无法使用 while(file.read(reinterpret_cast<char *>(&myStruct),sizeof(STRUCT))) 读取结构二进制文件两次

Question

无法从结构二进制文件读取两次。我想打开并读取结构的二进制文件。代码中的注释说明。第一个循环有效，但第二个循环被完全绕过。

#include <iostream>
#include <fstream>
#include <iomanip> // this library stored the std::setw

using namespace std;

int main()
{
    cout << "\n Hello world!" << endl;

struct STRUCT{
    int x;
    int y;
};
STRUCT myStruct;

fstream file;
file.open("c:read.dat",std::fstream::binary | std::fstream::in | std::fstream::out);

while(file.read(reinterpret_cast<char*>(&myStruct),sizeof(STRUCT))){
        cout << "\n" << setw(14) << "t1" << setw(14) << "t1";// test inside loop
        cout << "\n" << setw(14) << myStruct.x << setw(14) << myStruct.y ;
        };
// Above will work and print
file.clear(); // **This worked. Thank you.**
file.seekg(0, ios::beg);
file.seekp(0, ios::beg);   
// below printed after inserting file.clear() before file.seekg(0, ios::beg);
while(file.read(reinterpret_cast<char*>(&myStruct),sizeof(STRUCT))){
        cout << "\n" << setw(14) << "q" << setw(14) << "q";// test inside loop
        cout << "\n" << setw(14) << myStruct.x << setw(14) << myStruct.y ;
        };
cout << "\n The End";
return 0;
}