Simple tutorial on Android-gun 10 (Gallery component Gallery practical research) and androidgallery

Simple tutorial on Android-gun 10 (Gallery component Gallery practical research) and androidgallery

The Gallery component is used to drag and drop images. Let's take a look at how it is implemented.

1. Implement Gallery

1. The layout file is simple:

<?xml version="1.0" encoding="utf-8"?><LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"    android:id="@+id/MyLayout"    android:layout_width="match_parent"    android:layout_height="match_parent"    android:background="#FFFFFF"    android:orientation="vertical" >    <Gallery        android:id="@+id/myGallery"        android:gravity="center_vertical"        android:layout_width="match_parent"        android:layout_height="wrap_content" /></LinearLayout>

2. Custom adapter class. You can directly override several methods in the BaseAdapter class.

Package org. yayun. demo; import android. content. context; import android. view. view; import android. view. viewGroup; import android. widget. baseAdapter; import android. widget. gallery; import android. widget. imageView; import android. widget. gallery. layoutParams; public class ImageGalleryAdapter extends BaseAdapter {private Context context; private int imgRes [] = new int [] {R. drawable. ispic_a, R. drawable. ispic_ B, R. drawable. ispic_c, R. drawable. ispic_d, R. drawable. ispic_e,}; public ImageGalleryAdapter (Context c) {// constructor, used to obtain the Context object this. context = c;} public int getCount () {return imgRes. length;} public Object getItem (int position) {return imgRes [position];} public long getItemId (int position) {return imgRes [position];} public View getView (int position, view convertView, ViewGroup parent) {ImageView img = new ImageView (this. context); img. setBackgroundColor (0 xFFFFFFFF); img. setImageResource (this. imgRes [position]); // sets the resource img. setScaleType (ImageView. scaleType. CENTER); // CENTER the img. setLayoutParams (new Gallery. layoutParams (LayoutParams. WRAP_CONTENT, LayoutParams. WRAP_CONTENT); return img ;}}

3. MainActivity. java:

Package org. yayun. demo; import android. app. activity; import android. OS. bundle; import android. view. view; import android. widget. adapterView; import android. widget. toast; import android. widget. adapterView. onItemClickListener; import android. widget. gallery; public class MainActivity extends Activity {private Gallery gallery; public void onCreate (Bundle savedInstanceState) {super. onCreate (savedInstanceState );/ /Life cycle method super. setContentView (R. layout. main); // set the layout manager gallery = (Gallery) findViewById (R. id. myGallery); gallery. setAdapter (new ImageGalleryAdapter (this); gallery. setOnItemClickListener (new OnItemClickListener () {public void onItemClick (AdapterView <?> Parent, View view, int position, long id) {Toast. makeText (MainActivity. this, "the number you selected" + String. valueOf (position + 1) + "Images", Toast. LENGTH_SHORT ). show ();}});}}

4. Run the following instance:

2. Integration of Gallery and ImageSwitcher

In this case, we use the SimpleAdapter class to complete the Gallery.

1. layout file:

<?xml version="1.0" encoding="utf-8"?><LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"    android:id="@+id/MyLayout"    android:layout_width="match_parent"    android:layout_height="match_parent"    android:background="#FFFFFF"    android:gravity="bottom"    android:orientation="vertical" >    <ImageSwitcher        android:id="@+id/imageSwitcher"        android:layout_width="fill_parent"        android:layout_height="wrap_content" >    </ImageSwitcher>    <Gallery        android:id="@+id/gallery"        android:layout_width="match_parent"        android:layout_height="wrap_content"        android:gravity="center_vertical"        android:spacing="5dp" /></LinearLayout>

2. Define a display template:

<?xml version="1.0" encoding="utf-8"?><LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"    android:layout_width="wrap_content"    android:layout_height="wrap_content"    android:background="#FFFFFF"    android:orientation="horizontal" >    <ImageView        android:id="@+id/img"        android:layout_width="wrap_content"        android:layout_height="wrap_content"        android:scaleType="center" /></LinearLayout>

3. MainActivity. java program:

Package org. yayun. demo; import java. lang. reflect. field; import java. util. arrayList; import java. util. hashMap; import java. util. list; import java. util. map; import android. app. activity; import android. OS. bundle; import android. view. view; import android. widget. adapterView; import android. widget. imageSwitcher; import android. widget. imageView; import android. widget. simpleAdapter; import android. widget. toast; import Ndroid. widget. adapterView. onItemClickListener; import android. widget. gallery. layoutParams; import android. widget. gallery; import android. widget. viewSwitcher. viewFactory; public class MainActivity extends Activity {private Gallery gallery; private List <Map <String, Integer> list = new ArrayList <Map <String, Integer> (); private SimpleAdapter simpleAdapter; private ImageSwitcher imageSwitcher; public void on Create (Bundle savedInstanceState) {super. onCreate (savedInstanceState); // life cycle method super. setContentView (R. layout. main); // set the layout manager initAdapter (); gallery = (Gallery) findViewById (R. id. gallery); imageSwitcher = (ImageSwitcher) findViewById (R. id. imageSwitcher); imageSwitcher. setFactory (new ViewFactory () {public View makeView () {ImageView imageView = new ImageView (MainActivity. this); imageView. setBackgro UndColor (0 xFFFFFFFF); imageView. setScaleType (ImageView. scaleType. CENTER); imageView. setLayoutParams (new ImageSwitcher. layoutParams (LayoutParams. WRAP_CONTENT, LayoutParams. WRAP_CONTENT); return imageView ;}}); gallery. setAdapter (simpleAdapter); gallery. setOnItemClickListener (new OnItemClickListener () {public void onItemClick (AdapterView <?> Parent, View view, int position, long id) {Map <String, Integer> map = (Map <String, Integer>) MainActivity. this. simpleAdapter. getItem (position); // retrieves mapMainActivity. this. imageSwitcher. setImageResource (map. get ("img"); // set the display image});} private void initAdapter () {Field [] fields = R. drawable. class. getDeclaredFields (); // the Java reflection mechanism obtains all resource images for (int I = 0; I <fields. length; I ++) {if (fields [I]. getName (). startsWith ("ispic _") {// start Map <String, Integer> map = new HashMap <String, Integer> (); try {map. put ("img", fields [I]. getInt (R. drawable. class);} catch (IllegalArgumentException e) {// TODO Auto-generated catch blocke. printStackTrace ();} catch (IllegalAccessException e) {// TODO Auto-generated catch blocke. printStackTrace ();} this. list. add (map) ;}} simpleAdapter = new SimpleAdapter (this, this. list, R. layout. grid_layout, new String [] {"img"}, new int [] {R. id. img });}}

4. Run the instance: