02-IOSCore - NSFileHandle、合并文件、文件指针、文件查看器

- (void)viewDidLoad

{

    [super viewDidLoad];

    NSString *homePath = NSHomeDirectory();

    NSLog(@"%@",homePath);

    NSString *documentsPath = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES)[0];

    NSString *filePath = [documentsPath stringByAppendingPathComponent:@"hello.txt"];

    NSString *fileContent = @"你好";

    // 写入：

    // 怎么把fileContent写到hello.txt呢

    // 先把fileContent->NSData  ,  然后写到hello.txt中

   

    // NSString -> NSData

    NSData *data = [fileContent dataUsingEncoding:NSUTF8StringEncoding];

    // NSData -> 文件 完整步骤

    // 准备空文件hello.txt

    NSFileManager *fileManager = [NSFileManager defaultManager];

    [fileManager createFileAtPath:filePath contents:nil attributes:nil];

    // 创建文件对接器

    NSFileHandle *fileHandle = [NSFileHandle fileHandleForWritingAtPath:filePath];

    // 写入数据

    [fileHandle writeData:data];

    // 关闭文件对接器

    [fileHandle closeFile];

   

    // 写入文件还有更快捷的方法

//    [fileManager createFileAtPath:filePath contents:data attributes:nil];

   

    // 读取

    // 文件 -> NSData -> NSString

    // 创建文件对接器

    NSFileHandle *readHandle = [NSFileHandle fileHandleForReadingAtPath:filePath];

    // 读数据

    NSData *data1 = [readHandle readDataToEndOfFile];

    // 关闭对接器

    [readHandle closeFile];

    // data -> string

    NSString *str = [[NSString alloc] initWithData:data1 encoding:NSUTF8StringEncoding];

    NSLog(@"%@",str);

   

   

    // string根据路径可以直接获取数据

    NSString *str2 = [NSString stringWithContentsOfFile:filePath encoding:NSUTF8StringEncoding error:nil]; // 读取文件以UTF8显示

   

   

    // 识别编码

    NSStringEncoding encode;

    NSString *str3 = [NSString stringWithContentsOfFile:filePath usedEncoding:&encode error:nil]; // 该方法做了两件事，首先根据路径读取数据，然后把该数据的编码赋值给encode

    NSLog(@"%d",encode); // 4 表示UTF8编码

 

}

- (void)viewDidLoad

{

    [super viewDidLoad];

    NSLog(@"%@",NSHomeDirectory());

    NSString *documentsPath = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDirectory, YES)[0];

    NSString *filePath = [documentsPath stringByAppendingPathComponent:@"sourcefile.txt"];

    NSData *data = [@"中文!" dataUsingEncoding:NSUTF8StringEncoding];

   

    [[NSFileManager defaultManager] createFileAtPath:filePath contents:nil attributes:nil];

   

   

    [[NSFileManager defaultManager] createFileAtPath:filePath contents:data attributes:nil];

   

    // 文件 -> data

    NSFileHandle *readHandle = [NSFileHandle fileHandleForReadingAtPath:filePath];

    NSData *dataFromFile = [readHandle readDataToEndOfFile];

    // data -> 新文件copy.txt

    NSString *copyPath = [documentsPath stringByAppendingPathComponent:@"copy.txt"];

    [[NSFileManager defaultManager] createFileAtPath:copyPath contents:dataFromFile attributes:nil];

   

    // copy图片

    NSData *picData = [NSData dataWithContentsOfFile:@"/Users/.../01.jpg"];

    NSString *picPath = [documentsPath stringByAppendingPathComponent:@"01.jpg"];

    [[NSFileManager defaultManager] createFileAtPath:picPath contents:picData attributes:nil];

   

}

- (void)viewDidLoad

{

    [super viewDidLoad];

   

    NSLog(@"%@",NSHomeDirectory());

    // 获取documents路径

    NSString *documents = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES)[0];

    // 源文件名数组

    NSArray *sourceNames = @[@"a.txt", @"b.txt", @"c.txt",];

    // 合并文件名

    NSString *outputName = @"combine.txt";

    // 合并文件路径

    NSString *outputFilePath = [documents stringByAppendingPathComponent:outputName];

    // 创建合并文件

    [[NSFileManager defaultManager] createFileAtPath:outputFilePath contents:nil attributes:nil];

    // 创建filehandle

    NSFileHandle *writeHandle = [NSFileHandle fileHandleForWritingAtPath:outputFilePath];

    // 循环写入数据

    for (NSString *sourceName in sourceNames) {

        NSString *sourceFilePath = [documents stringByAppendingPathComponent:sourceName]; // 源文件路径

       

        NSFileHandle *readHandle = [NSFileHandle fileHandleForReadingAtPath:sourceFilePath]; // 创建读取handle

        NSData *readData = [readHandle readDataToEndOfFile]; // 读出数据

       

        [writeHandle writeData:readData]; // 写到新文件中

       

        [readHandle closeFile]; // 关闭读取文件

       

       

    }

    // 关闭文件

    [writeHandle closeFile];

}

- (void)viewDidLoad

{

    [super viewDidLoad];


   

