Question

我的Android应用程序有一个奇怪的问题。运行上述方法时answer_str = "When the activity is destroyed"和questCHoiceStr = "When the user leave the activity."。但if条件返回true表示真的很奇怪！

private QuestionChoice getSelectedQuestionChoice()
{
    int radioButtonID = radioButtonGroup.getCheckedRadioButtonId();
    RadioButton radioButton = (RadioButton)radioButtonGroup.findViewById(radioButtonID);
    if (radioButton != null)
    {
        String answer_str = radioButton.getText().toString();
        for (int i = 0; i < map.get(current_question).size(); i++)
        {
            List<QuestionChoice> questionChoiceList = map.get(current_question);
            QuestionChoice questionChoice = questionChoiceList.get(i);
            String questCHoiceStr = questionChoice.choice;
            if (questCHoiceStr.equals(answer_str));
            {
                return map.get(current_question).get(i);
            }
        }
        return null;
    }
    else
    return null;
}

我尝试添加trim()但没有改变...... 我的程序中使用的字符串是来自xml文件的字符串（也许它与此有关）。你知道是什么原因引起的吗？ THX

Answer 1

当你添加;时，就会立即关闭。

if (questCHoiceStr.equals(answer_str)); <--

当你立即关闭它时，你的if是不是真的有效。

应该是

if (questCHoiceStr.equals(answer_str))

您当前的代码等于

if (questCHoiceStr.equals(answer_str)){

}
{
     return map.get(current_question).get(i);
}

为了避免这些问题，我强迫我的朋友始终使用{}：

Answer 2

尝试删除if语句中的分号。分号标记if语句的结尾，因此大括号{}之间的下一个块只是将始终运行的代码。

if (questCHoiceStr.equals(answer_str))
{
    return map.get(current_question).get(i);
}

Answer 3

private QuestionChoice getSelectedQuestionChoice()
    {
        int radioButtonID = radioButtonGroup.getCheckedRadioButtonId();
        RadioButton radioButton = (RadioButton)radioButtonGroup.findViewById(radioButtonID);
        if (radioButton != null)
        {
            String answer_str = radioButton.getText().toString();
            for (int i = 0; i < map.get(current_question).size(); i++)
            {
                List<QuestionChoice> questionChoiceList = map.get(current_question);
                QuestionChoice questionChoice = questionChoiceList.get(i);
                String questCHoiceStr = questionChoice.choice;
                **if (questCHoiceStr.equals(answer_str))**
                {
                    return map.get(current_question).get(i);
                }
            }
            return null;
        }
        else
        return null;
    }

equals（）使用字符串返回true而两个变量不返回true

3 个答案: