添加弹幕

效果图：

　　　　　　　　　　　　　　　　　　　　

1、  添加依赖

implementation 'com.github.ctiao:DanmakuFlameMaster:0.5.3'//  bilibili 开源弹幕库

2、编写布局   DanmakuView  覆盖在 VideoView

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
    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:id="@+id/activity_main"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".MainActivity"
    android:orientation="vertical">
    <RelativeLayout
        android:layout_width="400dp"
        android:layout_height="400dp">
        <VideoView
            android:id="@+id/video"
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:layout_centerInParent="true"
            android:background="@android:color/white"
            />
        <master.flame.danmaku.ui.widget.DanmakuView
            android:id="@+id/DanmakuView"
            android:layout_width="match_parent"
            android:layout_height="match_parent" />
        <LinearLayout
        android:layout_alignParentBottom="true"
        android:id="@+id/operation_layout"
        android:layout_width="match_parent"
        android:orientation="horizontal"
        android:layout_height="50dp">
        <EditText
            android:id="@+id/et"
            android:layout_width="0dp"
            android:layout_height="match_parent"
            android:layout_weight="1"/>
        <ImageView
            android:id="@+id/send"
            android:layout_width="wrap_content"
            android:layout_height="match_parent"
            app:srcCompat="@android:drawable/ic_menu_send" />
    </LinearLayout>
    </RelativeLayout>
</LinearLayout>

3、 编写相关逻辑

public class MainActivity extends AppCompatActivity {
    private static final String TAG = "MainActivity";
    private  boolean showDanmaku;
    private DanmakuView danmakuView;
    private DanmakuContext danmakuContext;

    private BaseDanmakuParser parser = new BaseDanmakuParser() {
        @Override
        protected IDanmakus parse() {
            return new Danmakus();
        }
    };

    /**
     *   添加弹幕
     * @param content
     * @param withBorder
     */
    private  void  addDanmaku(String content,boolean withBorder){
        BaseDanmaku danmaku = danmakuContext.mDanmakuFactory.createDanmaku(BaseDanmaku.TYPE_SCROLL_LR);
        danmaku.text = content;
        danmaku.padding = 5;
        danmaku.textSize = 50;//DensityUtil.px2dip(MainActivity.this,100);
        danmaku.textColor = Color.BLACK;
        danmaku.setTime(danmakuView.getCurrentTime());
        if (withBorder){
            danmaku.borderColor = Color.GREEN;
        }
        danmakuView.addDanmaku(danmaku);
    }
    /**
     *   随机生成弹幕
     */
    private void generateSomeDanmaku() {
        new Thread(new Runnable() {
            @Override
            public void run() {
                while(showDanmaku){
                    int time = new Random().nextInt(300);
                    String content = ""+time+time;
                    addDanmaku(content,false);

                    try {
                        Thread.sleep(time);
                    } catch (InterruptedException e) {
                        e.printStackTrace();
                    }
                }
            }
        }).start();
    }
    /**
       *暂停时 弹幕跟着暂停
     */
    @Override
    protected void onResume() {
        super.onResume();
        if (danmakuView!=null&&danmakuView.isPrepared()){
            danmakuView.resume();
        }
    }
    /**
     *   退出时销毁弹幕
     */
    @Override
    protected void onDestroy() {
        super.onDestroy();
        showDanmaku = false;
        if (danmakuView!=null){
            danmakuView.release();// 释放
            danmakuView = null;
        }
    }
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        VideoView videoView = findViewById(R.id.video);
        videoView.setVideoURI(Uri.parse("http://ips.ifeng.com/video.ifeng.com/video04/2011/03/24/480x360_offline20110324.mp4"));
        videoView.start();
        danmakuView=findViewById(R.id.DanmakuView);
        danmakuView.enableDanmakuDrawingCache(true);
        danmakuView.setCallback(new DrawHandler.Callback() {
            @Override
            public void prepared() {
                showDanmaku = true;
                danmakuView.start();
                generateSomeDanmaku();
            }
            @Override
            public void updateTimer(DanmakuTimer timer) { }
            @Override
            public void danmakuShown(BaseDanmaku danmaku) { }
            @Override
            public void drawingFinished() { }
        });
        danmakuContext = DanmakuContext.create();
        danmakuView.prepare(parser,danmakuContext);
        final LinearLayout operationLayout = findViewById(R.id.operation_layout);
        ImageView send = findViewById(R.id.send);
        final EditText editText = findViewById(R.id.et);
        danmakuView.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                if (operationLayout.getVisibility()==View.GONE){
                    operationLayout.setVisibility(View.VISIBLE);
                }else {
                    operationLayout.setVisibility(View.GONE);
                }
            }
        });
        send.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                String content = editText.getText().toString();
                if (!TextUtils.isEmpty(content)){
                    addDanmaku(content,true);
                    editText.setText("");
                }
            }
        });
    }
}