java - 无法同步 Android 乘法应用程序上问题的答案

Question

我的简单 Android 应用程序有问题。当我启动它时，问题似乎比我作为输入输入的答案领先一步。例如，如果问题是 3x3 = ?，它将只接受下一个问题的正确答案。所以我在当前问题中给出的任何答案都将永远是错误的。我通过连续输入相同的答案来测试这一点。 任何指示将不胜感激。我希望这是有道理的!

public class MainActivity extends AppCompatActivity {

    int value3;
    int answer;
    EditText answer_field;

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

        final ImageView leftNumber = findViewById(R.id.left_number);

        final ImageView rightNumber = findViewById(R.id.right_number);

        Button myButton = findViewById(R.id.answer_button);

        final int[] numberArray = new int[]{
                R.drawable.number_0,
                R.drawable.number1,
                R.drawable.number2,
                R.drawable.number3,
                R.drawable.number4,
                R.drawable.number5,
                R.drawable.number6,
                R.drawable.number7,
                R.drawable.number8,
                R.drawable.number9,
        };
        leftNumber.setImageResource(numberArray[0]);
        rightNumber.setImageResource(numberArray[0]);


        myButton.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {


                // Create a random number generator
                Random randomNumberGenerator = new Random();


                int value1 = randomNumberGenerator.nextInt(10);




                leftNumber.setImageResource(numberArray[value1]);

                // Create a new random number
                int value2 = randomNumberGenerator.nextInt(10);

                // Set the right dice image using an image from the diceArray.
                rightNumber.setImageResource(numberArray[value2]);
                answer_field = findViewById(R.id.answer_field);
                answer = valueOf(answer_field.getText().toString());
                value3 = value1 * value2;
                if(value3 == answer) {

                    showToast("Correct");
                }

            }

        });

    }


    public void showToast(String text){
        Toast.makeText(MainActivity.this, text, Toast.LENGTH_LONG).show();
    }

}

谢谢!

Answer 1

您在点击答案按钮时生成值，这意味着每次用户点击答案按钮时，要相乘的值都会随机设置(或重置)；将生成值的逻辑放在 onclick 之外，因此当用户单击它时只会进行比较，有点像这样:

[...]

    leftNumber.setImageResource(numberArray[0]);
    rightNumber.setImageResource(numberArray[0]);

     // Create a random number generator
     Random randomNumberGenerator = new Random();

     int value1 = randomNumberGenerator.nextInt(10);

     leftNumber.setImageResource(numberArray[value1]);

     // Create a new random number
     int value2 = randomNumberGenerator.nextInt(10);

     // Set the right dice image using an image from the diceArray.
     rightNumber.setImageResource(numberArray[value2]);
     answer_field = findViewById(R.id.answer_field);

        myButton.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
              answer = valueOf(answer_field.getText().toString());
                value3 = value1 * value2;
                if(value3 == answer) {
                    showToast("Correct");
                }
            }
        });

[...]