文件管理类

输出结果

////  ViewController.m//  文件-复习////  Created by Dream or want some on 2017/4/17.//  Copyright © 2017年 刘桂根. All rights reserved.//#import "ViewController.h"//宏定义桌面路径#define PATH @"/Users/user/Desktop"@interface ViewController ()@end@implementation ViewController- (void)viewDidLoad {    [super viewDidLoad];    // Do any additional setup after loading the view, typically from a nib.    //文件管理类    NSFileManager* fm = [NSFileManager defaultManager];    //创建文件    [fm createFileAtPath:[NSString stringWithFormat:@"%@/%@", PATH, @"1.txt"] contents:nil attributes:nil];    //创建文件夹    [fm createDirectoryAtPath:[NSString stringWithFormat:@"%@/%@", PATH, @"1"] withIntermediateDirectories:YES attributes:nil error:nil];    //判断文件是否存在    BOOL have = [fm fileExistsAtPath:[NSString stringWithFormat:@"%@/%@", PATH, @"1.txt"]];    NSLog(@"判断文件是否存在 == %d", have);    //判断文件夹是否存在    BOOL isDir = YES;    BOOL have1 = [fm fileExistsAtPath:[NSString stringWithFormat:@"%@/%@", PATH, @"1"] isDirectory:&isDir];    NSLog(@"判断文件夹是否存在 == %d", have1);    //写入内容    NSString* str = @"此内容于(2017/04/17)写入 写入人:天才刘";    NSData* data = [str dataUsingEncoding:NSUTF8StringEncoding];    [data writeToFile:[NSString stringWithFormat:@"%@/%@", PATH, @"1.txt"] atomically:YES];    //复制文件    [fm copyItemAtPath:[NSString stringWithFormat:@"%@/%@", PATH, @"1.txt"] toPath:[NSString stringWithFormat:@"/Users/user/Downloads/%@",@"2.txt"] error:nil];    //移动文件    [fm moveItemAtPath:[NSString stringWithFormat:@"%@/%@", PATH, @"1.txt"] toPath:[NSString stringWithFormat:@"/Users/user/Downloads/%@",@"1.txt"] error:nil];    //读文件内容    NSData* data1 = [NSData dataWithContentsOfFile:[NSString stringWithFormat:@"/Users/user/Downloads/%@",@"1.txt"]];    NSString* str1 = [[NSString alloc]initWithData:data1 encoding:NSUTF8StringEncoding];    NSLog(@"文件内容 == %@", str1);    //移除文件    [fm removeItemAtPath:[NSString stringWithFormat:@"/Users/user/Downloads/%@",@"1.txt"] error:nil];    //深度遍历    NSLog(@"深度遍历 == %@", [fm subpathsAtPath:PATH]);    //浅度遍历    NSLog(@"浅度遍历 == %@", [fm contentsOfDirectoryAtPath:PATH error:nil]);    //以只读的方式创建文件操作类    NSFileHandle* fh = [NSFileHandle fileHandleForReadingAtPath:[NSString stringWithFormat:@"/Users/user/Downloads/%@",@"2.txt"]];    //读取6个长度的文本内容(中文每个字的长度为3)    NSData* data3 = [fh readDataOfLength:6];    NSString* str2 = [[NSString alloc]initWithData:data3 encoding:NSUTF8StringEncoding];    NSLog(@"读取6个长度的文本内容为 == %@", str2);    //调整文件指针到某个位置    [fh seekToFileOffset:6];    //把文件指针调整到末尾，默认是在开始的位置    [fh seekToEndOfFile];    //以只写的方式打开文件    NSFileHandle* fh1 = [NSFileHandle fileHandleForWritingAtPath:[NSString stringWithFormat:@"/Users/user/Downloads/%@",@"2.txt"]];    [fh1 seekToEndOfFile];    //写入内容，写入时默认是从开始的位置写入，出现的效果就是从开头替换之前的内容展示目前写人的内容，要想从末尾写入不覆盖之前的，必须调整文件指针到末尾    [fh1 writeData:data3];}- (void)didReceiveMemoryWarning {    [super didReceiveMemoryWarning];    // Dispose of any resources that can be recreated.}@end