android TV开发：使用ViewPager实现图片自动轮播效果
1.实现效果：ViewPager的子view响应点击事件 + 焦点脱离父控件（遥控器按键从子view直接跳到旁边控件）
（由于gif最大只能是2M，就只能录屏时间这么短，建议csdn可以上传容量更大的图片）
2.实现思路：ViewPager+自定义PagerAdapter+定时器ScheduledExecutorService
主要关注点：
①ScheduledExecutorService（定时周期的执行任务）
public class MainActivity extends AppCompatActivity {
private ScheduledExecutorService scheduledExecutorService;
private Handler mHandler = new Handler() {
public void handleMessage(android.os.Message msg) {
mViewPaper.setCurrentItem(currentItem);
}
};
//...
@Override
protected void onStart() {
super.onStart();
// 产生一个ExecutorService对象，这个对象只有一个线程可用来执行任务，若任务多于一个，任务将按先后顺序执行。
scheduledExecutorService = Executors.newSingleThreadScheduledExecutor();
scheduledExecutorService.scheduleWithFixedDelay(new ViewPageTask(), 4,4, TimeUnit.SECONDS);
}
private class ViewPageTask implements Runnable {
@Override
public void run() {
currentItem = (currentItem + 1) % imageIds.length;
mHandler.sendEmptyMessage(0);
}
}
@Override
protected void onStop() {
super.onStop();
if (scheduledExecutorService != null) {
scheduledExecutorService.shutdown();
scheduledExecutorService = null;
}
}
//....
} //做了两件事，第一：将当前视图添加到container中，第二：返回当前View
@Override
public Object instantiateItem(ViewGroup container, final int position) {
container.addView(images.get(position));
ImageView imageView = images.get(position);
imageView.setBackgroundResource(R.drawable.button_style);
imageView.setOnKeyListener(new View.OnKeyListener() {
@Override
public boolean onKey(View v, int keyCode, KeyEvent event) {
if (keyCode == KeyEvent.KEYCODE_DPAD_RIGHT && event.getAction() == KeyEvent.ACTION_DOWN) {
rightImgView2.requestFocusFromTouch();
rightImgView2.requestFocus();
return true;
}
if (keyCode == KeyEvent.KEYCODE_DPAD_LEFT && event.getAction() == KeyEvent.ACTION_DOWN) {
rightImgView.requestFocusFromTouch();
rightImgView.requestFocus();
return true;
}
return false;
}
});
imageView.setFocusable(true);
imageView.setFocusableInTouchMode(true);
imageView.setClickable(true);
imageView.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
Toast.makeText(mContext, "点击了第" + "" + position + "张图片", Toast.LENGTH_LONG).show();
}
});
return imageView;
}3.具体实现代码如下
public class MainActivity extends AppCompatActivity {
private ViewPager mViewPaper;
private List images;
private List dots;
private Handler mHandler = new Handler() {
public void handleMessage(android.os.Message msg) {
mViewPaper.setCurrentItem(currentItem);
}
};
private int currentItem;
//记录上一次点的位置
private int oldPosition = 0;
private TextView title;
private ViewPagerAdapter adapter;
private ScheduledExecutorService scheduledExecutorService;
//存放图片的id
private int[] imageIds = new int[]{
R.drawable.a,
R.drawable.b,
R.drawable.c,
R.drawable.d,
R.drawable.e
};
//存放图片的标题
private String[] titles = new String[]{
"挑战者联盟，薛之谦又来辣",
"老九门，又是李易峰这个傻叉",
"红色通道，再看刘烨英俊潇洒",
"神犬小七，小七居然是只猪",
"灭罪师，鬼知道这是什么剧"
};
private ImageView rightImgView;
private ImageView rightImgView1;
private ImageView rightImgView2;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
//定义mViewPaper旁边的控件
rightImgView = new ImageView(this);
rightImgView = (ImageView) findViewById(R.id.rightImgView);
rightImgView.setImageResource(R.drawable.right);
rightImgView1 = new ImageView(this);
rightImgView1 = (ImageView) findViewById(R.id.rightImgView1);
rightImgView1.setImageResource(R.drawable.right);
rightImgView2 = new ImageView(this);
rightImgView2 = (ImageView) findViewById(R.id.rightImgView3);
rightImgView.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
Intent intent = new Intent(MainActivity.this,MyGallaryActivity.class);
