将文件读入缓冲区 [英] reading file into buffer

问题描述

我正在将文件的内容读取到缓冲区中，以准备在MFC应用程序中填充窗口.

我的代码是:

I am reading the contents of a file into a bufer ready to populate a window in an MFC app.

My code is:

    //read file
CFile* pFile = new CFile(filePathAndName, CFile::modeRead);
ULONGLONG dwLength = pFile->GetLength();//I64u
char* buffer = new char[(int)dwLength];
UINT nActual = pFile->Read(buffer, dwLength);//sizeof(szBuffer));

但是，我总是在缓冲区的末尾得到大约10-12个字符的垃圾-通常看起来是这样的:
ýýýý««««««««îþ

谁能告诉我这是哪里来的，以及如何将其删除.如果文件为空，我什至可以得到它.

However, I lways get about 10-12 characters of garbage right at the end of the buffer - it usually looks something like:
ýýýý««««««««îþîþ

Can anyone tell me where this comes from and how to remove it please. I even get it if the file is empty.

推荐答案

Dave的答案是绝对正确的，但是更好的解决方法是

Dave''s answer is absolutely correct, however a better solution to the problem would be

//read file
CFile* pFile = new CFile(filePathAndName, CFile::modeRead);
ULONGLONG dwLength = pFile->GetLength();//I64u
char* buffer = new char[(int)dwLength + 1]; //Notice the +1
buffer[dwLength] = 0; //This will make the last character a null terminator
UINT nActual = pFile->Read(buffer, dwLength);//sizeof(szBuffer));

这将使您可以将文件内容与任何C ++函数一起用作普通字符串

This will allow you to use the file contents with any C++ function as a normal string

像这样读取时没有空终止符-因此您要添加缓冲区的末尾-什么设置字符串时的一行?您需要确保仅使用nActual字符-否则最后将得到垃圾:)

There is no null terminating character when reading like this - so you are adding the end of the buffer - what''s the line when you set your string? You need to make sure you use nActual characters only - otherwise you''ll get garbage at the end :)

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