文件操作

// file:///var/containers/Bundle/Application/4256C1D8-84BC-4F4C-A5A2-BCAAF8A83D2C/OTC_heartStick.app/pack_demo.txt
    // url读取是以 file://开始的
    NSURL *urlDemo = [[NSBundle mainBundle] URLForResource:@"pack_demo.txt" withExtension:nil];
    // 没有中文情况下可以使用  直接转string类型数据
    NSString *urlString = [urlDemo absoluteString];
    NSLog(@"%@", urlString);
    NSString *contentOne = [NSString stringWithContentsOfURL:urlDemo encoding:NSUTF8StringEncoding error:nil];
    
    // 直接以/xxxx/xxx，，，，开始
    NSString *path = [[NSBundle mainBundle] pathForResource:@"pack_demo.txt" ofType:nil];
    // 获取内容
    NSString *contenttwo = [NSString stringWithContentsOfFile:path encoding:NSUTF8StringEncoding error:nil];
    NSLog(@"%@---%@", contentOne, contenttwo);
    
    // 返回路径的组成部分 <__NSArrayM 0x100956340>(
//    /,
//    var,
//    containers,
//    Bundle,
//    Application,
//    0B43ABDC-17AA-4BA3-BF10-B0DC129A2D07,
//    OTC_heartStick.app,
//    pack_demo.txt
//    )
    NSArray *patharray = [path pathComponents];
    NSLog(@"%@", patharray);
    // 返回路径最后组成部分 txt
    NSString *str = [path lastPathComponent];
    // 这种方式有一点不好，就是需要添加/
    [path stringByAppendingString:@"/appFile.text"];
    // 不需要添加/
    [path stringByAppendingPathComponent:@"appFile.text"];
    // 删除最后的组成部分
    str = [path stringByDeletingLastPathComponent];
    // 删除扩展名(.text被删除了)
    str = [path stringByDeletingPathExtension];
    // 获取扩展名
    str = [path pathExtension];
    // 添加扩展名
    [path stringByAppendingPathExtension:@".jpg"];
    
    //存储是有编码方式的，编程字节码
    //相当于Java中的解码和编码
    NSString *s = @"tsdfsdfsdfsdf";
    NSData *data = [s dataUsingEncoding:NSUTF8StringEncoding];
    s = [[NSString alloc] initWithData:data encoding:(NSUTF8StringEncoding)];
    
    //获取沙盒目录
    NSString *homePath = NSHomeDirectory();
    //在沙盒目录中创建一个文件file.text
    NSString *filePath = [homePath stringByAppendingPathComponent:@"Documents/file.text"];
    //NSFileManager是单利模式, 所以不能使用alloc+init创建
    NSFileManager *manager = [NSFileManager defaultManager];
    NSString *strone = @"无线互联";
    NSData *dataone = [strone dataUsingEncoding:NSUTF8StringEncoding];
    //参数：文件路径、文件内容、文件的属性
    BOOL sucess = [manager createFileAtPath:filePath contents:dataone attributes:nil];
    if(sucess){
        NSLog(@"文件创建成功");
    }else{
        NSLog(@"文件创建失败");
    }
    //创建文件夹
    NSString *filePaths = [homePath stringByAppendingPathComponent:@"Documents/file"];
    NSError *error;
    //需要传递一个创建失败的指针对象，记录创建失败的信息
    BOOL success1 = [manager createDirectoryAtPath:filePaths withIntermediateDirectories:YES attributes:nil error:&error];
    if(!success1){
        NSLog(@"创建成功");
    }else{
        NSLog(@"创建失败");
    }
    
    NSFileHandle *handle = [NSFileHandle fileHandleForReadingAtPath:path];
    NSFileManager *fileManager = [NSFileManager defaultManager];
    NSDictionary *fileAttr = [fileManager attributesOfItemAtPath:filePath error:nil];
    NSNumber *fileSize = [fileAttr objectForKey:NSFileSize];
    long long sizeValue = [fileSize longLongValue];
    NSLog(@"%@--%lld", fileSize, sizeValue);
    // 读取到文件后，使用特定支付分割
    NSArray *arrayString = [contenttwo componentsSeparatedByString:@"\r\n"];