当前上下文方法中不存在的名称

Question

我正在试图创建一个程序，它将int的方法从类中的方法拖入另一个类中。当它进入主程序时，它应该运行if语句来仅显示某些值。然而，在主程序类中，我得到错误，名称###在当前上下文中不存在。如果有人可以看看这个，并告诉我我错过了什么，这将是非常感激。我在主程序类中遇到counter，die1和die2变量的问题。

namespace DiceRoll 
{ 
    public class RollClass 
    { 
     public void RollMethodDice() 
     { 
      int die1, die2, counter; 
      // create Random number generator 
      Random rndRoll = new Random(); 

      // Loop that counts the # of rolls from 1 to 100 
      for (counter = 1; counter <= 100; counter++) 
      { 
       // Random generators for each die 
       die1 = rndRoll.Next(1, 7); 
       die2 = rndRoll.Next(1, 7); 
      } 
     } 

     public int GetDiceRoll() 
     { 
      return die1; 
      return die2; 
      return counter; 
     } 

     public int die1 { get; set; } 
     public int die2 { get; set; } 
     public int counter { get; set; }   
    } 

    class Program 
    {  
     static void Main(string[] args) 
     {     
      Console.WriteLine("Welcome to the dice rolling program."); 
      Console.WriteLine(); 
      Console.WriteLine("This program will roll dice 100 times and display the roll where doubles land."); 
      Console.WriteLine(); 
      Console.WriteLine("Rolls that were in doubles:"); 

      RollClass myRollClass = new RollClass(); 

      myRollClass.RollMethodDice(); 

      if (die1 == die2) 
      { 
       Console.WriteLine("Roll "+ counter + ": "+ die1 + " "+ die2); 
      } 
     } 

     // Key stroke is needed to close console window so results are visible 
     Console.ReadKey(); 
    } 
} 

Answer 1

你似乎宣告

public int die1 { get; set; } 
public int die2 { get; set; } 
public int counter { get; set; }   

在RollClass，而不是在Program。如果你想使用它们，通过变量名

RollClass myRollClass = new RollClass(); 
if (myRollClass.die1 == myRollClass.die2) 
{ 
    Console.WriteLine("Roll "+ myRollClass.counter + ": "+ myRollClass.die1 + " "+ myRollClass.die2); 
} 

除了之前写RollClass的实例名称使用，似乎在RollMethodDice方法，并在RollClass类是“复制”的die1, die2, counter名。这是允许的。但是，在这种情况下，默认情况下，类变量需要使用this关键字（this.die1）被称为从局部变量区分die1

而且，你所做的功能

public int GetDiceRoll() 
{ 
    return die1; //only this will be returned! 
    return die2; //will never come here 
    return counter; //will never come here 
} 

只会返回die1。如果你想返回他们三个你应该创建一个新struct或class包含三个变量

public struct DiceResult { 
    public int die1; 
    public int die2; 
    public int counter; 
} 

在那里你可以

public DiceResult diceResult { get; set; } 

更换

public int die1 { get; set; } 
public int die2 { get; set; } 
public int counter { get; set; }   

而且把像这样的功能

public DiceResult GetDiceRoll() 
{ 
    return diceResult; 
} 

并调用在Program变量这样

RollClass myRollClass = new RollClass(); 
if (myRollClass.diceResult.die1 == myRollClass.diceResult.die2) 
{ 
    Console.WriteLine("Roll "+ myRollClass.diceResult.counter + ": "+ myRollClass.diceResult.die1 + " "+ myRollClass.diceResult.die2); 
} 

希望这将帮助！

Answer 2

问题，您的变量声明

for (this.counter = 1; this.counter <= 100; this.counter++) 
     { 
      // Random generators for each die 
      this.die1 = rndRoll.Next(1, 7); 
      this.die2 = rndRoll.Next(1, 7); 
     } 

Answer 3

你的程序有几个问题。

namespace DiceRoll 
{ 
    public class RollClass 
    { 
     //int die1, die2, counter; // <-- Field of class should be defined outside method. 
            // <-- And since you used auto generated property below, these are not needed here. 
     public void RollMethodDice() 
     { 
      // create Random number generator 
      Random rndRoll = new Random(); 

      // Loop that counts the # of rolls from 1 to 100 
      for (counter = 1; counter <= 100; counter++) { 
       // Random generators for each die 
       die1 = rndRoll.Next(1, 7); 
       die2 = rndRoll.Next(1, 7); 
      } 
     } 

     public int GetDiceRoll() 
     { 
      return die1; 
      //return die2; // <-------- You cannot return multiple values in a method. 
      //return counter; // <----- Instead, an array point/reference is possible. 
     } 

     public int die1 { get; set; } 
     public int die2 { get; set; } 
     public int counter { get; set; } 
    } 

    class Program 
    { 
     static void Main(string[] args) 
     { 

      Console.WriteLine("Welcome to the dice rolling program."); 
      Console.WriteLine(); 
      Console.WriteLine("This program will roll dice 100 times and display the roll where doubles land."); 
      Console.WriteLine(); 
      Console.WriteLine("Rolls that were in doubles:"); 

      RollClass myRollClass = new RollClass(); 

      myRollClass.RollMethodDice(); 

      if (myRollClass.die1 == myRollClass.die2) // <--- You need use your class instance to access the property. 
      { 
       Console.WriteLine("Roll " + myRollClass.counter + ": " + myRollClass.die1 + " " + myRollClass.die2); 
      } 
      // Key stroke is needed to close console window so results are visible 
      Console.ReadKey(); // <--------- Method call should be stay inside a method, not a class. 
     } 
    } 
} 

总而言之，你确实需要阅读一些基本的面向对象的书。例如Head First C#。并且​​也是有帮助的。