iOS開發學無止境 - NSFileManager文件操作的十個小功能

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（配圖的小故事還記得嘛）

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NSFileManager是一個單列類，也是一個文件管理器。可以通過NSFileManager創建文件夾、創建文件、寫文件、讀文件內容等等基本功能。

下面將介紹NSFileManager文件操作的十個小功能。我們在Documents里面進行舉例，首先是獲取Documents的路徑。這個在iOS開發之沙盒機制（SandBox)已經詳細講解過了。獲取Documents路徑方法如下：

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

創建文件夾

-(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");}
}

創建文件

-(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");}
}

寫文件

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

讀取文件內容

-(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);
}

判斷文件是否存在

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

計算文件大小

- (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;}
}

計算整個文件夾中所有文件大小

- (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;}
}

刪除文件

-(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");}
}

移動文件

- (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
{//通過移動該文件對文件重命名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");}
}

以上文件操作代碼都在iOSStrongDemo，可以直接通過git拉下來進行測試。關于NSFileManager的用法還有很多，一起接續探索吧！