getline（）可以跳過不帶用戶輸入嗎？

Question

編輯

的問題是，我是在我的程序的另一點使用cin >>，因此出現了在流緩存一個換行符。

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所以主要的問題是關於getline（），但爲了把它放到透視中，你必須先看到我的代碼。出於某種奇怪的原因，當我運行我的程序時，它首次在整個循環中運行得非常好。但第二次它跳過了我的getline(cin, inputMenu)陳述。是的，我知道這是一個非常基本的程序，我知道沒有其他錯誤，因爲我已經從字面上測試了它的所有其他方面。有沒有我不知道的getline()？

while (1) 
    { 
     // Reset the input each loop 
     inputMenu = "ABC"; 

     // Menu 
     cout << "Menu\n P (Purchase)\n S (Shut down)" << "\n\n You decide: "; 

     /* I put this if statement as a test, to make sure that it always runs getline. 
     But for some odd reason when I run it I get this (see run below)*/ 
     if(1) 
     getline(cin, inputMenu); 

     //Blah blah all the other stuff if they enter a P or S. (Not an infinite loop) 

     cout << "\nYou just earned " << inputYogurt << " stamps!" 
      << " Bringing your grand total to " << numStamps << "!\n" << endl; 
     } 
    } 


---------------------- Run -------------------- 
Menu 
    P (Purchase) 
    S (Shut down) 

    You decide: p 

How many yogurts would you like to buy? 3 

You just earned 3 stamps! Bringing your grand total to 3! 


Menu 
    P (Purchase) 
    S (Shut down) 

    You decide: Menu  <<<<<<<<<<<<<<<<<<<<<<<<<< Thats my error 
    P (Purchase) 
    S (Shut down) 

    You decide: 

------------------------------------------------------- 

它跳過getline（）語句，只是再次運行循環。也許我不太瞭解getline（），因爲很明顯這似乎是問題所在。我認爲，當你使用getline時，它必須等待用戶輸入，我錯了嗎？

Answer 1

它有時會發生。要處理的唯一方法是在cin.getline()之前撥打cin.get()。在cin.getline()之前有另一種方法調用cin.flush()，但它可能不起作用。

while (1) 
    { 
     // Reset the input each loop 
     inputMenu = "ABC"; 

     // Menu 
     cout << "Menu\n P (Purchase)\n S (Shut down)" << "\n\n You decide: "; 

     /* I put this if statement as a test, to make sure that it always runs getline. 
     But for some odd reason when I run it I get this (see run below)*/ 


     cin.get(); // add extra input 
     getline(cin, inputMenu); 

     //Blah blah all the other stuff if they enter a P or S. 

     cout << "\nYou just earned " << inputYogurt << " stamps!" 
      << " Bringing your grand total to " << numStamps << "!\n" << endl; 
     } 
    } 

或嘗試使用

cin.ignore(1000, '\n'); 

getline(cin, inputMenu);