java - 单击时正确生成整数

Question

关于调用函数时生成的整数，我的代码遇到了问题 - 我的代码是一个数学游戏，用户用 1 到 12 的数字回答随机算术问题，我可以这样做，但代码似乎在允许用户回答上一个问题之前生成新的随机值，这意味着用户回答屏幕上未显示的下一个问题。我认为它在我对特定行进行评论的代码中描述得更好。

public class MainActivity extends AppCompatActivity {




Random r = new Random();
int points1 = 0;


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

    int value1 = r.nextInt(12 - 1) + 1;             //1st randomized set of values
    int value2 = r.nextInt(12 - 1) + 1;             // ^
    TextView Number1 = findViewById(R.id.number1);
    Number1.setText(""+value1);                            //assigns randomized values to TextViews
    TextView Number2 = findViewById(R.id.number2);
    Number2.setText(""+value2);                            // ^^

}

public void onSubmitCheck (View view) {
    reset();                                               //When button Submit is clicked

}       //^ ^ Issue starts here when we click "submit" - the code generates new random values before checking the old ones against the mathematical expression in line 50..
        //..meaning the user is already answering to the SECOND question before even attempting the first one.

public void reset(){
    int value1 = r.nextInt(12 - 1) + 1;            //Assigns 2nd randomized values
    int value2 = r.nextInt(12 - 1) + 1;            // ^
        TextView Number1 = findViewById(R.id.number1);
        Number1.setText("" + value1);
        TextView Number2 = findViewById(R.id.number2);
        Number2.setText("" + value2);
    TextView Answer = findViewById(R.id.Answer);
    TextView displayPoints = findViewById(R.id.points);
    EditText Attempt = findViewById(R.id.Attempt);
    int userAnswer = Integer.parseInt(Attempt.getText().toString());    //compares inputted value to an answer from line 50
    if (userAnswer == value1 + value2) {                                    //LINE 50
        Answer.setText("Correct!");
        point();
        displayPoints.setText(""+ points1);

    } else {
        Answer.setText("Wrong :( Answer was: " + (value1 + value2));
    }

最后，我想要实现的是在创建(onCreate)时生成用户可以回答的值，然后在用户输入和提交后，应用程序应该生成新值并允许用户再次回答。我并不期望为我完成全部工作，而是希望能够引导我找到答案，因为我真的很想学习和理解我的问题。

我尝试了不同的方法，但我想这只是我的经验和知识阻碍了我找到解决方案 - 我是一个初学者并且自学成才。

编辑随机运算符(operator)问题；

公共(public)类 MainActivity 扩展 AppCompatActivity {

Random r = new Random();


int points1 = 0;
int value1, value2;
TextView Number1;
TextView Number2;
TextView Answer;
TextView displayPoints;
EditText Attempt;
TextView Operator;

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

    Number1 = findViewById(R.id.number1);
    Number2 = findViewById(R.id.number2);
    Answer = findViewById(R.id.Answer);
    Operator = findViewById(R.id.operator);
    displayPoints = findViewById(R.id.points);
    Attempt = findViewById(R.id.Attempt);

    value1 = r.nextInt(12 - 1) + 1;             
    value2 = r.nextInt(12 - 1) + 1;             
    Number1.setText("" + value1);                            
    Number2.setText("" + value2);

    int operator = r.nextInt(4 - 1) + 1;        //HERE
    switch (operator)
    {
        case 1: operator = '+';
            break;
        case 2: operator = '-';
            break;
        case 3: operator = '*';
            break;
        case 4: operator = '/';
            break;
    }
    Operator.setText("" + operator);
}




public void onSubmitCheck(View view) {
    reset();

}

public void reset() {


    int operator = r.nextInt(4 - 1) + 1;                   //here
    switch (operator)
    {
        case 1: operator = '+';
            break;
        case 2: operator = '-';
            break;
        case 3: operator = '*';
            break;
        case 4: operator = '/';
            break;
    }

    int userAnswer = Integer.parseInt(Attempt.getText().toString());
    if (userAnswer == value1 + operator + value2) {
        Answer.setText("Correct!");
        point();
        displayPoints.setText("" + points1);

    } else {
        Answer.setText("The answer was: " + (value1 + value2));
    }

    value1 = r.nextInt(12 - 1) + 1;             
    value2 = r.nextInt(12 - 1) + 1;            
    Number1.setText("" + value1);
    Number2.setText("" + value2);
    Operator.setText("" + Operator);

}
public void point() {
    points1 = points1 + 1;

}


public void onSubmitNext(View view) {
    reset();
}

}

Answer 1

将 value1 和 value2 设为全局值，并仅在与旧值进行比较后重置这些值。还做了一些其他的重新安排。

这可能是您的代码:

public class MainActivity extends AppCompatActivity {


Random r = new Random();
int points1 = 0;
int value1, value2;
TextView Number1;
TextView Number2;
TextView Answer;
TextView displayPoints;
EditText Attempt;

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

    Number1 = findViewById(R.id.number1);
    Number2 = findViewById(R.id.number2);
    Answer = findViewById(R.id.Answer);
    displayPoints = findViewById(R.id.points);
    Attempt = findViewById(R.id.Attempt);

    value1 = r.nextInt(12 - 1) + 1;             //1st randomized set of values
    value2 = r.nextInt(12 - 1) + 1;             // ^
    Number1.setText("" + value1);                            //assigns randomized values to textEdits
    Number2.setText("" + value2);                            // ^^

}

public void onSubmitCheck(View view) {
    reset();                                               //When button Submit is clicked

}       //^ ^ Issue starts here when we click "submit" - the code generates new random values before checking the old ones against the mathematical expression in line 50..
//..meaning the user is already answering to the SECOND question before even attempting the first one.

public void reset() {

    int userAnswer = Integer.parseInt(Attempt.getText().toString());    //compares inputted value to an answer from line 50
    if (userAnswer == value1 + value2) {                                    //LINE 50
        Answer.setText("Correct!");
        point();
        displayPoints.setText("" + points1);

    } else {
        Answer.setText("Wrong :( Answer was: " + (value1 + value2));
    }

    value1 = r.nextInt(12 - 1) + 1;            //Assigns 2nd randomized values
    value2 = r.nextInt(12 - 1) + 1;            // ^
    Number1.setText("" + value1);
    Number2.setText("" + value2);