public class MainActivity extends Activity {ArrayList<String> fileNames = new ArrayList<String>(); //本地图片路径
@Overrideprotected void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.activity_main);initData();GridView listView = (GridView) findViewById(R.id.gridview);//ImageAdapter imageAdapter = new ImageAdapter(getApplicationContext(),Images.imageUrls);ImageAdapter imageAdapter = new ImageAdapter(getApplicationContext(), fileNames);listView.setAdapter(imageAdapter);}private void initData() {fileNames.clear();Cursor cursor = getContentResolver().query(Media.EXTERNAL_CONTENT_URI, null, null, null, null);while (cursor.moveToNext()) {byte[] data = cursor.getBlob(cursor.getColumnIndex(Media.DATA)); //图片的保存位置的数据fileNames.add(new String(data, 0, data.length - 1));}}}

<RelativeLayout 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"tools:context="com.example.imagelist.MainActivity" ><GridViewandroid:id="@+id/gridview"android:layout_width="match_parent"android:layout_height="wrap_content"android:numColumns="3" android:horizontalSpacing="2dp"android:verticalSpacing="2dp"></GridView></RelativeLayout>

public class ImageAdapter extends BaseAdapter {private Context context;private String[] imageUrls;ArrayList<String> fileNames;private LinearLayout.LayoutParams mImageViewLayoutParams;/** public ImageAdapter(Context context, String[] imageUrls) { super();* this.context = context; this.imageUrls = imageUrls; }*/public ImageAdapter(Context context, ArrayList<String> fileNames) {super();this.context = context;this.fileNames = fileNames;DisplayMetrics dm = context.getResources().getDisplayMetrics();  int wh = dm.widthPixels;int w = (wh - context.getResources().getDimensionPixelSize(R.dimen.test) * 2) / 3;mImageViewLayoutParams = new LinearLayout.LayoutParams(w, w);}@Overridepublic int getCount() {return fileNames.size();}@Overridepublic Object getItem(int position) {return null;}@Overridepublic long getItemId(int position) {return position;}@Overridepublic View getView(int position, View convertView, ViewGroup parent) {View view;if (convertView == null) {view = LayoutInflater.from(context).inflate(R.layout.item, null);} else {view = convertView;}ImageView image = (ImageView) view.findViewById(R.id.image);image.setLayoutParams(mImageViewLayoutParams);Glide.with(context).load(fileNames.get(position)).centerCrop().placeholder(R.color.test).crossFade().into(image);return view;}
}

<?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/image"android:layout_width="wrap_content"android:layout_height="wrap_content"android:scaleType="centerCrop"/></LinearLayout>