在Java中的Switch語句中更改String的值

Question

我正在嘗試在Android的switch語句中更改String數據類型的值。 而且該String是在聲明switch語句的同一方法內聲明的，當用戶單擊單選按鈕時，我需要更改String的值 。

public void CreateQuestion(View view) {

    String questionType = new String();
    RadioGroup questionTypeRadioGroup = (RadioGroup) findViewById(R.id.questionTypeRadioGroup);
    questionTypeRadioGroup.setOnCheckedChangeListener(new RadioGroup.OnCheckedChangeListener() {
        @Override
        public void onCheckedChanged(RadioGroup group, @IdRes int checkedId) {
            switch (checkedId) {
                case R.id.true_false:
                    questionType = "True/False";
                    break;

                case R.id.mcqs:
                    questionType = "MCQs";
                    break;
            }
        }
    });
}

Answer 1

你應該全局聲明你的字符串

public class ExampleActivity extends AppCompatActivity {
    public String questionType;

    ....

    public void CreateQuestion(View view) {
         questionType = "";
         questionTypeRadioGroup.setOnCheckedChangeListener(new RadioGroup.OnCheckedChangeListener() {
         @Override
         public void onCheckedChanged(RadioGroup group, @IdRes int checkedId) {
              switch (checkedId) {
                     case R.id.true_false:
                          questionType = "True/False";
                          break;

                      case R.id.mcqs:
                          questionType = "MCQs";
                          break;
                    }
                }
            });
        }

    ....

}