选择一个单选按钮，当我回到这个活动时，选择仍然存在？

Question

自定义列表和包含单选按钮，我想选择一个单选按钮，它的工作原理。但我想保存我选择的那个raidbutton。 我使用sharedpreference，但我无法做到这一点。我知道sharedpreference是在android中节省价值的好方法。 对不起英文不好。 请帮我。

public class rowadapter extends ArrayAdapter<String> { 

private final Activity context; 
int layoutResourceId;  
private final String[] web; 
private final Integer[] imageId; 
int selectedPosition = -1; 
SharedPreferences sharedPref; 

public rowadapter(Activity context,String[] web, Integer[] imageId) { 
    super(context,R.layout.item_listview, web); 
    this.context = context; 
    this.web = web; 
    this.imageId = imageId; 
    sharedPref = context.getSharedPreferences("position",Context.MODE_PRIVATE); 
} 

public View getView(final int position, View row, ViewGroup parent) 
{ 
    LayoutInflater inflater = ((Activity)context).getLayoutInflater(); 
    backgroundholder holder = null; 
    View rowView=row; 

     rowView= inflater.inflate(R.layout.item_listview, null, true); 

     TextView txtTitle = (TextView) rowView.findViewById(R.id.txt); 
     ImageView imageView = (ImageView) rowView.findViewById(R.id.img); 
     txtTitle.setText(web[position]); 
     imageView.setImageResource(imageId[position]); 



     holder = new backgroundholder();  
     holder.radiobutton = (RadioButton)rowView.findViewById(R.id.radiobutton); 
     holder.radiobutton.setChecked(position == selectedPosition); 
     holder.radiobutton.setTag(position); 
     int checkedpos=sharedPref.getInt("poistion",-1); 
     if(checkedpos==position) 
     { 
      holder.radiobutton.setChecked(true); 
     } 
     holder.radiobutton.setOnClickListener(new View.OnClickListener() { 

     public void onClick(View view) 
       { 
        selectedPosition = (Integer)view.getTag(); 
        RadioButton radio = (RadioButton)view; 
        if(radio.isChecked()) 
        { 
        Editor editor=sharedPref.edit(); 
        editor.putInt("position", selectedPosition); 
        editor.commit(); 
        } 

        notifyDataSetInvalidated(); 
       } 
      });   
    return rowView; 
static class backgroundholder 
{ 

    RadioButton radiobutton; 
} 

Answer 1

它看起来像一个拼写错误，你写的：

int checkedpos=sharedPref.getInt("poistion",-1); 

，但它应该是：

int checkedpos=sharedPref.getInt("position",-1); 

出于这个原因，我通常喜欢用一个常数，所以你做一个实例变量，如：

public static final String POSITION = "position"; 

然后访问像这样的值：

int checkedpos = sharedPref.getInt(POSITION, -1); 
///... 
editor.putInt(POSITION, selectedPosition); 

这将更容易发现拼写错误。