Java 我如何修复错误；从静态内容引用的非静态变量“；？

我在《编程入门》（java）课程中完成了这个项目。它应该创造一个弦乐器使用的方法，并发挥乐器等。。我已经在C#中完成过这个项目一次，但不知出于什么原因，我似乎无法让它在java中工作。我一直收到一个错误，“非静态变量不能从静态内容引用。我在这里搜索了，到目前为止，没有任何解决方案对我有效。请帮助。谢谢

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您也必须将内部类声明为静态的。否则它是非静态的（您可以从非静态内部类访问外部this指针）.

查看右侧的所有链接：）欢迎使用SO。请先搜索您的问题，然后再发布一个新问题。前几天我回答了一个与此完全相同的问题。看看这些链接是否有帮助，我就不需要问我的问题了。。。。

package egreenhornfinal;
import java.util.Scanner;
/**
 *
 * @author Eddie
 */
 public class EGreenhornFinal {


class Guitar
{


    boolean isTuned; //Guitar starts off not tuned
    boolean isPlaying; //Guitar is not playing at start
    boolean isBroken; //Guitar has broken a string
    boolean isFixed; //Broken String has been fixed
    boolean isNotPlaying; //Guitar has stopped playing
    boolean songOver; //The song is over now.

    //array for Guitar strings
    char[] GuitarStrings = { 'e', 'A', 'D', 'G', 'B', 'E' };
    private int numberofStrings = 6;

    //default Guitar object
    public Guitar()
    {
        isTuned = false;
        isPlaying = false;
        isBroken = false;
        isFixed = false;
        isNotPlaying = false;
        songOver = false;

        System.out.println("The Guitar is not playing, and it is not tuned. All Strings are intact.\n");
        }
    public Guitar(boolean T, boolean P)
    {
        isTuned = T;
        isPlaying = P;
    }
    public boolean playGuitar()
    {
        System.out.println("The Guitar is playing!\n");
        return isPlaying = true;
    }
    public boolean stopPlaying()
    {
        System.out.println("The Guitar has stopped playing.\n");
        return isNotPlaying = true;
    }
    public boolean tuneGuitar()
    {
        System.out.println("The Guitar is being tuned!\n");
        return isTuned = true;
    }
    public boolean brokenString()
    {
        System.out.println("One of the strings was too tight, it has broken!\n");
        return isBroken = true;
    }
    public boolean fixedString()
    {
        System.out.println("The broken string has been fixed, the guitar is now playing again.\n");
        return isFixed = true;
    }
    public boolean EndOfSong()
    {
        System.out.println("The Guitar has stopped playing because the song is over.\n");
        return songOver = true;
    }
}

/**
 *
 * @param args
 */
public static void main(String[] args)
    {

        String WantToPlay = "Y";
        do
        {


            Guitar MyGuitar = new Guitar();
            //Error-- Non static variable being referenced from static content??


            boolean varIsTuned = false;
            varIsTuned = MyGuitar.tuneGuitar();

            boolean varIsPlaying = false;
            varIsPlaying = MyGuitar.playGuitar();

            boolean varIsNotPlaying = true;
            varIsNotPlaying = MyGuitar.stopPlaying();

            boolean varIsBroken = false;
            varIsBroken = MyGuitar.brokenString();

            boolean varIsFixed = false;
            varIsFixed = MyGuitar.fixedString();

            boolean varsongOver = false;
            varsongOver = MyGuitar.EndOfSong();

         System.out.println("Would you like to play the Guitar again? (enter Y for yes, and N for no)");
         Scanner inUsr = new Scanner(System.in);
         WantToPlay = inUsr.nextLine();



        }


        while (WantToPlay == "Y");
        }

}


`