Question

我正在尝试将文本颜色设置为红色，以及所有单选按钮，但是来自我拥有的所有广播组。何时使用answer[i].setTextColor(Color.RED);，这仅适用于最后一个广播组。

如果尝试使用radioGroup[i].getChildAt(j).setBackgroundColor(Color.GREEN);将背景颜色更改为所有单选按钮，则会收到以下错误：Attempt to invoke virtual method 'android.view.View android.widget.RadioGroup.getChildAt(int)' on a null object reference。

我该如何解决这个问题？有没有其他方法可以做到这一点？
这是我的代码：

    radioGroup = new RadioGroup[4];
    answer = new RadioButton[4];
    for (Question qn : questions) {
        int i = 0;
        radioGroup[i] = new RadioGroup(this);
        radioGroup[i].setOrientation(RadioGroup.VERTICAL);
        int j = 0;
        for (Answer an : answers) {
            if (qn.getID() == an.getQuestion_id_answer()) {
                String answers_log = " " + an.getAnswer();
                answer[j] = new RadioButton(this);
                answer[j].setText(answers_log);
                radioGroup[i].addView(answer[j]);
                j++;
            }
        }
        linearLayout.addView(radioGroup[i]);
        i++;
    }

    finishButton = new Button(this);
    linearLayout.addView(finishButton);

    finishButton.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            for (int i = 0; i < radioGroup.length; i++) {
                for (int j = 0; j < answer.length; j++) {
                    answer[i].setTextColor(Color.RED);
                }
            }
        }
    });

谢谢！

Answer 1

<强>更新

试试这段代码：

    radioGroup = new RadioGroup[4];
    answer = new RadioButton[4];
    int i = 0;
    for (Question qn : questions) {
        radioGroup[i] = new RadioGroup(this);
        radioGroup[i].setOrientation(RadioGroup.VERTICAL);
        int j = 0;
        for (Answer an : answers) {
            if (qn.getID() == an.getQuestion_id_answer()) {
                String answers_log = " " + an.getAnswer();
                answer[j] = new RadioButton(this);
                answer[j].setText(answers_log);
                radioGroup[i].addView(answer[j]);
                j++;
            }
        }
        linearLayout.addView(radioGroup[i]);
        i++;
    }

    finishButton = new Button(this);
    linearLayout.addView(finishButton);

    finishButton.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            for (int i = 0; i < radioGroup.length; i++) {
                for (int j = 0; j < radioGroup[i].getChildCount(); j++) {
                    radioGroup[i].getChildAt(j).setBackgroundColor(Color.GREEN);
                }
            }
        }
    });

Answer 2

试试这个：

finishButton.setOnClickListener(new View.OnClickListener() {
    @Override
    public void onClick(View v) {
        for (int i = 0; i < 4; i++) {
            radioGroup[i].clearCheck();
            for (int j = 0; j < 4; j++) {
                radioGroup[i].getChildAt(j).setEnabled(true);
                ((RadioButton)radioGroup[i].getChildAt(j)).setTextColor(Color.RED);
                ((RadioButton)radioGroup[i].getChildAt(j)).setChecked(false);
            }
        }
    }
});

Answer 3

我很棒！

你只想获得4 RadioGroup和4 RadioButton？

将for(b: bs )更改为for(int i = 0;i<bs.size();i++)

    finishButton.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
        try{
            for (int i = 0; i < radioGroup.length; i++) {
                int len = radioGroup[i].getChildCount();
                for (int j = 0; j < len; j++) {
                    radioGroup[i].getChildAt(j).setBackgroundColor(
                            Color.GREEN);
                }
            }
         }catch(Throwable e){
          }

        }
    });

如何将文本颜色设置为Java中所有无线电组的所有单选按钮

3 个答案: