Object-C 基础之6 — 文件类的各种操作方法

悠悠 2022-09-30 00:36 218阅读 0赞

本文来讲述 文件类的各种操作方法，示例如下：

NSString \*fName=@"testfile.m"; NSFileManager \*fm=NULL; NSDictionary \*dict=NULL; fm=\[NSFileManager defaultManager\]; if (\[fm fileExistsAtPath:fName\]==NO) \{ NSLog(@"file not exist!"); return 1; \} if (\[fm copyPath:fName toPath:@"newfile" handler:nil\]==NO) \{ NSLog(@"copy failed!"); \} if (\[fm movePath:@"newfile" toPath:@"newfolder" handler:nil\]==NO) \{ NSLog(@"move failed"); \} if ((dict=\[fm fileAttributesAtPath:@"newfolder" traverseLink:NO\])==nil) \{ NSLog(@"get file attributes failed"); \} NSLog(@"file size is %i bytes",\[\[dict objectForKey:NSFileSize\] intValue\]); if (\[fm removeFileAtPath:@"newfolder" handler:nil\]==YES) \{ NSLog(@"remove successful!"); \}

NSData类的使用方法

NSData \*fileData=NULL; fm=\[NSFileManager defaultManager\]; fileData=\[fm contentsAtPath:@"testfile.m"\]; if (fileData==nil) \{ NSLog(@"read file failed!"); \} if (\[fm createFileAtPath:@"file2" contents:fileData attributes:nil\]==YES) \{ NSLog(@"create file success!"); \}

对路径的操作方法：

NSString \*fName=@"testDir"; NSFileManager \*fm=NULL; //NSDictionary \*dict=NULL; NSString \*path=NULL; fm=\[NSFileManager defaultManager\]; path=\[fm currentDirectoryPath\]; NSLog(@"currentDir is: %@",path); //create a new directory \[fm createDirectoryAtPath:fName attributes:nil\]; //rename the directory \[fm movePath:fName toPath:@"newDir" handler:nil\]; //change currentdirectory \[fm changeCurrentDirectoryPath:@"newDir"\]; path=\[fm currentDirectoryPath\]; NSLog(@"currentDir is: %@",path);

枚举某个目录的所有内容：

NSFileManager \*fm=NULL; NSDirectoryEnumerator \*dirEnum=NULL; NSArray \*dirArray=NULL; NSString \*path=NULL; fm=\[NSFileManager defaultManager\]; path=\[fm currentDirectoryPath\]; dirEnum=\[fm enumeratorAtPath:path\]; while ((path=\[dirEnum nextObject\])!=nil) \{ dirArray=\[fm directoryContentsAtPath:\[fm currentDirectoryPath\]\]; \} NSLog(@"%@",dirArray);

NSFileHandle的使用示例：

NSFileHandle \*inFile, \*outFile; NSData \*buffer; inFile=\[NSFileHandle fileHandleForReadingAtPath:@"testfile.m"\]; \[\[NSFileManager defaultManager\]createFileAtPath:@"newfile1" contents:nil attributes:nil\]; outFile=\[NSFileHandle fileHandleForWritingAtPath:@"newfile1"\]; \[outFile truncateFileAtOffset:0\]; buffer=\[inFile readDataToEndOfFile\]; \[outFile writeData:buffer\]; \[inFile closeFile\]; \[outFile closeFile\];