代码不起作用

Question

我的应用程序有一个问题列表。当调用 getfirstquestion 函数时，它会随机选择一个问题，然后在 4 个按钮中的每一个上随机放置文本（其中一个是问题的答案）。

每次按下按钮时，函数 checkanswer 会验证按钮文本是否等于正确问题的正确答案。如果是，则删除当前问题，并调用 getfirstquestion() 函数来更改问题。

程序运行正常，但是当我按下正确答案按钮时没有任何反应。谁能告诉我为什么，并给我一个解决方案？我从 2 小时前开始搜索代码....

    public class startgame extends Activity implements OnClickListener{

final Random rgenerator = new Random();

List<String> questionss1 = new ArrayList<String>();
String thequestion;

public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.level1);

    questionss1.add("Who is the actual CEO at Apple?");
    questionss1.add("Who is the actual CEO at Microsoft?");
    questionss1.add("Who is the actual CEO at Google?");
    getfirstquestion();

    Button button1 = (Button)findViewById(R.id.button1);
    button1.setOnClickListener(this);

    Button button2 = (Button)findViewById(R.id.button2);
    button2.setOnClickListener(this);
    Button button3 = (Button)findViewById(R.id.button3);
    button3.setOnClickListener(this);
    Button button4 = (Button)findViewById(R.id.button4);
    button4.setOnClickListener(this);
    }
    }

public void onClick(View v) {
    // TODO Auto-generated method stub
    switch (v.getId()){
    case R.id.button1:  

        Button button1 = (Button)findViewById(R.id.button1);
        checkanswer((String) button1.getText());

    case R.id.button2:
       Button button2 = (Button)findViewById(R.id.button2);
           checkanswer((String) button2.getText());

    case R.id.button3:
        Button button3 = (Button)findViewById(R.id.button2);
    checkanswer((String) button3.getText());

    case R.id.button4:
        Button button4 = (Button)findViewById(R.id.button2);
       checkanswer((String) button4.getText());
    }
}
public int checkanswer(String buttontext) {
    if (thequestion.equals("Who is the actual CEO at Apple?") && buttontext == "Tim Cook"){
        questionss1.remove("Who is the actual CEO at Apple?");
        getfirstquestion();
    }

    if (thequestion.equals("Who is the actual CEO at Microsoft?") && buttontext  == "Steve Ballmer"){
        questionss1.remove("Who is the actual CEO at Microsoft?");
        getfirstquestion();
    }

    if (thequestion.equals("Who is the actual CEO at Google?") && buttontext == "Eric Schmidt"){
        questionss1.remove("Who is the actual CEO at Google?");
        getfirstquestion();
    }
    return 0;
}

public void getfirstquestion(){
    //create the buttons
    Button button1 = (Button)findViewById(R.id.button1);
    Button button2 = (Button)findViewById(R.id.button2);
    Button button3 = (Button)findViewById(R.id.button3);
    Button button4 = (Button)findViewById(R.id.button4);

    thequestion = questionss1.get(rgenerator.nextInt(questionss1.size()));
    TextView question = (TextView)findViewById(R.id.textView1);
    question.setText(thequestion);
    questionss1.remove(thequestion);

    if (thequestion.equals("Who is the actual CEO at Apple?")){
        List<String> questions1res = new ArrayList<String>();
        questions1res.add("Eric Schmidt");
        questions1res.add("Steven Sinofsky");
        questions1res.add("Tim Cook");
        questions1res.add("Steve Ballmer");

        button1.setText(questions1res.get(rgenerator.nextInt(questions1res.size())));
        questions1res.remove(button1.getText());
        button2.setText(questions1res.get(rgenerator.nextInt(questions1res.size())));
        questions1res.remove(button2.getText());
        button3.setText(questions1res.get(rgenerator.nextInt(questions1res.size())));
        questions1res.remove(button3.getText());
        button4.setText(questions1res.get(rgenerator.nextInt(questions1res.size())));
        questions1res.remove(button4.getText());
    }

    if (thequestion.equals("Who is the actual CEO at Microsoft?")){
        List<String> questions1res = new ArrayList<String>();
        questions1res.add("Eric Schmidt");
        questions1res.add("Steven Sinofsky");
        questions1res.add("Tim Cook");
        questions1res.add("Steve Ballmer");

        button1.setText(questions1res.get(rgenerator.nextInt(questions1res.size())));
        questions1res.remove(button1.getText());
        button2.setText(questions1res.get(rgenerator.nextInt(questions1res.size())));
        questions1res.remove(button2.getText());
        button3.setText(questions1res.get(rgenerator.nextInt(questions1res.size())));
        questions1res.remove(button3.getText());
        button4.setText(questions1res.get(rgenerator.nextInt(questions1res.size())));
        questions1res.remove(button4.getText());
    }

    if (thequestion.equals("Who is the actual CEO at Google?")){
        List<String> questions1res = new ArrayList<String>();
        questions1res.add("Eric Schmidt");
        questions1res.add("Steven Sinofsky");
        questions1res.add("Tim Cook");
        questions1res.add("Steve Ballmer");

        button1.setText(questions1res.get(rgenerator.nextInt(questions1res.size())));
        questions1res.remove(button1.getText());
        button2.setText(questions1res.get(rgenerator.nextInt(questions1res.size())));
        questions1res.remove(button2.getText());
        button3.setText(questions1res.get(rgenerator.nextInt(questions1res.size())));
        questions1res.remove(button3.getText());
        button4.setText(questions1res.get(rgenerator.nextInt(questions1res.size())));
        questions1res.remove(button4.getText());
    }
}
    }

Answer 1

在checkanswer 方法中，您应该使用equals 方法，而不是== 运算符，因为它比较引用而不是对象的内容。即应该是 buttontext.equals("Tim Cook") 等，而不是 buttontext == "Tim Cook"。

另外，再次查看您的代码，您应该在 switch 中添加 break; 语句：

switch (v.getId()){
case R.id.button1:
    Button button1 = (Button)findViewById(R.id.button1);
    checkanswer((String) button1.getText());
    break;
case R.id.button2:
    Button button2 = (Button)findViewById(R.id.button2);
    checkanswer((String) button2.getText());
    break;
case R.id.button3:
    Button button3 = (Button)findViewById(R.id.button2);
    checkanswer((String) button3.getText());
    break;
case R.id.button4:
    Button button4 = (Button)findViewById(R.id.button2);
    checkanswer((String) button4.getText());
    break;
}

Answer 2

button1.setOnClickListener(this);

此代码用于将 OnClickListener 设置为按钮。您需要在您的类中实例化一个 OnClickListener 并使用它。传入（this）将传入activity。在这种情况下，单击按钮不会执行任何操作。

类似这样的：

button1.setOnClickListener(new OnClickListener() {
    @Override
    public void onClick(View v) {
        // do your checking here
    }
};

试试看，告诉我它是如何工作的。