前面我在介紹iOS應(yīng)用存儲(chǔ)數(shù)據(jù)的常用的方式之plist和歸檔的時(shí)候,我們一般存儲(chǔ)數(shù)據(jù)或者寫(xiě)入數(shù)據(jù)都要建立一個(gè)
文件或者文件夾,所以NSFileManager在我們?nèi)粘ｉ_(kāi)發(fā)中會(huì)經(jīng)常使用到,這里稍微介紹一下在日常開(kāi)發(fā)過(guò)程中,我們會(huì)經(jīng)常對(duì)數(shù)據(jù)進(jìn)行操作,那么這就會(huì)使用到今天我要介紹的
NSFileManager的類,這個(gè)對(duì)類是文件和文件夾的操作-
NSFileManager使用了單例模式
- 使用
defaultManager方法可以獲得那個(gè)單例對(duì)象objc ``[NSFileManager defaultManager]
- 使用
NSFileManager用法
1.文件/文件夾判斷
1 - 判斷文件或者文件夾是否存在
- (BOOL)fileExistsAtPath:(NSString *)path
NSFileManager *manager = [NSFileManager defaultManager];
NSString *path = @"/Users/it001/Desktop/timg.jpeg";
if ([manager fileExistsAtPath:path]) {
NSLog(@"存在");
}else{
NSLog(@"不存在");
}
2 - 判斷文件或者文件夾是否存在,
isDirectory代表是否為文件夾
- (BOOL)fileExistsAtPath:(NSString *)path isDirectory:(BOOL *)isDirectory;
NSFileManager *manager = [NSFileManager defaultManager];
NSString *path = @"/Users/it001/Desktop/100";
//
BOOL isdir = NO;
//isDirectory 傳入的是一個(gè)內(nèi)存地址,如果這個(gè)文件夾真是存在就是yes,如果不存在就是NO
BOOL isSuc = [manager fileExistsAtPath:path isDirectory:&isdir];
NSLog(@"%@---%@",isSuc == YES?@"yes":@"NO",isdir == YES ?@"yes":@"no");
打印結(jié)果:yes----yes
3- 下面的方法和上面的是一樣 不做例子
-
- (BOOL)isReadableFileAtPath:(NSString *)path;- path這個(gè)文件\文件夾是否可讀
-
- (BOOL)isWritableFileAtPath:(NSString *)path;- path這個(gè)文件\文件夾是否可寫(xiě)
- 系統(tǒng)目錄不允許寫(xiě)入
-
- (BOOL)isDeletableFileAtPath:(NSString *)path;- path這個(gè)文件\文件夾是否可刪除
- 系統(tǒng)目錄不允許刪除
2.文件的訪問(wèn)
1- 獲取文件/文件夾的屬性(比如:名稱,創(chuàng)建日期,大小,修改時(shí)間)
- (NSDictionary *)attributesOfItemAtPath:(NSString *)path error:(NSError **)error;
NSFileManager *manager = [NSFileManager defaultManager];
NSString *path = @"/Users/it001/Desktop/timg.jpeg";
NSDictionary *fileInfo = [manager attributesOfItemAtPath:path error:nil];
NSLog(@"%@",fileInfo);
//打印結(jié)果
{
//創(chuàng)建的日期
NSFileCreationDate = "2019-02-12 14:39:02 +0000";
//屬性字典對(duì)象
NSFileExtendedAttributes = {
"com.apple.lastuseddate#PS" = <8162885c 00000000 64cd143b 00000000>;
"com.apple.metadata:_kMDItemUserTags" = <62706c69 73743030 a0080000 00000000 01010000 00000000 00010000 00000000 00000000 00000000 0009>;
"com.apple.metadata:kMDItemWhereFroms" = 03f8>;
"com.apple.quarantine" = <30303833 3b356336 32646138 623b4368 726f6d65 3b434446 39344535 442d4330 43432d34 3844312d 38463034 2d453234 36374430 38414131 45>;
};
NSFileExtensionHidden = 0;
NSFileGroupOwnerAccountID = 20;
NSFileGroupOwnerAccountName = staff;
//修改時(shí)間
NSFileModificationDate = "2019-02-12 14:39:02 +0000";
NSFileOwnerAccountID = 501;
NSFilePosixPermissions = 420;
NSFileReferenceCount = 1;
//文件大小
NSFileSize = 49881;
NSFileSystemFileNumber = 8595530012;
NSFileSystemNumber = 16777220;
NSFileType = NSFileTypeRegular;
2-獲取文件內(nèi)存 NSData數(shù)據(jù)
- (NSData *)contentsAtPath:(NSString *)path;
+ 獲得文件內(nèi)容
NSFileManager *manager = [NSFileManager defaultManager];
NSString *path = @"/Users/lijunchao/Desktop/timg.jpeg";
NSData *contents = [manager contentsAtPath:path];
NSLog(@"%@",contents);
3 - 獲取當(dāng)前path的所有文件(包含子文件夾,但是不會(huì)包含子文件夾里面的內(nèi)容)
