Question

我正在使用Android Studio构建一个简单的应用程序;这是我的相关代码：

import java.util.Random;
public class MainActivity extends AppCompatActivity
{
    @Override
    protected void onCreate(Bundle savedInstanceState)
    {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
    }

    Random r = new Random();
    int num = r.nextInt(1000);
    EditText e = (EditText) findViewById(R.id.enterText);
    int userNum = Integer.parseInt(e.getText().toString());
    TextView info = (TextView) findViewById(R.id.userInfo);

    private void compare()
    {
        if(userNum > num)
        {
            info.setText("Your number is too high!");
        }
        else if(userNum < num)
        {
            info.setText("Your number is too low!");
        }
        userNum = Integer.parseInt(e.getText().toString());
    }

    while(userNum != num)
    {
        compare();
    }
}

我不知道为什么，但是在第37行，它说：

Unknown class: 'userNum'
Unknown class: 'num'
Unexpected token

这可能非常简单，但我似乎无法弄明白。

Answer 1

请尝试以下代码，

import java.util.Random;


    public class Sample extends AppCompatActivity {

        private int userNum;
        private int num;
        private EditText e;
        private TextView info;

        @Override
        protected void onCreate(Bundle savedInstanceState) {
            super.onCreate(savedInstanceState);
            setContentView(R.layout.activity_main);

            Random r = new Random();
            num = r.nextInt(1000);
            e = (EditText) findViewById(R.id.enterText);
            userNum = Integer.parseInt(e.getText().toString());
            info = (TextView) findViewById(R.id.userInfo);

        }

        private void compare() {
            if (userNum > num) {
                info.setText("Your number is too high!");
            } else if (userNum < num) {
                info.setText("Your number is too low!");
            }
            userNum = Integer.parseInt(e.getText().toString());

            while (userNum != num) {
                compare();
            }
        }
    }

Answer 2

尝试：

private void compare()
{

Random r = new Random();
int num = r.nextInt(1000);
EditText e = (EditText) findViewById(R.id.enterText);
int userNum = Integer.parseInt(e.getText().toString());
TextView info = (TextView) findViewById(R.id.userInfo);


    if(userNum > num)
    {
        info.setText("Your number is too high!");
    }
    else if(userNum < num)
    {
        info.setText("Your number is too low!");
    }
    userNum = Integer.parseInt(e.getText().toString());
}

while(userNum != num)
{
    compare();
}

找不到变量

2 个答案: