Android开发之组件GridView简单使用方法示例

<?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>