    NSLog(@"%@",NSHomeDirectory());

   

    NSString *documentsPath = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES)[0];

   

    NSString *sourcePath = [documentsPath stringByAppendingPathComponent:@"source.txt"];

   

    // 按每次1000字节的中专 拷贝一张图片

    NSString *picPath = @"/Users/tarena/yz/第三阶段(UI核心_Model赵哲)/day02/1-4.jpg";

   

    // 拷贝

    // 创建读取handle

    NSFileHandle *readHandle = [NSFileHandle fileHandleForReadingAtPath:picPath];

    unsigned long long picSize = [readHandle seekToEndOfFile]; // 图片大小

    unsigned long long offset = 0;

    NSString *path = [documentsPath stringByAppendingPathComponent:@"0.jpg"]; // document下图片路径

    [[NSFileManager defaultManager] createFileAtPath:path contents:nil attributes:nil]; // 创建空jpg文件

    NSFileHandle *writeHandle = [NSFileHandle fileHandleForWritingAtPath:path]; // 创建写handle

   

    [readHandle seekToFileOffset:0]; // 设置文件指针

   

    // 循环读取文件写入到document下空的jpg文件

    NSData *data = nil;

    while (offset + 1000 <= picSize) { // 一次读1000

        data = [readHandle readDataOfLength:1000];

        [writeHandle writeData:data];

        offset += 1000;

        NSLog(@"%llu",offset);

    }

    // 不足1000的读到最后

    data = [readHandle readDataToEndOfFile];

    [writeHandle writeData:data];

    [readHandle closeFile];

    [writeHandle closeFile];

   

    // 文件指针的使用

    NSFileHandle *readHandle = [NSFileHandle fileHandleForReadingAtPath:sourcePath];

    unsigned long long fileSize = [readHandle seekToEndOfFile]; // 该方法会把文件指针移至最后并返回文件大小

    NSLog(@"%llu",fileSize);

    [readHandle seekToFileOffset:0]; // 设置指针位置

    NSData *data = [readHandle readDataOfLength:3]; // 读取长度 以字节为单位 一个汉子占3个字节

    NSString *str = [[NSString alloc] initWithData:data encoding:NSUTF8StringEncoding];

    NSLog(@"%@",str);

    [readHandle closeFile];

   

}

- (void)viewDidLoad

{

    [super viewDidLoad];

    if (!self.path) {

        self.path = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES)[0];

    }

   

    NSArray *fileNameArray = [[NSFileManager defaultManager] contentsOfDirectoryAtPath:self.path error:nil];

    self.files = [NSMutableArray array];

    for (NSString *fileName in fileNameArray) {

        NSString *filePath = [self.path stringByAppendingPathComponent:fileName];

        [self.files addObject:filePath];

    }

    NSLog(@"%@",self.files);

    // Uncomment the following line to preserve selection between presentations.

    // self.clearsSelectionOnViewWillAppear = NO;

 

    // Uncomment the following line to display an Edit button in the navigation bar for this view controller.

    // self.navigationItem.rightBarButtonItem = self.editButtonItem;

}

 

- (void)didReceiveMemoryWarning

{

    [super didReceiveMemoryWarning];

    // Dispose of any resources that can be recreated.

}

 

#pragma mark - Table view data source

 

- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section

{

    return self.files.count;

}

 

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath

{

    static NSString *CellIdentifier = @"Cell";

    UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier forIndexPath:indexPath];

   

    // Configure the cell...

    NSString *filePath = self.files[indexPath.row];

    if ([[filePath pathExtension] isEqualToString:@"jpg"]) {

        cell.textLabel.text = [filePath lastPathComponent];

        cell.imageView.image = [UIImage imageWithContentsOfFile:filePath];

    }else if([[filePath pathExtension] isEqualToString:@"txt"]){

        cell.textLabel.text = [filePath lastPathComponent];

    }else{ //目录

        cell.textLabel.text = [filePath lastPathComponent];

        [cell setAccessoryType:UITableViewCellAccessoryDisclosureIndicator];

    }

    return cell;

}

 

-(void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath{

    NSString *filePath = self.files[indexPath.row];

    if ([[filePath pathExtension] isEqualToString:@"jpg"]) {

        [self performSegueWithIdentifier:@"pictureVC" sender:filePath];

    }else if([[filePath pathExtension] isEqualToString:@"txt"]){

        [self performSegueWithIdentifier:@"txtVC" sender:filePath];

    }else{ //目录

        MXDocumentsViewController *docvc = [self.storyboard instantiateViewControllerWithIdentifier:@"fileListTV"];

        docvc.path = filePath;

        [self.navigationController pushViewController:docvc animated:YES];

    }

   

}

 

 #pragma mark - Navigation

 

 // In a story board-based application, you will often want to do a little preparation before navigation

 - (void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender

 {

     if ([segue.identifier isEqualToString:@"pictureVC"]) {

         MXPictureViewController *picvc = segue.destinationViewController;

         picvc.path = sender;

     }else if ([segue.identifier isEqualToString:@"txtVC"]){

         MXTxtViewController *txtvc = segue.destinationViewController;

         txtvc.path = sender;

     }

    

 }