关于ifstream在c ++中的seekg（）函数的问题？ [英] Question about seekg() function of ifstream in C++?

问题描述

我正在测试以下代码：

int _tmain(int argc, _TCHAR* argv[])
{
    int sum = 0;
    int x;
    ifstream inFile;

    inFile.open("test.txt");
    if (!inFile) {
        cout << "Unable to open file";
        exit(1); // terminate with error
    }

    while (inFile >> x) {
        cout << x << endl;
    }
    cout << "-----------------------------" << endl;
    // Reading from beggining file again
    inFile.seekg(0, ios::beg);
    while (inFile >> x) {
        cout << x << endl;
    }

    inFile.close();

    return 0;
}

在上面的代码中，我想读取文件，文件的开头并再次读取。
我使用 inFile.seekg（0，ios :: beg）; 返回到文件的开头，但它不工作？
任何人都可以帮助我吗？
感谢

In the above code, I want to read the file then moving the pointer to the beginning of the file and read again. I have used inFile.seekg(0, ios::beg); to get back to the beginning of the file but it does not work? Can anyone help me, please? Thanks

推荐答案

在寻找开始之前，您需要清除所有错误标志，否则不执行任何操作在流上：

Before you seek to the beginning, you need to clear all error flags, else no operations are done on the stream:

inFile.clear();
inFile.seekg(0,std::ios::beg);

这是因为 eof ，因为您到达文件的结尾。

That's because the eof bit will be set, because you reached the end of the file before.

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