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Question

我在listview中有一个网格格式的单选按钮，我试图获取相对于行和列的radiobutton的值，但在Toast中获取空值。为什么呢？

代码：

holder.group.setOnCheckedChangeListener(new RadioGroup.OnCheckedChangeListener()
                {
                    public void onCheckedChanged(RadioGroup group, int checkedId) {
                        // checkedId is the RadioButton selected
                        //RadioButton rb=(RadioButton) findViewById(checkedId);
                        //Toast.makeText(context, rb.getText(), Toast.LENGTH_SHORT).show();

                        for (int i = 0; i < group.getChildCount(); i++) {
                            btn = (RadioButton) group.getChildAt(i);
                            int t = group.getId();
                            System.out.println(t);

                            if (btn.getId() == checkedId) {
                                text1 = btn.getText().toString();
                                Toast.makeText(context, "You selected : " + text1, Toast.LENGTH_SHORT).show();
                                return;
                            }
                        }

                    }
                });

完整代码：

RadioGroupAdapter.java

public class RadioGroupAdapter extends ArrayAdapter<Option> {

    Context context;
    int layoutResourceId;
    Option data[] = null;
    private RadioButton btn;
    private String text1;

    public RadioGroupAdapter(Context context, int layoutResourceId,
            Option[] data) {
        super(context, layoutResourceId, data);
        this.layoutResourceId = layoutResourceId;
        this.context = context;
        this.data = data;
    }

    @Override
    public View getView(int position, View convertView, ViewGroup parent) {
        View row = convertView;
        MatrixHolder holder = null;

        if (row == null) {
            LayoutInflater inflater = ((Activity) context).getLayoutInflater();
            row = inflater.inflate(layoutResourceId, parent, false);

            holder = new MatrixHolder();
            holder.txtTitle = (TextView) row.findViewById(R.id.heading);
            holder.group = (RadioGroup) row.findViewById(R.id.radio_group1);
            final RadioButton[] rb = new RadioButton[3];
            for(int i=0; i<3; i++){
                rb[i]  = new RadioButton(context);
                //rb[i].setButtonDrawable(R.drawable.single_radio_chice);
                rb[i].setId(i);
                RadioGroup.LayoutParams params = new RadioGroup.LayoutParams(0, LayoutParams.WRAP_CONTENT);
                params.weight=1.0f;
                params.setMargins(5, 0, 5, 10);
                holder.group.addView(rb[i],params);                             //the RadioButtons are added to the radioGroup instead of the layout

                holder.group.setOnCheckedChangeListener(new RadioGroup.OnCheckedChangeListener()
                {
                    public void onCheckedChanged(RadioGroup group, int checkedId) {
                        // checkedId is the RadioButton selected
                        //RadioButton rb=(RadioButton) findViewById(checkedId);
                        //Toast.makeText(context, rb.getText(), Toast.LENGTH_SHORT).show();

                        for (int i = 0; i < group.getChildCount(); i++) {
                            btn = (RadioButton) group.getChildAt(i);
                            int t = group.getId();
                            System.out.println(t);

                            if (btn.getId() == checkedId) {
                                text1 = btn.getText().toString();
                                Toast.makeText(context, "You selected : " + text1, Toast.LENGTH_SHORT).show();
                                return;
                            }
                        }

                    }
                });

            }

            row.setTag(holder);
        } else {
            holder = (MatrixHolder) row.getTag();
        }



        Option option = data[position];
        holder.txtTitle.setText(option.title);
        return row;
    }

    static class MatrixHolder {
        TextView txtTitle;
        RadioGroup group;
        int position;
    }
}

MainActivity.java

public class MainActivity extends Activity {

     private ListView listView1;
        @Override
        public void onCreate(Bundle savedInstanceState) {
            super.onCreate(savedInstanceState);
            setContentView(R.layout.activity_main);

            Option weather_data[] = new Option[]
                    {
                        new Option("Heading1"),
                        new Option("Heading2"),
                        new Option("Heading3"),
                        new Option("Heading4"),
                        new Option("Heading5"),
                        new Option("Heading6"),
                        new Option("Heading7"),
                        new Option("Heading8"),
                        new Option("Heading9"),
                        new Option("Heading10"),
                        new Option("Heading11")

                    };
            RadioGroupAdapter adapter = new RadioGroupAdapter(this, 
                            R.layout.listitem, weather_data);
                    listView1 = (ListView)findViewById(R.id.list);
                    listView1.setAdapter(adapter);
        }

        @Override
        public boolean onCreateOptionsMenu(Menu menu) {
            getMenuInflater().inflate(R.menu.activity_main, menu);
            return true;
        }

    }

Option.java

public class Option {
     public String title;
        public Option(){
            super();
        }

        public Option( String title) {
            super();
            this.title = title;
        }
    }

Answer 1

我知道你的错误。 看看这个

text1 = btn.getText().toString();
Toast.makeText(context, "You selected : " + text1,Toast.LENGTH_SHORT).show();

你想从btn.getText（）。toString获取文本。但是btn没有任何数据，所以你无法从中获取文字。

也许我知道你的尝试，你想得到被检查的身份证明，对吗？ 你应该把它改成

text1 = btn.getId().toString();

希望能帮到你

Answer 2

您的单选按钮没有设置文本。这就是当您从单选按钮执行getText()时它变为空的原因。

因此，通过调用btn.setText("yes")为您的单选按钮设置一些值，并检索该值以识别其状态被检查的单选按钮。