androidstudio随机数加减乘除

以下是在 Android Studio 中实现随机数加减乘除的代码示例：

import java.util.Random;

public class MainActivity extends AppCompatActivity {

    private TextView mQuestionTextView;
    private EditText mAnswerEditText;
    private Button mSubmitButton;
    private int mNum1, mNum2, mOperator, mAnswer;

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

        mQuestionTextView = findViewById(R.id.question_text_view);
        mAnswerEditText = findViewById(R.id.answer_edit_text);
        mSubmitButton = findViewById(R.id.submit_button);

        generateQuestion();

        mSubmitButton.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                String answerString = mAnswerEditText.getText().toString().trim();
                if (!answerString.isEmpty()) {
                    int answer = Integer.parseInt(answerString);
                    if (answer == mAnswer) {
                        Toast.makeText(MainActivity.this, "答案正确！", Toast.LENGTH_SHORT).show();
                        generateQuestion();
                    } else {
                        Toast.makeText(MainActivity.this, "答案错误！", Toast.LENGTH_SHORT).show();
                    }
                }
            }
        });
    }

    private void generateQuestion() {
        Random random = new Random();
        mNum1 = random.nextInt(100);
        mNum2 = random.nextInt(100);
        mOperator = random.nextInt(4);

        switch (mOperator) {
            case 0:
                mAnswer = mNum1 + mNum2;
                mQuestionTextView.setText(mNum1 + " + " + mNum2 + " = ");
                break;
            case 1:
                mAnswer = mNum1 - mNum2;
                mQuestionTextView.setText(mNum1 + " - " + mNum2 + " = ");
                break;
            case 2:
                mAnswer = mNum1 * mNum2;
                mQuestionTextView.setText(mNum1 + " × " + mNum2 + " = ");
                break;
            case 3:
                mAnswer = mNum1 / mNum2;
                mQuestionTextView.setText(mNum1 + " ÷ " + mNum2 + " = ");
                break;
        }

        mAnswerEditText.setText("");
    }
}

该示例中，我们使用了 `Random` 类来生成随机数，使用了 `switch` 语句来判断运算符并生成对应的问题，用户输入答案后判断是否正确并生成下一个问题。注意，为了简单起见，该示例没有对除数为 0 的情况进行处理，实际应用中需要根据具体需求进行处理。