String.Equals不生效：C#问答控制台程序答案判断始终错误的问题

核心问题所在 #

你代码里的System.Console.ReadKey();是导致所有答案都被判错的罪魁祸首！

当你打印完问题后调用ReadKey()，它会等待用户按下任意键（包括回车键）。当用户按回车继续时，这个回车键的输入已经被ReadKey()消耗掉了，紧接着的Console.ReadLine()就只能读到一个空字符串。这就导致不管用户之后输入什么正确答案，Answer变量都是空的，用Equals和正确答案比对自然永远不匹配，程序就一直判定错误。

修复步骤 #

1. 移除多余的ReadKey() #

直接删掉这行代码，让Console.ReadLine()正常接收用户的输入：

static void Main(string[] args) { 
    //Random number generator 
    Random rnd = new Random(); 
    int randInt = rnd.Next(0, 9); 

    //Questions array Question/Answer 
    string[,] array2D = new string[10, 2] { 
        { "Mario Kart is a video game series publish by which company?", "Nintendo" }, 
        { "What was the first console video game that allowed the game to be saved?", "The Legend of Zelda" }, 
        { "The Connecticut Leather Company later became what toy company that was popular in the 1980s for its Cabbage Patch Kids and video game consoles?", "Coleco" }, 
        { "Nintendo is a consumer electronics and video game company founded in what country?", "Japan" }, 
        { "The first person shooter video game Doom was first released in what year?", "1993" }, 
        { "In what year did Nintendo release its first game console in North America?", "1985" }, 
        { "In the world of video games, what does NES stand for?", "Nintendo Entertainment System" }, 
        { "In what year was the Nintendo 64 officially released?", "1996" }, 
        { "What was the most popular video game in the year 1999?", "Doom" }, 
        { "If you have any kind of console known to mankind, what will your mother call it no matter what?", "A Nintendo" } 
    }; 

    //printing the question 
    System.Console.WriteLine(array2D[randInt, 0]); 
    // 移除这行多余的 ReadKey()
    // System.Console.ReadKey(); 

    //taking user input 
    string Answer = Console.ReadLine(); 

    //checking to see if the answer is correct 
    if (Answer.Equals(array2D[randInt, 1])) { 
        //the console exclamation for the right answer given in any scenario. 
        Console.WriteLine("Correct Answer! Good job!"); 
        Console.ReadKey(); 
    } else { 
        //the console exlamation for the incorrect answer in any given scnario 
        Console.WriteLine("Aw man! You got it wrong! Better luck next time :("); 
        Console.WriteLine("The correct answer was {0}", array2D[randInt, 1]); 
        Console.ReadKey(); 
    } 
}

2. 可选优化：忽略大小写比对 #

默认的String.Equals是区分大小写的，用户输入nintendo就会被判定错误。可以修改比对逻辑，让程序更友好：

if (string.Equals(Answer, array2D[randInt, 1], StringComparison.OrdinalIgnoreCase))

这样不管用户输入大写、小写还是混合大小写，只要内容正确就能判定为答对。

额外提示 #

如果确实想保留“看完问题按任意键再输入答案”的逻辑，可以这样处理：

System.Console.WriteLine(array2D[randInt, 0]);
System.Console.WriteLine("Press any key to enter your answer...");
System.Console.ReadKey(true); // 添加true参数，不显示按下的键
string Answer = Console.ReadLine();

ReadKey(true)不会把用户按下的键显示在控制台，之后ReadLine()就能正常接收输入了。

内容的提问来源于stack exchange，提问作者Nesox