沙盒机制和文件(三)

0、判断一个文件是否存在,传入全路径(fileExistsAtPath)

// 创建文件管理器
NSFileManager * fileManager = [NSFileManager defaultManager];

NSString * documents = [NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES)lastObject];
NSString * filePath = [documents stringByAppendingPathComponent:@"test"];

    // 判断一个文件是否存在,传入全路径
    if ([fileManager fileExistsAtPath:filePath]) {
        NSLog(@"it is exit");
    }

1、在Documents里创建目录

 NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
    NSString *documentsDirectory = [paths objectAtIndex:0];
    NSLog(@"documentsDirectory%@",documentsDirectory);
    NSFileManager *fileManager = [NSFileManager defaultManager];
    NSString *testDirectory = [documentsDirectory stringByAppendingPathComponent:@"test"];
    // 创建目录
    [fileManager createDirectoryAtPath:testDirectory withIntermediateDirectories:YES attributes:nil error:nil];

2、在目录下创建文件

 NSString *testPath = [testDirectory stringByAppendingPathComponent:@"test00.txt"];
 NSString *testPath2 = [testDirectory stringByAppendingPathComponent:@"test22.txt"];
 NSString *testPath3 = [testDirectory stringByAppendingPathComponent:@"test33.txt"];


 NSString *string = @"写入内容，write String";
 [fileManager createFileAtPath:testPath contents:[string  dataUsingEncoding:NSUTF8StringEncoding] attributes:nil];
 [fileManager createFileAtPath:testPath2 contents:[string  dataUsingEncoding:NSUTF8StringEncoding] attributes:nil];
 [fileManager createFileAtPath:testPath3 contents:[string  dataUsingEncoding:NSUTF8StringEncoding] attributes:nil];

3、获取目录列里所有文件名

两种方法获取：subpathsOfDirectoryAtPath 和subpathsAtPath

 NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
 NSString *documentsDirectory = [paths objectAtIndex:0];
 NSLog(@"documentsDirectory%@",documentsDirectory);
 NSFileManager *fileManage = [NSFileManager defaultManager];
 NSString *myDirectory = [documentsDirectory stringByAppendingPathComponent:@"test"];
 NSArray *file = [fileManage subpathsOfDirectoryAtPath: myDirectory error:nil];
 NSLog(@"%@",file);
 NSArray *files = [fileManage subpathsAtPath: myDirectory ];
 NSLog(@"%@",files);

4、fileManager使用操作当前目录

 //创建文件管理器
     NSFileManager *fileManager = [NSFileManager defaultManager];
     NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
     NSString *documentsDirectory = [paths objectAtIndex:0];
     //更改到待操作的目录下
     [fileManager changeCurrentDirectoryPath:[documentsDirectory stringByExpandingTildeInPath]];
     //创建文件fileName文件名称，contents文件的内容，如果开始没有内容可以设置为nil，attributes文件的属性，初始为nil
     NSString * fileName = @"testFileNSFileManager.txt";
     NSArray *array = [[NSArray alloc] initWithObjects:@"hello world",@"hello world1", @"hello world2",nil];
     [fileManager createFileAtPath:fileName contents:array attributes:nil];

5、删除文件

 [fileManager removeItemAtPath:fileName error:nil];