今天主要探究Gallery和Animation的使用。 制作一个美女图片集锦。
1. 首先需要做一个列表， 用来显示类别：
public class CategoryActivity extends Activity implements OnItemClickListener{ private ListView mList; LayoutInflater mInflater; private Integer[] title = { R.string.jingxuan, R.string.mingxing, R.string.xinggan, R.string.cosplay, R.string.socks, R.string.more }; @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.category_list); mList = (ListView) findViewById(R.id.category_list); long time = System.currentTimeMillis(); if (time%3==0) { mList.setBackgroundResource(R.drawable.longze2); } else if (time%3==1){ mList.setBackgroundResource(R.drawable.pic02); } else { mList.setBackgroundResource(R.drawable.pic05); } mInflater = LayoutInflater.from(this); mList.setAdapter(new TitleAdapter(this)); mList.setOnItemClickListener(this); }...
需要自定义个一个TitleAdapter集成BaseAdapter,
private class TitleAdapter extends BaseAdapter { private Context mContext; public TitleAdapter(Context context) { mContext = context; } @Override public int getCount() { // TODO Auto-generated method stub return title.length; } @Override public Object getItem(int arg0) { // TODO Auto-generated method stub return title[arg0]; } @Override public long getItemId(int position) { // TODO Auto-generated method stub return position; } @Override public View getView(int position, View convertView, ViewGroup parent) { ViewHolder vh = null; if (convertView == null) { convertView = mInflater.inflate(R.layout.category_item, null); vh = new ViewHolder(); vh.titleView = (TextView) convertView.findViewById(R.id.cate_title); //hilight the last 'more' title if (position == title.length -1) { vh.titleView.setTextColor(CategoryActivity.this.getResources().getColor(R.color.red)); } convertView.setTag(vh); } else { vh = (ViewHolder) convertView.getTag(); } //set image resource vh.titleView.setText(title[position]); return convertView; } /** * holder for caching UI component * @author hp * */ class ViewHolder { public TextView titleView; } }使用ViewHolder的好处就是对控件进行缓存， 以便下次取方便，提高访问效率。
2. 接下来就是对类别中的美女图片的显示了，
定义xml布局文件如下：
<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" >
<ImageView android:id="@+id/large_image"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:layout_alignParentTop="true"
/>
<TextView android:id="@+id/tip"
android:layout_width="fill_parent"
android:layout_height="30dp"
android:text="@string/slide_tip"
android:gravity="center_vertical"
android:textColor="#dd0000"
android:layout_above="@+id/gallery"/>
<Gallery
android:id="@+id/gallery"
android:layout_width="fill_parent"
android:layout_height="60dp"
android:gravity="center"
android:padding="5dp"
android:layout_alignParentBottom="true"
android:paddingBottom="10dp" />
<LinearLayout
android:id="@+id/miniAdLinearLayout"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:gravity="center_horizontal"
/>
</RelativeLayout>
类代码如下：
public class ViewActivity extends Activity implements OnItemSelectedListener { private Gallery mGallery; private ImageAdapter mAdapter; LayoutInflater mInflater; private ImageView largeView; private Animation mAnimation; private int categoryId; private String imgDir = ""; private Bitmap[] imageUri; private int showCount = 0; @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); this.setTitle(getIntent().getIntExtra(Constants.KEY_TITLE, R.string.app_name)); mGallery = (Gallery) findViewById(R.id.gallery); mInflater = LayoutInflater.from(this); mAdapter = new ImageAdapter(this); largeView = (ImageView) findViewById(R.id.large_image); largeView.setScaleType(ImageView.ScaleType.FIT_XY); mAnimation = AnimationUtils.loadAnimation(this, R.anim.alpha_ani); largeView.startAnimation(mAnimation); } public void onResume() { super.onResume(); showCount++; if (getIntent().getBooleanExtra(Constants.KEY_AD, false)) { if (showCount == 1) { AppConnect.getInstance(this).showOffers(this); } } else { //build from asset initFromIntent(); mGallery.setAdapter(mAdapter); mGallery.setOnItemSelectedListener(this); } } private void initFromIntent() { //set title Intent intent = getIntent(); categoryId = getIntent().getIntExtra(Constants.KEY_CATEGORY, 0); String basePath = "images/"; switch (categoryId) { //suggest hot images case 0: imgDir = "jingxuantuijian"; break; //super starts case 1: imgDir = "mingxing"; break; //sexy girls case 2: imgDir = "xinggan"; break; //cosplay case 3: imgDir = "cosplay"; break; case 4: imgDir = "socks"; break; default: imgDir = "xinggan"; break; } try { basePath += imgDir; AssetManager am = this.getAssets(); String[] files = am.list(basePath); imageUri = new Bitmap[files.length]; basePath += "/"; for(int i = 0; i < files.length; i++) { imageUri[i] = BitmapFactory.decodeStream(am.open(basePath + files[i])); } } catch (IOException e) { // TODO Auto-generated catch block e.printStackTrace(); } } private class ImageAdapter extends BaseAdapter { private Context mContext; public ImageAdapter(Context context) { mContext = context; } @Override public int getCount() { // TODO Auto-generated method stub return imageUri.length; } @Override public Object getItem(int arg0) { // TODO Auto-generated method stub return imageUri[arg0]; } @Override public long getItemId(int position) { // TODO Auto-generated method stub return position; } @Override public View getView(int position, View convertView, ViewGroup parent) { ViewHolder vh = null; if (convertView == null) { convertView = mInflater.inflate(R.layout.item, null); vh = new ViewHolder(); vh.imgV = (ImageView) convertView.findViewById(R.id.imageV); vh.imgV.setScaleType(ImageView.ScaleType.FIT_XY); convertView.setTag(vh); } else { vh = (ViewHolder) convertView.getTag(); } //set image resource vh.imgV.setImageBitmap(imageUri[position]); return convertView; } /** * holder for caching UI component * @author hp * */ class ViewHolder { public ImageView imgV; } } @Override public void onItemSelected(AdapterView<?> arg0, View arg1, int position, long arg3) { //recyle old bitmap BitmapDrawable drawable = (BitmapDrawable) largeView.getDrawable(); if (drawable != null && !drawable.getBitmap().isRecycled()) { drawable.getBitmap().recycle(); } largeView.setImageBitmap(imageUri[position]); largeView.startAnimation(mAnimation); } @Override public void onNothingSelected(AdapterView<?> arg0) { }}中间大图片的显示加上动画，
动画文件如下
<?xml version="1.0" encoding="utf-8"?>
<set xmlns:android="http://schemas.android.com/apk/res/android">
<alpha android:fromAlpha="0.1"
android:toAlpha="1.0"
android:duration="1500"/>
</set>
放在res/anim下。
实际效果请运行附件。
至此可完成。