自定义网格视图中的问题与多个单选按钮在Android中单一选择

Question

我用radiobutton实现了一个Gridview，这是我的代码：

row_layout.xml：

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:padding="5dp" >

<ImageView
    android:id="@+id/imageView1"
    android:layout_width="50px"
    android:layout_height="50px"
    android:layout_marginRight="10px" >
</ImageView>

<RadioButton
    android:id="@+id/radio"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content" 
    android:focusable="false"
    android:focusableInTouchMode="false"/>

<TextView
    android:id="@+id/textView1"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_marginTop="5px"
    android:textSize="15px" >
</TextView>

</LinearLayout>

我的MainActivity.java文件

public class Radio extends Activity {

ArrayList<ParserCategory>mList;
DatabaseConnectionAPI mApi;
ImageAdapter mAdapter;
@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    /*** Get Images from SDCard ***/

    // gridView1
    mApi=new DatabaseConnectionAPI(getApplicationContext());
    try {
        mApi.createDataBase();
          mApi.openDataBase();
    } catch (IOException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    }

    mList=mApi.getCategoryData();
    final GridView gView1 = (GridView)findViewById(R.id.gridView1); 

    mAdapter=new ImageAdapter(Radio.this, mList);
    gView1.setAdapter(mAdapter);


    // Get Item Checked
    Button btnGetItem = (Button) findViewById(R.id.btnGetItem);
    btnGetItem.setOnClickListener(new OnClickListener() {
        public void onClick(View v) {
            int count =  gView1.getChildCount();

            System.out.println("Count "+count);
            for (int i = 0; i < count; i++) {
                ViewGroup gridChild = (ViewGroup) gView1.getChildAt(i);
                RadioButton rbtn = (RadioButton)gridChild.findViewById(R.id.radio);
                if(rbtn.isChecked())
                {
                    Log.d("Item "+String.valueOf(i), rbtn.getTag().toString());
                    System.out.println("ITEEMERM  "+String.valueOf(i)+rbtn.getTag().toString());
                    Toast.makeText(Radio.this,rbtn.getTag().toString() ,2000).show();  
                }
            }  
        }
    });

}


public class ImageAdapter extends BaseAdapter 
{
    private Context context;
    private ArrayList<ParserCategory> lis;

    public ImageAdapter(Context c, ArrayList<ParserCategory> mList) 
    {
        context = c;
        lis = mList;
    }

    public int getCount() {
        return lis.size();
    }

    public Object getItem(int position) {
        return position;
    }

    public long getItemId(int position) {
        return position;
    }

    public View getView(int position, View convertView, ViewGroup parent) {

        LayoutInflater inflater = (LayoutInflater) context
                .getSystemService(Context.LAYOUT_INFLATER_SERVICE);


            if (convertView == null) {
                convertView = inflater.inflate(R.layout.raddioshowimage, null);
            }

            TextView textView = (TextView) convertView.findViewById(R.id.textView1);
            String strPath = lis.get(position).toString();

            // Get File Name
            String fileName=lis.get(position).getCname();
            textView.setText(lis.get(position).getCname());

            ImageView imageView = (ImageView) convertView.findViewById(R.id.imageView1);
            RadioButton radiobtn = (RadioButton) convertView.findViewById(R.id.radio);
            radiobtn.setTag(fileName);

            return convertView;

    }
       } 

 }

当我运行上面的代码时，它会选择多个带有radiobutton的项目，但是当我点击一个按钮时我想要一个项目选择，所以我知道如何解决它？