滚动图片

来源：互联网发布：iphone7 二次曝光软件编辑：程序博客网时间：2024/06/05 21:11

滚动图片播放器

1建立布局

?xml version="1.0" encoding="utf-8"?><RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"    android:id="@+id/activity_main"    android:layout_width="match_parent"    android:layout_height="match_parent">    <RelativeLayout        android:layout_width="match_parent"        android:layout_height="160dp">        <android.support.v4.view.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:padding="5dp"            android:orientation="vertical"            android:layout_alignParentBottom="true"            android:layout_alignParentRight="true"            android:gravity="center_horizontal"            android:background="#66000000">            <TextView                android:id="@+id/tv_desc"                android:textColor="@android:color/white"                android:singleLine="true"                android:layout_width="wrap_content"                android:layout_height="wrap_content" />            <LinearLayout                android:id="@+id/ll_point_container"                android:layout_width="wrap_content"                android:layout_marginTop="5dp"                android:orientation="horizontal"                android:layout_height="wrap_content">            </LinearLayout>        </LinearLayout>    </RelativeLayout></RelativeLayout>

2 初始化布局

public class MainActivity extends Activity implements OnPageChangeListener{        private ViewPager viewPager;    private LinearLayout ll_point_container;    private TextView tv_desc;    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_main);        // 初始化布局 View视图        initViews();    }    private void initViews() {        viewPager = (ViewPager) findViewById(R.id.viewpager);        viewPager.setOnPageChangeListener(this);// 设置页面更新监听//      viewPager.setOffscreenPageLimit(1);// 左右各保留几个对象        ll_point_container = (LinearLayout) findViewById(R.id.ll_point_container);        tv_desc = (TextView) findViewById(R.id.tv_desc);    }}

3.1加小白点, 指示器
3.1.1在animator文件夹下创建selector_bg_point.xml

<?xml version="1.0" encoding="utf-8"?><selector xmlns:android="http://schemas.android.com/apk/res/android">    <item android:state_enabled="true" android:drawable="@drawable/shape_bg_point_enable"/>    <item android:state_enabled="false" android:drawable="@drawable/shape_bg_point_disable"/></selector>

3.1.2在drawable下创建shape_bg_point_disable.xml

<?xml version="1.0" encoding="utf-8"?><shape xmlns:android="http://schemas.android.com/apk/res/android"    android:shape="oval">    <corners android:radius="5dp"/>    <solid android:color="#FFFFFF"/></shape>

3.1.3在drawable下创建shape_bg_point_enable.xml

<?xml version="1.0" encoding="utf-8"?><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>

3.2初始化数据

...import android.widget.LinearLayout.LayoutParams;public class MainActivity extends Activity implements OnPageChangeListener{        ...    private int[] imageResIds;    private ArrayList<ImageView> imageViewList;    private String[] contentDescs;    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_main);        ...        // Model数据        initData();       }    private void initData() {        // 初始化要显示的数据        // 图片资源id数组        imageResIds = new int[]{R.drawable.a, R.drawable.b, R.drawable.c, R.drawable.d, R.drawable.e};        // 文本描述        contentDescs = new String[]{                "image1",                "image2",                "image3",                "image4",                "image5"        };        // 初始化要展示的5个ImageView        imageViewList = new ArrayList<ImageView>();        ImageView imageView;        View pointView;        LayoutParams layoutParams;        for (int i = 0; i < imageResIds.length; i++) {            // 初始化要显示的图片对象            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.selector_bg_point);            layoutParams = new LinearLayout.LayoutParams(5, 5);            if(i != 0)                layoutParams.leftMargin = 10;            // 设置默认所有都不可用            pointView.setEnabled(false);            ll_point_container.addView(pointView, layoutParams);        }    }    ...}

4初始化适配器

public class MainActivity extends Activity implements OnPageChangeListener{    ...    private int previousSelectedPosition = 0;    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_main);        ...        // Controller 控制器    }    private void initAdapter() {        ll_point_container.getChildAt(0).setEnabled(true);        tv_desc.setText(contentDescs[0]);        previousSelectedPosition = 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 - (Integer.MAX_VALUE / 2 % imageViewList.size());        viewPager.setCurrentItem(5000000); // 设置到某个位置    }    class MyAdapter extends PagerAdapter{        @Override        public int getCount() {            return Integer.MAX_VALUE;        }        // 3. 指定复用的判断逻辑, 固定写法        @Override        public boolean isViewFromObject(View view, Object object) {//                      // 当划到新的条目, 又返回来, view是否可以被复用.            // 返回判断规则            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) {            int newPosition = position % imageViewList.size();            ImageView imageView = imageViewList.get(newPosition);            // 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; // 必须重写, 否则报异常        }        // 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);        }    }}

5侧滑事件处理

public class MainActivity extends Activity implements OnPageChangeListener{    ...    @Override    public void onPageScrolled(int position, float positionOffset,int positionOffsetPixels) {        // 滚动时调用    }    @Override    public void onPageSelected(int position) {        // 新的条目被选中时调用        int newPosition = position % imageViewList.size();        //设置文本         tv_desc.setText(contentDescs[newPosition]);         ll_point_container.getChildAt(previousSelectedPosition).setEnabled(false);         ll_point_container.getChildAt(newPosition).setEnabled(true);        // 记录之前的位置        previousSelectedPosition  = newPosition;    }    @Override    public void onPageScrollStateChanged(int state) {        // 滚动状态变化时调用    }}

6添加自动播放功能

public class MainActivity extends Activity implements OnPageChangeListener{    ...    boolean isRunning = false;    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_main);        ...        // 开启轮询        new Thread(){            public void run() {                isRunning = true;                while(isRunning){                    try {                        Thread.sleep(2000);                    } catch (InterruptedException e) {                        e.printStackTrace();                    }                    // 往下跳一位                    runOnUiThread(new Runnable() {                        @Override                        public void run() {                            System.out.println("设置当前位置: " + viewPager.getCurrentItem());                            viewPager.setCurrentItem(viewPager.getCurrentItem()+1);                                                 }                    });                }            };        }.start();    }    //销毁处理    @Override    protected void onDestroy() {        super.onDestroy();        isRunning = false;    }

7点击事件处理

 public Object instantiateItem(ViewGroup container, int position) {            ...            ImageView imageView = imageViewList.get(newPosition);            //点击响应            imageView.setOnClickListener(new View.OnClickListener() {                @Override                public void onClick(View view) {                    Toast.makeText(getApplicationContext()," position" + position,Toast.LENGTH_SHORT).show();                }            });            // 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; // 必须重写, 否则报异常        }

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