c++ - GetAsyncKeyState(VK_RETURN)遭遇

Question

我正在尝试做一个滚动菜单。我的问题在于

GetAsyncKeyState(VK_RETURN)

我输入信息后，没有返回到我的菜单。它突然要求我输入另一个信息(这是无穷无尽的)。

我不确定它是否与 GetAsyncKeyState(VK_RETURN) 语句一起使用，因为每次我尝试输入最后一个信息(即“输入年份”)时，它都会返回到菜单，但会自动按 Enter 键“输入学生”选项。

#include<stdio.h>
#include<stdlib.h>
#include<string.h>
#include<conio.h>
#include<windows.h>
#include<iostream>

using namespace std;

typedef struct{
 char fname[24],lname[16],mi,course[16];
 int year;
 unsigned long ID;
 }studtype;

 void getStudent(void);
 void getHeader();
 void readToFile(void);
// FILE * openFile(FILE *);
// void closeFile(FILE *);
// studtype *writeFile(studtype *,FILE *);



 int main(void)
 {
    char* Menu[2];
    Menu[0] = "Input Student";
    Menu[1] = "Display Student";

    int choice;
    int pointer = 0;
    while(true)
    {
            system("cls");

            SetConsoleTextAttribute(GetStdHandle(STD_OUTPUT_HANDLE), 15);
            printf("Main Menu\n\n");

            for (int i = 0; i < 2; ++i)
            {
                 if (i == pointer)
                 {
                        SetConsoleTextAttribute(GetStdHandle(STD_OUTPUT_HANDLE), 11);
                        cout << Menu[i] << endl;
                 }
                 else
                 {
                        SetConsoleTextAttribute(GetStdHandle(STD_OUTPUT_HANDLE), 15);
                        cout << Menu[i] << endl;
                 }
            }




            while(true)
            {
                 if (GetAsyncKeyState(VK_UP) != 0)
                 {
                        pointer -= 1;
                        if (pointer == -1)
                        {
                           pointer = 1;
                        }
                        break;
                 }
                 else if (GetAsyncKeyState(VK_DOWN) != 0)
                 {
                        pointer += 1;
                        if (pointer == 2)
                        {
                           pointer = 0;
                        }
                        break;
                 }
                 else if (GetAsyncKeyState(VK_RETURN) != 0)
                 {
                        switch (pointer)
                        {
                               case 0:
                               {
                                      printf("\n\n");
                                      getStudent();
                               } break;
                               case 1:
                               {
                                      printf("\n\n");
                                      getHeader();
                                      readToFile();
                                      Sleep(5000);
                               } break;         
                        }
                        break;
                 }
            } Sleep(150);
    }
 }


 void getHeader()
 {
 printf("%-10s","ID");
 printf("%-10s","FirstName");
 printf("%-10s","LastName");
 printf("%-20s","MiddleInitial");
 printf("%-15s","Course");
 printf("%-15s","Year");


 printf("%-10s","-------");
 printf("%-10s","---------");
 printf("%-10s","--------");
 printf("%-10s","----------");
 printf("%-10s","-------");
 printf("%-10s","---------");
  printf("%10s","-------");
  printf("%s","          ");



 }

 void getStudent(void)
 {
  studtype stud;
 FILE * fp;
 if(( fp = fopen("sample.txt","a"))!=NULL)
     {
            system("cls");
            printf("Enter Student ID: ");
            scanf("%d",&stud.ID);
            printf("Enter FirstName: ");
            fflush(stdin);
            gets(stud.fname);
            printf("Enter LastName: ");
            fflush(stdin);
            gets(stud.lname);
            printf("Enter MI: ");
            scanf("%c",&stud.mi);
            printf("Enter Course: ");
            fflush(stdin);
            gets(stud.course);
            printf("Enter Year: ");
            scanf("%d",&stud.year);
            fwrite(&stud,sizeof(studtype),1,fp);
            fclose(fp);
      }



  }
 void readToFile(void)
 {
 studtype stud;
 FILE * fp;
 if(( fp = fopen("sample.txt","r"))!=NULL)
  {
        while(fread(&stud,sizeof(studtype),1,fp))
        {
                printf("%-10d",stud.ID);
                printf("%15s",stud.fname);
                printf("%10s",stud.lname);
                printf("%10c",stud.mi);
                printf("%15s",stud.course);
                printf("%10d",stud.year);
                printf("%10s","");
        }
        fclose(fp);
  }


 }

问题出在哪里？

Answer 1

一般来说，混合使用 C++ 风格的流输入和输出、C 风格的 I/O、conio 风格的键盘 I/O 和系统调用屏幕 clr 并不是一个好主意。四种不同的东西不能保证一起发挥良好的作用。