iOS开发学无止境 - NSFileManager文件操作的十个小功能

 

（配图的小故事还记得嘛）

 

 

NSFileManager是一个单列类，也是一个文件管理器。可以通过NSFileManager创建文件夹、创建文件、写文件、读文件内容等等基本功能。

下面将介绍NSFileManager文件操作的十个小功能。我们在Documents里面进行举例，首先是获取Documents的路径。这个在iOS开发之沙盒机制（SandBox)已经详细讲解过了。获取Documents路径方法如下：

- (NSString *)getDocumentsPath
{//获取Documents路径NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);NSString *path = [paths objectAtIndex:0];NSLog(@"path:%@", path);return path;
}

创建文件夹

-(void)createDirectory{NSString *documentsPath =[self getDocumentsPath];NSFileManager *fileManager = [NSFileManager defaultManager];NSString *iOSDirectory = [documentsPath stringByAppendingPathComponent:@"iOS"];BOOL isSuccess = [fileManager createDirectoryAtPath:iOSDirectory withIntermediateDirectories:YES attributes:nil error:nil];if (isSuccess) {NSLog(@"success");} else {NSLog(@"fail");}
}

创建文件

-(void)createFile{NSString *documentsPath =[self getDocumentsPath];NSFileManager *fileManager = [NSFileManager defaultManager];NSString *iOSPath = [documentsPath stringByAppendingPathComponent:@"iOS.txt"];BOOL isSuccess = [fileManager createFileAtPath:iOSPath contents:nil attributes:nil];if (isSuccess) {NSLog(@"success");} else {NSLog(@"fail");}
}

写文件

-(void)writeFile{NSString *documentsPath =[self getDocumentsPath];NSString *iOSPath = [documentsPath stringByAppendingPathComponent:@"iOS.txt"];NSString *content = @"我要写数据啦";BOOL isSuccess = [content writeToFile:iOSPath atomically:YES encoding:NSUTF8StringEncoding error:nil];if (isSuccess) {NSLog(@"write success");} else {NSLog(@"write fail");}
}

读取文件内容

-(void)readFileContent{NSString *documentsPath =[self getDocumentsPath];NSString *iOSPath = [documentsPath stringByAppendingPathComponent:@"iOS.txt"];NSString *content = [NSString stringWithContentsOfFile:iOSPath encoding:NSUTF8StringEncoding error:nil];NSLog(@"read success: %@",content);
}

判断文件是否存在

- (BOOL)isSxistAtPath:(NSString *)filePath{NSFileManager *fileManager = [NSFileManager defaultManager];BOOL isExist = [fileManager fileExistsAtPath:filePath];return isExist;
}

计算文件大小

- (unsigned long long)fileSizeAtPath:(NSString *)filePath{NSFileManager *fileManager = [NSFileManager defaultManager];BOOL isExist = [fileManager fileExistsAtPath:filePath];if (isExist){unsigned long long fileSize = [[fileManager attributesOfItemAtPath:filePath error:nil] fileSize];return fileSize;} else {NSLog(@"file is not exist");return 0;}
}

计算整个文件夹中所有文件大小

- (unsigned long long)folderSizeAtPath:(NSString*)folderPath{NSFileManager *fileManager = [NSFileManager defaultManager];BOOL isExist = [fileManager fileExistsAtPath:folderPath];if (isExist){NSEnumerator *childFileEnumerator = [[fileManager subpathsAtPath:folderPath] objectEnumerator];unsigned long long folderSize = 0;NSString *fileName = @"";while ((fileName = [childFileEnumerator nextObject]) != nil){NSString* fileAbsolutePath = [folderPath stringByAppendingPathComponent:fileName];folderSize += [self fileSizeAtPath:fileAbsolutePath];}return folderSize / (1024.0 * 1024.0);} else {NSLog(@"file is not exist");return 0;}
}

删除文件

-(void)deleteFile{NSString *documentsPath =[self getDocumentsPath];NSFileManager *fileManager = [NSFileManager defaultManager];NSString *iOSPath = [documentsPath stringByAppendingPathComponent:@"iOS.txt"];BOOL isSuccess = [fileManager removeItemAtPath:iOSPath error:nil];if (isSuccess) {NSLog(@"delete success");}else{NSLog(@"delete fail");}
}

移动文件

- (void)moveFileName
{NSString *documentsPath =[self getDocumentsPath];NSFileManager *fileManager = [NSFileManager defaultManager];NSString *filePath = [documentsPath stringByAppendingPathComponent:@"iOS.txt"];NSString *moveToPath = [documentsPath stringByAppendingPathComponent:@"iOS.txt"];BOOL isSuccess = [fileManager moveItemAtPath:filePath toPath:moveToPath error:nil];if (isSuccess) {NSLog(@"rename success");}else{NSLog(@"rename fail");}
}

重命名

- (void)renameFileName
{//通过移动该文件对文件重命名NSString *documentsPath =[self getDocumentsPath];NSFileManager *fileManager = [NSFileManager defaultManager];NSString *filePath = [documentsPath stringByAppendingPathComponent:@"iOS.txt"];NSString *moveToPath = [documentsPath stringByAppendingPathComponent:@"rename.txt"];BOOL isSuccess = [fileManager moveItemAtPath:filePath toPath:moveToPath error:nil];if (isSuccess) {NSLog(@"rename success");}else{NSLog(@"rename fail");}
}

以上文件操作代码都在iOSStrongDemo，可以直接通过git拉下来进行测试。关于NSFileManager的用法还有很多，一起接续探索吧！