startActivity(intent);
}
});
mViewPaper = (ViewPager) findViewById(R.id.vp);
//显示的图片
images = new ArrayList();
for (int i = 0; i < imageIds.length; i++) {
ImageView imageView = new ImageView(this);
imageView.setImageResource(imageIds[i]);
images.add(imageView);
}
//显示的小点
dots = new ArrayList();
dots.add(findViewById(R.id.dot_0));
dots.add(findViewById(R.id.dot_1));
dots.add(findViewById(R.id.dot_2));
dots.add(findViewById(R.id.dot_3));
dots.add(findViewById(R.id.dot_4));
title = (TextView) findViewById(R.id.title);
title.setText(titles[0]);
mViewPaper.setAdapter(adapter = new ViewPagerAdapter(this, images));
//禁止手指控制滑动
mViewPaper.setOnTouchListener(new View.OnTouchListener() {
@Override
public boolean onTouch(View v, MotionEvent event) {
return true;
}
});
mViewPaper.setOnPageChangeListener(new ViewPager.OnPageChangeListener() {
@Override
public void onPageSelected(int position) {
title.setText(titles[position]);
dots.get(position).setBackgroundResource(R.drawable.dot_focused);
dots.get(oldPosition).setBackgroundResource(R.drawable.dot_normal);
oldPosition = position;
currentItem = position;
}
@Override
public void onPageScrolled(int arg0, float arg1, int arg2) {
}
@Override
public void onPageScrollStateChanged(int arg0) {
}
});
}
@Override
protected void onStart() {
super.onStart();
// 产生一个ExecutorService对象，这个对象只有一个线程可用来执行任务，若任务多于一个，任务将按先后顺序执行。
scheduledExecutorService = Executors.newSingleThreadScheduledExecutor();
scheduledExecutorService.scheduleWithFixedDelay(new ViewPageTask(), 4,4, TimeUnit.SECONDS);
}
private class ViewPageTask implements Runnable {
@Override
public void run() {
currentItem = (currentItem + 1) % imageIds.length;
mHandler.sendEmptyMessage(0);
}
}
@Override
protected void onStop() {
super.onStop();
if (scheduledExecutorService != null) {
scheduledExecutorService.shutdown();
scheduledExecutorService = null;
}
}
public class ViewPagerAdapter extends PagerAdapter {
private List images;
private Context mContext;
public ViewPagerAdapter(Context context, List img) {
this.mContext = context;
this.images = img;
}
//返回要滑动的VIew的个数
@Override
public int getCount() {
return images.size();
}
@Override
public boolean isViewFromObject(View view, Object object) {
return view == object;
}
//从当前container中删除指定位置（position）的View;
@Override
public void destroyItem(ViewGroup container, int position, Object object) {
container.removeView(images.get(position));
}
//做了两件事，第一：将当前视图添加到container中，第二：返回当前View
@Override
public Object instantiateItem(ViewGroup container, final int position) {
container.addView(images.get(position));
ImageView imageView = images.get(position);
imageView.setBackgroundResource(R.drawable.button_style);
imageView.setOnKeyListener(new View.OnKeyListener() {
@Override
public boolean onKey(View v, int keyCode, KeyEvent event) {
if (keyCode == KeyEvent.KEYCODE_DPAD_RIGHT && event.getAction() == KeyEvent.ACTION_DOWN) {
rightImgView2.requestFocusFromTouch();
rightImgView2.requestFocus();
return true;
}
if (keyCode == KeyEvent.KEYCODE_DPAD_LEFT && event.getAction() == KeyEvent.ACTION_DOWN) {
rightImgView.requestFocusFromTouch();
rightImgView.requestFocus();
return true;
}
return false;
}
});
imageView.setFocusable(true);
imageView.setFocusableInTouchMode(true);
imageView.setClickable(true);
imageView.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
Toast.makeText(mContext, "点击了第" + "" + position + "张图片", Toast.LENGTH_LONG).show();
}
});
return imageView;
}
}
}
4.源码+apk下载
主要参考 http://blog.csdn.net/l1028386804/article/details/48049913