
    //2 獲取到所要存儲的文件路徑
    //1)獲取Documents文件夾路徑
    NSString *newFilePath = [self getFilePath];
    //3 將內容存儲到指定文件路徑
//    NSError *error = nil;
     //字符串寫入本地文件
//    BOOL isSucceed = [content writeToFile:newFilePath atomically:YES encoding:NSUTF8StringEncoding error:&error];
     //數組寫入本地文件
    UITextField *tf2 = (UITextField *)[self.view viewWithTag:101];
    NSString *content1 = tf2.text;
//    NSArray *arr = @[content, content1];
//    BOOL isSucceed = [arr writeToFile:newFilePath atomically:YES];
    //字典寫入本地文件
    NSDictionary *dic = @{@"tf1": content, @"tf2": content1};
    BOOL isSucceed = [dic writeToFile:newFilePath atomically:YES];
    NSLog(@"%d", isSucceed);
    
}
- (void)push:(UIButton *)button
{
    WYLArchive *archivieVC = [[WYLArchive alloc]init];
    [self.navigationController  pushViewController:archivieVC animated:YES];
}
- (BOOL)textFieldShouldReturn:(UITextField *)textField
{
    [textField resignFirstResponder];
    return YES;
}
- (void)didReceiveMemoryWarning
{
    [super didReceiveMemoryWarning];
    // Dispose of any resources that can be recreated.
}

/*
#pragma mark - Navigation

// In a storyboard-based application, you will often want to do a little preparation before navigation
- (void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender
{
    // Get the new view controller using [segue destinationViewController].
    // Pass the selected object to the new view controller.
}
*/

@end

#import "WYLArchive.h"
#import "Person.h"
@interface WYLArchive ()

@end

@implementation WYLArchive

- (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil
{
    self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil];
    if (self) {
        // Custom initialization
    }
    return self;
}

- (void)viewDidLoad
{
    [super viewDidLoad];
    // Do any additional setup after loading the view.
    self.view.backgroundColor = [UIColor whiteColor];
    self.navigationItem.title = @"歸檔與反歸檔";
    UITextField *textField = [[UITextField alloc]initWithFrame:CGRectMake(40, 84, 220, 40)];
    textField.tag = 100;
    textField.placeholder  = @"請輸入內容";
    textField.borderStyle = UITextBorderStyleRoundedRect;
    textField.delegate = self;
    [self.view addSubview:textField];
    [textField release];
    UITextField *textField2 = [[UITextField alloc]initWithFrame:CGRectMake(40, 174, 220, 40)];
    textField2.tag = 101;
    textField2.placeholder  = @"顯示上一個輸入框的內容";
    textField2.borderStyle = UITextBorderStyleRoundedRect;
    textField2.delegate = self;
    [self.view addSubview:textField2];
    [textField2 release];
    UIButton *fileButton = [UIButton buttonWithType:UIButtonTypeSystem];
    fileButton.frame =  CGRectMake(45, 260, 60, 30);
    [fileButton setTitle:@"歸檔" forState:UIControlStateNormal];
    [fileButton addTarget:self action:@selector(file:) forControlEvents:UIControlEventTouchUpInside];
    [self.view addSubview:fileButton];
    UIButton *archiveButton = [UIButton buttonWithType:UIButtonTypeSystem];
    archiveButton.frame = CGRectMake(190, 260, 60, 30);
    [archiveButton setTitle:@"反歸檔" forState:UIControlStateNormal];
    [archiveButton addTarget:self action:@selector(archive:) forControlEvents:UIControlEventTouchUpInside];
    [self.view addSubview:archiveButton];

}

- (NSString *)getPath
{
    //獲得文件夾的路徑
    /*
    NSString *filePath = [NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES) firstObject];
    NSString *newPath = [filePath stringByAppendingPathComponent:@"archive"];
    return newPath;
     */
    NSString *path = [NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES) firstObject];
    NSString *newPath = [path stringByAppendingPathComponent:@"archiver"];
    return newPath;
}
- (void)file:(UIButton *)button
{
    //獲取輸入框的內容
    UITextField *tf1 = (UITextField *)[self.view viewWithTag:100];
    UITextField *tf2 = (UITextField *)[self.view viewWithTag:101];
    /*
    //封裝成Person對象
    Person *person = [[Person alloc] initWithName:tf1.text gender:tf2.text age:18];
    //1 創建歸檔對象
    NSMutableData *data = [NSMutableData data];
    NSKeyedArchiver *archiver = [[NSKeyedArchiver alloc] initForWritingWithMutableData:data];
    //2 歸檔
    [archiver encodeObject:person forKey:@"person"];
    [person release];
    //3 結束歸檔, 當結束歸檔之後, 再歸檔無效
    [archiver finishEncoding];
    [archiver release];
    //4 data寫入文件
    [data writeToFile:[self getPath] atomically:YES];
     */
    Person *person = [[Person alloc] initWithName:tf1.text gender:tf2.text age:18];
    NSMutableData *data = [NSMutableData data];
    NSKeyedArchiver *archiver = [[NSKeyedArchiver alloc] initForWritingWithMutableData:data];
    [archiver encodeObject:person forKey:@"archiver"];
    [person release];
    [archiver finishEncoding];
    [archiver release];
    [data writeToFile:[self getPath] atomically:YES];
}
- (void)archive:(UIButton *)button
{
    /*
    //1 初始化NSMutableData對象
    NSMutableData *data = [NSMutableData dataWithContentsOfFile:[self getPath]];
    //2 創建一個反歸檔對象
    NSKeyedUnarchiver *unarchiver = [[NSKeyedUnarchiver alloc] initForReadingWithData:data];
    //3 反歸檔
    Person *person = [unarchiver decodeObjectForKey:@"person"];
    //4 結束反歸檔
    [unarchiver finishDecoding];
    [unarchiver release];
     */
    NSMutableData *data = [NSMutableData dataWithContentsOfFile:[self getPath]];
    NSKeyedUnarchiver *unarchive = [[NSKeyedUnarchiver alloc] initForReadingWithData:data];
    Person *person = [unarchive decodeObjectForKey:@"archiver"];
    [unarchive finishDecoding];
    [unarchive release];
    UITextField *tf1 = (UITextField *)[self.view viewWithTag:100];
    UITextField *tf2 = (UITextField *)[self.view viewWithTag:101];
    tf1.text = person.gender;
    tf2.text = person.name;
}
- (BOOL)textFieldShouldReturn:(UITextField *)textField
{
    [textField resignFirstResponder];
    return YES;
}
- (void)didReceiveMemoryWarning
{
    [super didReceiveMemoryWarning];
    // Dispose of any resources that can be recreated.
}

/*
#pragma mark - Navigation

// In a storyboard-based application, you will often want to do a little preparation before navigation
- (void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender
{
    // Get the new view controller using [segue destinationViewController].
    // Pass the selected object to the new view controller.
}
*/

@end

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