二进制文件的打开方式

本文介绍了二进制文件的打开方式的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！ 问题描述

您好我想打开读取和写入二进制文件（没有截断，没有附加）。我使用模式R + B。我没有得到任何编译错误，但是当读什么我写我得到垃圾值。任何想法。

Hi I want to open a binary file for both reading and writing(without truncating, not appending). I use mode "r+b". I get no compiling errors but when read what I have written I get garbage values. Any idea.

但是，如果我打开文件写（模式为世行）..写入in..close，然后打开该文件进行读取（模式为RB），a和读取它，然后它工作正常。

But if I open the file for writing(mode as "wb")..write into in..close it and then open the file for reading(mode as "rb") aand read from it ,then it works fine.

推荐答案

当你打开读/写模式的文件，如R +，W +，你需要确保你的文件指针指向一个有效的位置。 fseek的（）这里是你的朋友。

When you open a file in read/write modes such as "r+", "w+", you need to make sure your file pointer points to a valid position. fseek() is your friend here.

此外，作为一个很好的做法，记得要经常从函数检查返回值。在这种情况下，也许你的FREAD（）都失败了没有你注意到它。

Also, as a good practice, remember to always check returned values from functions. In this case, maybe your fread() have failed without you noticing it.