<&#63;XMl version="1.0" encoding="utf-8"?> <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"  tools:context=".MainActivITy" >  <!--定义一个GridView组件-->  <GridView   android:id="@+id/grid01"   android:layout_width="match_parent"   android:layout_height="wrap_content"   android:horizontalSpacing="1pt"   android:verticalSpacing="1pt"   android:numColumns="3"   android:gravity="center"/>  <!--定义一个ImageView组件-->  <ImageView   android:id="@+id/image_view"   android:layout_width="240dp"   android:layout_height="240dp"   android:layout_gravity="center_horizontal"/> </LinearLayout>  

 public class MainActivity extends Activity {  PRivate GridView gridView;  //定义字符串数组作为提示的文本  private ImageView imageView;  private int[] photoId = new int[]{    R.drawable.huangjindiao, R.drawable.piaopiao,    R.drawable.xiaochouyu, R.drawable.paodangyu,    R.drawable.addphoto, R.drawable.huangjinxiahu  };  @override  protected void onCreate(Bundle savedInstancestate) {   suPEr.onCreate(savedInstanceState);   setContentView(R.layout.activity_main);   //创建一个list对象，list对象的元素是Map   List<;map<String,Object>> listItems = new ArrayList<Map<String,Object>>();   for (int i = 0 ; i < photoId.length ; i ++ ){    Map<String,Object> photolist = new HashMap<String, Object>();    photolist.put("image",photoId[i]);    listItems.add(photolist);   }   //获取图片的imageView   imageView = (ImageView) findViewById(R.id.image_view);   //创建一个SimpleAdapter   SimpleAdapter simpleAdapter = new SimpleAdapter(this,listItems,   //arry_list只有一个ImageView放图片 代码下面给出     R.layout.array_list,     new String[]{"image"}, new int[]{R.id.image});   gridView = (GridView) findViewById(R.id.grid01);   //为gridview设置adapter   gridView.setAdapter(simpleAdapter);   //添加列表项中被选中的监听器   gridView.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {    @Override    public void onItemSelected(AdapterView<?> parent, View view, int position, long id) {     //显示当前被选中的图片     imageView.setImageResource(photoId[position]);    }    @Override    public void onNothingSelected(AdapterView<?> parent) {    }   });   //添加列表中被单击的监听器   gridView.setOnItemClickListener(new AdapterView.OnItemClickListener() {    @Override    public void onItemClick(AdapterView<?> parent, View view, int position, long id) {     //显示被单击的图片     imageView.setImageResource(photoId[position]);    }   });   //点击图片保存   imageView.setOnClickListener(new View.OnClickListener() {    @Override    public void onClick(View v) {     String[] PERMISSIONS = {       "android.permission.READ_EXTERNAL_STORAGE",       "android.permission.WRITE_EXTERNAL_STORAGE" };     //检测是否有写的权限     int permission = ContextCompat.checkSelfPermission(MainActivity.this,       "android.permission.WRITE_EXTERNAL_STORAGE");     if (permission != PackageManager.PERMISSION_GRANTED) {      // 没有写的权限，去申请写的权限，会弹出对话框      ActivityCompat.requestPermissions(MainActivity.this, PERMISSIONS,1);     }     try {      //创建savephoto类保存图片      SavePhoto savePhoto = new SavePhoto(MainActivity.this);      savePhoto.SaveBitmapFromView(imageView);     } catch (ParseException e) {      e.printStackTrace();     }    }   });  } }  

 <?xml version="1.0" encoding="utf-8"?> <ImageView xmlns:android="http://schemas.android.com/apk/res/android"  android:id="@+id/image"  android:layout_width="100dp"  android:layout_height="100dp"  android:scaleType="fitXY"> </ImageView>