SimpleAdapter、GridView简易使用实现九宫格实例

由于写项目时是在Fragment中code的，故在采用的是fragment：

第一种使用SimpleAdapter

    新建一个主activity_dzzy.xml如下：

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"    xmlns:tools="http://schemas.android.com/tools"    android:layout_width="match_parent"    android:layout_height="match_parent"    android:orientation="vertical"    android:paddingBottom="@dimen/activity_vertical_margin"    tools:context=".MainActivity" >       <GridView            android:id="@+id/gridView"           android:layout_width="fill_parent"           android:layout_height="wrap_content"           android:numColumns="auto_fit"<!--定义每行显示的列数，auto_fit自定义-->           /></LinearLayout>

   建立activity_dzzy_item2.xml

<?xml version="1.0" encoding="utf-8"?><LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"    android:layout_width="match_parent"    android:layout_height="match_parent"    android:orientation="vertical" >    <ImageView        android:id="@+id/img"        android:layout_width="wrap_content"        android:layout_height="100dp"        android:paddingTop="10dp"        android:paddingLeft="10dp"        android:paddingRight="10dp"         android:layout_gravity="center"        android:scaleType="fitXY" /></LinearLayout>

    在对应的fragment中

  

public class DzzyFragment extends Fragment {private GridView gridView;private int[] imgs = { };//图片资源public View onCreateView(LayoutInflater inflater, ViewGroup container,Bundle savedInstanceState) {View view = inflater.inflate(R.layout.activity_dzzy, container, false);setHasOptionsMenu(true);gridView = (GridView) view.findViewById(R.id.gridView);ArrayList<HashMap<String, Object>> imagelist = new ArrayList<HashMap<String, Object>>();for (int i = 0; i < imgs.length; i++) {HashMap<String, Object> map = new HashMap<String, Object>();map.put("img", imgs[i]);imagelist.add(map);}SimpleAdapter sa = new SimpleAdapter(getActivity().getApplicationContext(), imagelist,R.layout.activity_dzzy_item2, new String[] { "img" },new int[] { R.id.img });gridView.setAdapter(sa);return view;}}

但是由于该方法对drawable没有采用任何的处理，如果图片数量多或者比较大时占用内存比较严重，严重时可能oom。

第二种方法采用自定义的adapter,并对引用的bitmap进行加工，并及时回收

引用上面的两个xml

修改Fragment

private GridView gridView ;<pre name="code" class="java"><span style="white-space:pre"></span>private int[] imgs = { };//图片资源

public List<Bitmap> bitmaps=new ArrayList<Bitmap>();public View onCreateView(LayoutInflater inflater, ViewGroup container,Bundle savedInstanceState) {View view = inflater.inflate(R.layout.activity_dzzy, container, false);setHasOptionsMenu(true);gridView = (GridView) view.findViewById(R.id.gridView);for(int i:imgs){bitmaps.add(GetBitmap.getBitmap(getActivity().getApplicationContext(), i));}MySimpleAdapter msa=new MySimpleAdapter(bitmaps);gridView.setAdapter(msa);return view;}@Overridepublic void onDestroy() {/* * 回收本地图片资源 * */for(Bitmap bitmap:bitmaps){if(bitmap != null && !bitmap.isRecycled()){bitmap.recycle();bitmap=null;}} System.gc();super.onDestroy();}//适配器public class MySimpleAdapter extends BaseAdapter{private LayoutInflater mInflater;private List<Bitmap> bitmaps;public MySimpleAdapter(List<Bitmap> bitmaps) {this.mInflater = LayoutInflater.from(getActivity().getApplicationContext());this.bitmaps=bitmaps;}@Overridepublic int getCount() {return bitmaps.size();}@Overridepublic Object getItem(int arg0) {return bitmaps.get(arg0);}@Overridepublic long getItemId(int arg0) {return arg0;}@Overridepublic View getView(int position, View convertView, ViewGroup parent) {ViewHolder holder = null;if (convertView == null) {holder = new ViewHolder();convertView = mInflater.inflate(R.layout.activity_dzzy_item2, null); holder.image = (ImageView) convertView.findViewById(R.id.img); convertView.setTag(holder);} else {holder = (ViewHolder) convertView.getTag();}holder.image.setImageBitmap(bitmaps.get(position));return convertView;}}class ViewHolder {public ImageView image;}

新建类GetBitmap：通过图片id获取图片的bitmap

 

public class GetBitmap {public static Bitmap getBitmap(Context context,int resId){BitmapFactory.Options opt = new BitmapFactory.Options();opt.inPreferredConfig = Bitmap.Config.RGB_565;opt.inPurgeable = true;opt.inInputShareable = true;// 获取资源图片InputStream is = context.getResources().openRawResource(resId);return BitmapFactory.decodeStream(is, null, opt);}}

这样能有效的减少图片内存的占用，能灵活的对图片进行调整、回收，建议采用第二种方法。