第一、NSFileHandle

NSFileManager類主要對(duì)文件的操作(刪除、修改、移動(dòng)、復(fù)制等)

NSFileHandle類主要對(duì)文件的內(nèi)容進(jìn)行讀取和寫入

第二、NSFileHandle類處理文件的步驟

創(chuàng)建一個(gè)NSFileHandle對(duì)象

對(duì)打開(kāi)的文件進(jìn)行I/0操作

關(guān)閉文件

可以使用NSFileHandle進(jìn)行斷點(diǎn)續(xù)傳

第三、實(shí)現(xiàn)查找功能的代碼：

NSString *homePath=NSHomeDirectory();

NSString *filePath=[homePath stringByAppendingPathComponent:@"Desktop/hello.rtf"];

NSFileHandle *fileHandle=[NSFileHandle fileHandleForReadingAtPath:filePath];

NSUInteger length=[fileHandle availableData].length;

[fileHandle seekToFileOffset:length/2];

NSData *data=[fileHandle readDataToEndOfFile];

NSString *str=[[NSString alloc] initWithData:data encoding:NSUTF8StringEncoding];

NSLog(@"%@",str);

第四、實(shí)現(xiàn)追加文件代碼：

NSString *homePath=NSHomeDirectory();

NSString *filePath=[homePath stringByAppendingPathComponent:@"Desktop/hello.rtf"];

NSFileHandle *fileHandle=[NSFileHandle fileHandleForUpdatingAtPath:filePath];

//[fileHandle seekToEndOfFile];

[fileHandle seekToFileOffset:10];

NSString *str=@"data";

NSData *data=[str dataUsingEncoding:NSUTF8StringEncoding];

[fileHandle writeData:data];

[fileHandle closeFile];

// insert code here...

NSLog(@"Hello, World!");

第五、實(shí)現(xiàn)復(fù)制文件的代碼：

NSString *homePath=NSHomeDirectory();

NSString *filePath=[homePath stringByAppendingPathComponent:@"Desktop/hello.rtf"];

NSString *objPath=[homePath stringByAppendingPathComponent:@"Desktop/copy.rtf"];

NSFileManager *fileManager=[NSFileManager defaultManager];

BOOL success=[fileManager createFileAtPath:objPath contents:nil attributes:nil];

NSFileHandle *writeFile=[NSFileHandle fileHandleForReadingAtPath:filePath];

NSFileHandle *objFile=[NSFileHandle fileHandleForWritingAtPath:objPath];

[objFile readDataToEndOfFile];

NSData *data=[writeFile readDataToEndOfFile];

[objFile writeData:data];

[writeFile closeFile];

[objFile closeFile];

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