<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".MainActivity">
<androidx.constraintlayout.widget.ConstraintLayout
android:layout_width="match_parent"
android:layout_height="160dp" >
<androidx.viewpager.widget.ViewPager
android:id="@+id/viewpager"
android:layout_width="match_parent"
android:layout_height="match_parent" />
<LinearLayout
android:layout_width="match_parent"
android:layout_height="40dp"
android:layout_alignParentBottom="true"
android:background="#66000000"
android:gravity="center_horizontal"
android:orientation="vertical"
android:padding="5dp"
app:layout_constraintBottom_toBottomOf="@+id/viewpager">
<TextView
android:id="@+id/tv_desc"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:singleLine="true"
android:text="社会"
android:textColor="@android:color/white" />
<LinearLayout
android:id="@+id/ll_point_container"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginTop="5dp"
android:orientation="horizontal"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent" />
</LinearLayout>
</androidx.constraintlayout.widget.ConstraintLayout>
</androidx.constraintlayout.widget.ConstraintLayout>
public class MainActivity extends AppCompatActivity implements ViewPager.OnPageChangeListener {
private ViewPager viewPager;
private int[] imageResIds;
private ArrayList<ImageView> imageViewList;
private ArrayList<View> pointViews;
private LinearLayout ll_point_container;
private String[] contentDesc;
private TextView tv_desc;
private int lastEnablePoint = 0;
private boolean isRunning = true;
private Handler handler;
private Runnable runnable;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
// 初始化布局 View 视图
initViews();
// Model 数据
initData();
// Controller 控制器
initAdapter();
//1.
handler = new Handler();
runnable= new Runnable() {
@Override
public void run() {
viewPager.setCurrentItem(viewPager.getCurrentItem() + 1);
handler.postDelayed(this, 2000);
}
};
//2
// mTimer.schedule(mTimerTask, 2000, 2000);
//3
// handler.postDelayed( runnable, 2000 );
//开启轮询
// new Thread() {
// public void run() {
// while(isRunning) {
// try {
// Thread.sleep(2000);
// } catch (InterruptedException e) {
// e.printStackTrace();
// }
// //往下跳一位
// runOnUiThread(new Runnable() {
// @Override
// public void run() {
// viewPager.setCurrentItem(viewPager.getCurrentItem() + 1);
// }
// });
// }
//
// }
// }.start();
}
@Override
protected void onPause() {
super.onPause();
handler.removeCallbacksAndMessages( null );
}
@Override
protected void onResume() {
super.onResume();
handler.postDelayed( runnable, 2000 );
}
@Override
protected void onDestroy() {
super.onDestroy();
isRunning = false;
}
private void initViews() {
viewPager = (ViewPager) findViewById(R.id.viewpager);
viewPager.setOnPageChangeListener(this);// 设置滚动更新
viewPager.setOnTouchListener(new View.OnTouchListener() {
@Override
public boolean onTouch(View v, MotionEvent event) {
switch (event.getAction()) {
case MotionEvent.ACTION_DOWN:
case MotionEvent.ACTION_MOVE:
handler.removeCallbacksAndMessages( null );
break;
case MotionEvent.ACTION_UP:
handler.postDelayed( runnable, 2000 );
break;
}
return false;
}
});
tv_desc = (TextView) findViewById(R.id.tv_desc);
ll_point_container = findViewById(R.id.ll_point_container);
}
private void initAdapter() {
ll_point_container.getChildAt(0).setEnabled(true);
tv_desc.setText(contentDesc[0]);
// 设置适配器
viewPager.setAdapter(new MyAdapter());
//默认设置到中间的某个位置
int pos = Integer.MAX_VALUE / 2;
//viewPager.setCurrentItem(pos - 3);
viewPager.setCurrentItem(0);
}
private void initData() {
// 初始化要显示的数据
// 图片资源id数组
imageResIds = new int[] { R.drawable.lunbo1, R.drawable.lunbo2, R.drawable.lunbo3,
R.drawable.lunbo4};
// 文本描述
contentDesc = new String[] { "巩俐不低俗，我就不能低俗", "朴树又回来啦！再唱经典老歌引万人大合唱",
"揭秘北京电影如何升级", "乐视网TV版大派送", "热血屌丝的反杀" };
imageViewList = new ArrayList<ImageView>();
pointViews = new ArrayList<View>();
ImageView imageView;
View pointView;
LinearLayout.LayoutParams layoutParams;
for (int i = 0; i < imageResIds.length; i++) {
imageView = new ImageView(this);
imageView.setBackgroundResource(imageResIds[i]);
imageViewList.add(imageView);
// 加小白点，指示器
pointView = new View(this);
pointView.setBackgroundResource(R.drawable.select);
layoutParams = new LinearLayout.LayoutParams(7, 7);
if (i != 0) {
layoutParams.leftMargin = 10;
}
pointView.setEnabled(false);
ll_point_container.addView(pointView, layoutParams);
}
}
class MyAdapter extends PagerAdapter {
@Override
public int getCount() {
return Integer.MAX_VALUE;
}
// 3、指定复用的判断逻辑
@Override
public boolean isViewFromObject(View view, Object object) {
// 当滑到新的条目，又返回来，view是否可以被复用
return view == object;
}
// 1、返回要显示的条目内容，创建条目
@Override
public Object instantiateItem(ViewGroup container, int position) {
// container：容器：ViewPager
// position：当前要显示的条目的位置
position = position % 4;
ImageView imageView = imageViewList.get(position);
// a、把view对象添加到container中
container.addView(imageView);
// b、把view对象返回给框架，适配器
return imageView; // 必须要重写，否则抛异常
}
// 2、销毁条目
@Override
public void destroyItem(ViewGroup container, int position, Object object) {
// object 要销毁的对象
container.removeView((View) object);
}
}
@Override
public void onPageScrolled(int position, float positionOffset,
int positionOffsetPixels) {
// 滚动时调用
}
@Override
public void onPageSelected(int position) {
// 新条目被选中时调用
position = position % 4;
tv_desc.setText(contentDesc[position]);
// 把之前的禁用，把最新的启用
ll_point_container.getChildAt(lastEnablePoint).setEnabled(false);
ll_point_container.getChildAt(position).setEnabled(true);
lastEnablePoint = position;
}
@Override
public void onPageScrollStateChanged(int state) {
// 滚动状态变化时调用
}
}
<shape xmlns:android="http://schemas.android.com/apk/res/android" android:shape="oval" >
<corners android:radius="5dp" />
<solid android:color="@android:color/white" />
</shape>
<shape xmlns:android="http://schemas.android.com/apk/res/android" android:shape="oval" >
<corners android:radius="5dp" />
<solid android:color="@android:color/darker_gray" />
</shape>
<selector xmlns:android="http://schemas.android.com/apk/res/android">
<item android:state_enabled="true" android:drawable="@drawable/shap1"></item>
<item android:state_enabled="false" android:drawable="@drawable/shap2"></item>
</selector>