- (NSArray *)contentsOfDirectoryAtPath:(NSString *)path error:(NSError *)error;
NSFileManager *manager = [NSFileManager defaultManager];
NSString *path = @"/Users/lijunchao/Desktop/100";
NSArray *contents = [manager contentsOfDirectoryAtPath:path error:nil];
NSLog(@"%@",contents);
(
abc, //abc子文件夾,沒(méi)有子文件夾里面的內(nèi)容
".DS_Store",
"IMG_1436.PNG",
"31.txt"
)
4 - 獲取所有文件或者文件夾
- (NSArray *)subpathsAtPath:(NSString *)path;
- (NSArray *)subpathsOfDirectoryAtPath:(NSString *)path error:(NSError *)error;
NSFileManager *manager = [NSFileManager defaultManager];
NSString *path = @"/Users/lijunchao/Desktop/100";
NSArray *contents = [manager subpathsAtPath:path];
NSLog(@"%@",contents);
//打印結(jié)果:獲取到子文件夾里面的內(nèi)容
(
abc,
"abc/KVC\U548cKVO\U7684\U4ecb\U7ecd.md",
".DS_Store",
"IMG_1436.PNG",
"31.txt"
)
3.NSFileManager的文件操作
1- 文件的拷貝
- (BOOL)copyItemAtPath:(NSString *)srcPath toPath:(NSString *)dstPath error:(NSError **)error;
NSFileManager *manager = [NSFileManager defaultManager];
//需要注意是路徑,在copy的到toPath的時(shí)候文件是不存在的,
NSString *path = @"/Users/it001/Desktop/timg.jpeg";
NSString *toPath = @"/Users/it001/Desktop/100/timg.jpeg";
NSError *error = nil;
BOOL isSuc = [manager copyItemAtPath:path toPath:toPath error:&error];
NSLog(@"%@",error.description);
NSLog(@"%@",(isSuc == YES?@"copy成功":@"失敗"));
2- 文件的移動(dòng)(剪切)
- (BOOL)moveItemAtPath:(NSString *)srcPath toPath:(NSString *)dstPath error:(NSError **)error;
NSFileManager *manager = [NSFileManager defaultManager];
NSString *path = @"/Users/it001/Desktop/timg.jpeg";
NSString *toPath = @"/Users/it001/Desktop/100/timg.jpeg";
BOOL isSuc = [manager moveItemAtPath:path toPath:toPath error:nil];
NSLog(@"%@",(isSuc == YES?@"copy成功":@"失敗"));
3- 文件的刪除
- (BOOL)removeItemAtPath:(NSString *)path error:(NSError **)error;
NSFileManager *manager = [NSFileManager defaultManager];
NSString *toPath = @"/Users/it001/Desktop/100/timg.jpeg";
BOOL isSuc = [manager removeItemAtPath:toPath error:nil];
NSLog(@"%@",(isSuc == YES?@"刪除成功":@"失敗"));
4- 文件夾的創(chuàng)建
- (BOOL)createDirectoryAtPath:(NSString *)path withIntermediateDirectories:(BOOL)createIntermediates attributes:(NSDictionary *)attributes error:(NSError **)error;
創(chuàng)建文件夾(createIntermediates為YES代表自動(dòng)創(chuàng)建中間的文件夾)
NSFileManager *manager = [NSFileManager defaultManager];
NSString *toPath = @"/Users/it001/Desktop/100/CC/timg.jpeg";
BOOL isSuc = [manager createDirectoryAtPath:toPath withIntermediateDirectories:YES attributes:nil error:nil];
NSLog(@"%@",(isSuc == YES?@"創(chuàng)建成功":@"失敗"));
5- 文件的創(chuàng)建
- (BOOL)createFileAtPath:(NSString *)path contents:(NSData *)data attributes:(NSDictionary *)attr;
創(chuàng)建文件(NSData是用來(lái)存儲(chǔ)二進(jìn)制字節(jié)數(shù)據(jù)的)
NSString *str = @"CC";
NSData *data = [str dataUsingEncoding:NSUTF8StringEncoding];
NSFileManager *manager = [NSFileManager defaultManager];
BOOL isSuc = [manager createFileAtPath:@"/Users/it001/Desktop/100/abc.txt" contents:data attributes:nil];
NSLog(@"%@",(isSuc == YES?@"創(chuàng)建成功":@"失敗"));
