Android利用GridView实现单选效果

1.实现如图所示的单选效果

由于Android提供的单选按钮radiobutton只能单行或单列显示，且样式并不美观，故可用GridView进行改造，实现单选效果，而要实现这样的效果重点就在GridView的适配器这块了。

首先是GridView的item的XML：

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
   android:orientation="vertical"
   android:layout_width="match_parent"
   android:layout_height="match_parent">
<RelativeLayout
 android:id="@+id/options"
 android:layout_width="match_parent"
 android:layout_height="143dp">
 <ImageView
  android:id="@+id/imageView"
  android:layout_width="65dp"
  android:layout_height="65dp"/>
 <TextView
  android:id="@+id/textView"
  android:layout_width="wrap_content"
  android:layout_height="wrap_content"
  android:layout_centerInParent="true"
  android:text="通讯录"/>
</RelativeLayout>
</LinearLayout>

里边很简单，就只用来放显示选中效果的imageView和文字的textView

接下来是适配器：

public class GridViewRadioAdapter extends BaseAdapter {
private Context mContext;
private int lastPosition = -1;   //记录上一次选中的图片位置，默认不选中
private String[] str = null;    //放问题内容文字的数组

public GridViewRadioAdapter(Context mContext) {
 this.mContext = mContext;
}

public void setStr(String[] str){  //在activity中调用此方法传入问题的数组
 this.str = str;
}

public void setSelection(int position) { //在activity中GridView的onItemClickListener中调用此方法，来设置选中位置
 lastPosition = position;
}

@Override
public int getCount() {
 return str.length;
}

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

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

@Override
public View getView(int position, View convertView, ViewGroup parent) {
 ViewHolder viewHolder = null;
 if (convertView == null){
  viewHolder = new ViewHolder();
  convertView = LayoutInflater.from(mContext).inflate(R.layout.adapter_gridview_radio_item, null);
  viewHolder.textView = (TextView) convertView.findViewById(R.id.textView);
  viewHolder.imageView = (ImageView) convertView.findViewById(R.id.imageView);
  viewHolder.relativeLayout = (RelativeLayout) convertView.findViewById(R.id.options);
  convertView.setTag(viewHolder);
 }else {
  viewHolder = (ViewHolder) convertView.getTag();
 }
 viewHolder.textView.setText(str[position]);
 if (lastPosition == position){ //判断是否为选中项，选中项与非选中项设置不同的样式
  switch (position){  //选中状态下设置样式
   case 0:
    viewHolder.imageView.setBackgroundResource(R.drawable.option_a_checked);
    break;
   case 1:
    viewHolder.imageView.setBackgroundResource(R.drawable.option_b_checked);
    break;
   case 2:
    viewHolder.imageView.setBackgroundResource(R.drawable.option_c_checked);
    break;
   case 3:
    viewHolder.imageView.setBackgroundResource(R.drawable.option_d_checked);
    break;
  }
  viewHolder.relativeLayout.setBackgroundResource(R.drawable.shape_rect_orange);
 }else {  //非选中状态下设置样式
  switch (position){
   case 0:
    viewHolder.imageView.setBackgroundResource(R.drawable.option_a);
    break;
   case 1:
    viewHolder.imageView.setBackgroundResource(R.drawable.option_b);
    break;
   case 2:
    viewHolder.imageView.setBackgroundResource(R.drawable.option_c);
    break;
   case 3:
    viewHolder.imageView.setBackgroundResource(R.drawable.option_d);
    break;
  }
  viewHolder.relativeLayout.setBackgroundResource(R.drawable.shape_rect_gray);
 }
 return convertView;
}

class ViewHolder{
 private TextView textView;
 private ImageView imageView;
 private RelativeLayout relativeLayout;
}
}

最后在activity中设置适配器：

GridViewRadioAdapter adapter = new GridViewRadioAdapter(mContext);
adapter.setStr(options); //传入问题的选项
mGridView.setAdapter(adapter);
mGridView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> arg0, View arg1, int position, long arg3) {
 adapter.setSelection(position); //传值更新
 adapter.notifyDataSetChanged(); //每一次点击通知adapter重新渲染
}
});

来源：http://www.cnblogs.com/wangxinqiang1995/p/6808483.html