详解iOS学习笔记（十七）——文件操作（NSFileManager）-移动开发

这篇文章主要介绍了详解iOS学习笔记（十七）——文件操作（NSFileManager），具有一定的参考价值，有需要的可以了解一下。

iOS的沙盒机制，应用只能访问自己应用目录下的文件。iOS不像Android，没有SD卡概念，不能直接访问图像、视频等内容。iOS应用产生的内容，如图像、文件、缓存内容等都必须存储在自己的沙盒内。默认情况下，每个沙盒含有3个文件夹：Documents, Library 和 tmp。Library包含Caches、Preferences目录。


-(void)dirHome{ 
  NSString *dirHome=NSHomeDirectory();   
  NSLog(@"app_home: %@",dirHome); 
}

获取Documents目录路径：


//获取Documents目录 
-(NSString *)dirDoc{ 
  //[NSHomeDirectory() stringByAppendingPathComponent:@"Documents"]; 
  NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES); 
  NSString *documentsDirectory = [paths objectAtIndex:0]; 
  NSLog(@"app_home_doc: %@",documentsDirectory); 
  return documentsDirectory; 
}

获取Library目录路径：


//获取Library目录 
-(void)dirLib{ 
  //[NSHomeDirectory() stringByAppendingPathComponent:@"Library"]; 
  NSArray *paths = NSSearchPathForDirectoriesInDomains(NSLibraryDirectory, NSUserDomainMask, YES); 
  NSString *libraryDirectory = [paths objectAtIndex:0]; 
  NSLog(@"app_home_lib: %@",libraryDirectory); 
}

获取Cache目录路径：


//获取Cache目录 
-(void)dirCache{ 
  NSArray *cacPath = NSSearchPathForDirectoriesInDomains(NSCachesDirectory, NSUserDomainMask, YES); 
  NSString *cachePath = [cacPath objectAtIndex:0]; 
  NSLog(@"app_home_lib_cache: %@",cachePath); 
}

获取Tmp目录路径：


//获取Tmp目录 
-(void)dirTmp{ 
  //[NSHomeDirectory() stringByAppendingPathComponent:@"tmp"]; 
  NSString *tmpDirectory = NSTemporaryDirectory(); 
  NSLog(@"app_home_tmp: %@",tmpDirectory); 
}

创建文件夹：


//创建文件夹 
-(void *)createDir{ 
  NSString *documentsPath =[self dirDoc]; 
  NSFileManager *fileManager = [NSFileManager defaultManager]; 
  NSString *testDirectory = [documentsPath stringByAppendingPathComponent:@"test"]; 
  // 创建目录 
  BOOL res=[fileManager createDirectoryAtPath:testDirectory withIntermediateDirectories:YES attributes:nil error:nil]; 
  if (res) { 
    NSLog(@"文件夹创建成功"); 
  }else 
    NSLog(@"文件夹创建失败"); 
 }

创建文件


 //创建文件 
-(void *)createFile{ 
  NSString *documentsPath =[self dirDoc]; 
  NSString *testDirectory = [documentsPath stringByAppendingPathComponent:@"test"]; 
  NSFileManager *fileManager = [NSFileManager defaultManager]; 
  NSString *testPath = [testDirectory stringByAppendingPathComponent:@"test.txt"]; 
  BOOL res=[fileManager createFileAtPath:testPath contents:nil attributes:nil]; 
  if (res) { 
    NSLog(@"文件创建成功: %@" ,testPath); 
  }else 
    NSLog(@"文件创建失败"); 
}

写数据到文件：


//写文件 
-(void)writeFile{ 
  NSString *documentsPath =[self dirDoc]; 
  NSString *testDirectory = [documentsPath stringByAppendingPathComponent:@"test"]; 
  NSString *testPath = [testDirectory stringByAppendingPathComponent:@"test.txt"]; 
  NSString *content=@"测试写入内容！"; 
  BOOL res=[content writeToFile:testPath atomically:YES encoding:NSUTF8StringEncoding error:nil]; 
  if (res) { 
    NSLog(@"文件写入成功"); 
  }else 
    NSLog(@"文件写入失败"); 
}

读文件数据：


//读文件 
-(void)readFile{ 
  NSString *documentsPath =[self dirDoc]; 
  NSString *testDirectory = [documentsPath stringByAppendingPathComponent:@"test"]; 
  NSString *testPath = [testDirectory stringByAppendingPathComponent:@"test.txt"]; 
//  NSData *data = [NSData dataWithContentsOfFile:testPath]; 
//  NSLog(@"文件读取成功: %@",[[NSString alloc] initWithData:data encoding:NSUTF8StringEncoding]); 
  NSString *content=[NSString stringWithContentsOfFile:testPath encoding:NSUTF8StringEncoding error:nil]; 
  NSLog(@"文件读取成功: %@",content); 
}

文件属性：


//文件属性 
-(void)fileAttriutes{ 
  NSString *documentsPath =[self dirDoc]; 
  NSString *testDirectory = [documentsPath stringByAppendingPathComponent:@"test"]; 
  NSFileManager *fileManager = [NSFileManager defaultManager]; 
  NSString *testPath = [testDirectory stringByAppendingPathComponent:@"test.txt"]; 
  NSDictionary *fileAttributes = [fileManager attributesOfItemAtPath:testPath error:nil];   
  NSArray *keys; 
  id key, value; 
  keys = [fileAttributes allKeys]; 
  int count = [keys count]; 
  for (int i = 0; i < count; i++) 
  { 
    key = [keys objectAtIndex: i]; 
    value = [fileAttributes objectForKey: key]; 
    NSLog (@"Key: %@ for value: %@", key, value); 
  } 
}

删除文件：


//删除文件 
-(void)deleteFile{ 
  NSString *documentsPath =[self dirDoc]; 
  NSString *testDirectory = [documentsPath stringByAppendingPathComponent:@"test"]; 
  NSFileManager *fileManager = [NSFileManager defaultManager]; 
  NSString *testPath = [testDirectory stringByAppendingPathComponent:@"test.txt"];   
  BOOL res=[fileManager removeItemAtPath:testPath error:nil]; 
  if (res) { 
    NSLog(@"文件删除成功"); 
  }else 
    NSLog(@"文件删除失败");   
  NSLog(@"文件是否存在: %@",[fileManager isExecutableFileAtPath:testPath]?@"YES":@"NO"); 
}

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