c#-控制台应用程序-解决用户在没有任何数字的情况下按enter键时出现的错误

标题是有点混乱，关于得到什么我想要在那里，这是我第一次在这里

基本上，我已将字符串转换为int：

string _val = Console.ReadLine();
tempScoreToWin = Convert.ToInt32(_val);

我想知道的是，当用户a在没有输入值的情况下按enter键时，会发生错误，应用程序将结束

我怎样才能避开这件事

这是我的全部代码：

while (true)
{                                                                                                               //This will allow the player to manually change the score.
    //------------------------------------------------------------------------------------------
    string _val = "";
    ConsoleKeyInfo key;
    do
    {
        key = Console.ReadKey(true);
        if (key.Key != ConsoleKey.Backspace)
        {
            double val = 0;
            bool _x = double.TryParse(key.KeyChar.ToString(), out val);
            if (_x)
            {
                _val += key.KeyChar;
                Console.Write(key.KeyChar);
            }
        }
        else
        {
            if (key.Key == ConsoleKey.Backspace && _val.Length > 0)
            {
                _val = _val.Substring(0, (_val.Length - 1));
                Console.Write("\b \b");
            }
        }
    }

    while (key.Key != ConsoleKey.Enter);

    Console.WriteLine();

    //-----------------------------------------------------------------

    tempScoreToWin = Convert.ToInt32(_val);                                           // Converting the users input (Console.ReadLine()) into an integer.

    if (tempScoreToWin > 0)                                                                         // If the users input is higher than zero ... 
    {
        scoreToWin = tempScoreToWin;                                                                // Reset the scoreToWin variable with the value of tempScoreToWin.
        Console.WriteLine("The score has been set to {0}.", scoreToWin);                            // Let the user know that the score has been changed successfully.
        break;                                                                                      // Break out of the while loop.
    }

    else
    {                                                                                               // If the player has not put a correct integer in ...
        Console.WriteLine("The score has been set at a default of {0}.", scoreToWin);               // then the score will be set to the default value of scoreToWin
        break;                                                                                      // Break out of the while loop.
    }      
}
Console.ReadLine();

Console.Clear(); 

//-----------------------------------------------------------------

---

干杯

使用

TryParse

可以将字符串解析为整数，同时检查是否成功

if(int.TryParse(_val, out tempScoreToWin)
{
    //Parse succeeded
}
else
{
    //Parse failed
}

---

太棒了！这很管用，赞德先生。非常感谢你们的快速回答。我真的很感激：）

---

看看

Int32.TryParse

方法。你想做什么呢？编辑器中还有一个类似

{}

的按钮，允许你将文章的部分标记为代码。我会编辑代码块来整理它们，但是你现在看起来像是在积极地编辑你的帖子，所以不想意外地丢失你正在做的任何更改。嗨，弹出一条无效消息或其他什么，告诉玩家再次输入一个数字。。。还有，我如何让我的代码正确地显示在这里？你为什么要自己处理退格？只需使用

Console.Readline

然后使用

TryParse

。

if (int.TryParse(_val, out tempScoreToWin))
                {
                    if (tempScoreToWin > 0)                                                                         // If the users input is higher than zero ... 
                    {
                        scoreToWin = tempScoreToWin;                                                                // Reset the scoreToWin variable with the value of tempScoreToWin.
                        Console.WriteLine("The score has been set to {0}.", scoreToWin);                            // Let the user know that the score has been changed successfully.
                        break;                                                                                      // Break out of the while loop.
                    }

                    else
                    {                                                                                               // If the player has not put a correct integer in ...
                        Console.WriteLine("The score has been set at a default of {0}.", scoreToWin);               // then the score will be set to the default value of scoreToWin
                        break;                                                                                      // Break out of the while loop.
                    }
                }
                else
                {
                    //Parse failed
                }