如何在 Android 活动中运行背景视频？

Question

我想在我的应用程序的主要活动中实现背景视频。最初，我尝试使用 VideoView 将此视频添加为普通视频，但没有设置使其覆盖整个屏幕，因此我尝试使用表面视图添加相同的视频，但出现了一些问题。应用一启动就停止。

以下是我的代码：-

activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@+id/home_container"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent">

    <SurfaceView
        android:id="@+id/surface"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:paddingTop="10dip" />
</FrameLayout>

MainActivity.java

public class MainActivity extends Activity implements SurfaceHolder.Callback {

    private MediaPlayer mp = null;

    SurfaceView mSurfaceView=null;



    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);




        mp = new MediaPlayer();
        mSurfaceView = (SurfaceView) findViewById(R.id.surface);
        mSurfaceView.getHolder().addCallback(this);


        mSurfaceView.getHolder().addCallback(this);





    @Override
    public void surfaceCreated(SurfaceHolder holder) {


        Uri video = Uri.parse("android.resource://" + getPackageName() + "/"
                + R.raw.introduction);

        try {
            mp.setDataSource(String.valueOf(video));
        } catch (IOException e) {
            e.printStackTrace();
        }
        try {
            mp.prepare();
        } catch (IOException e) {
            e.printStackTrace();
        }

        //Get the dimensions of the video
        int videoWidth = mp.getVideoWidth();
        int videoHeight = mp.getVideoHeight();

        //Get the width of the screen
        int screenWidth = getWindowManager().getDefaultDisplay().getWidth();

        //Get the SurfaceView layout parameters
        android.view.ViewGroup.LayoutParams lp = mSurfaceView.getLayoutParams();

        //Set the width of the SurfaceView to the width of the screen
        lp.width = screenWidth;

        //Set the height of the SurfaceView to match the aspect ratio of the video
        //be sure to cast these as floats otherwise the calculation will likely be 0
        lp.height = (int) (((float)videoHeight / (float)videoWidth) * (float)screenWidth);

        //Commit the layout parameters
        mSurfaceView.setLayoutParams(lp);

        //Start video
        mp.setDisplay(holder);
        mp.start();

        mp.setDisplay(holder);



    }

    @Override
    public void surfaceChanged(SurfaceHolder surfaceHolder, int i, int i1, int i2) {

    }

    @Override
    public void surfaceDestroyed(SurfaceHolder surfaceHolder) {

    }
}

以下是相同的日志：-

2019-06-12 18:38:16.128 4261-4261/?我/艺术：不迟到 -Xcheck:jni (已经开启) 2019-06-12 18:38:16.129 4261-4261/? W/art：使用默认值的 X86 的意外 CPU 变体：x86 2019-06-12 18:38:16.504 4261-4261/com.example.liveinbliss W/系统：类加载器 引用的未知路径：/data/app/com.example.liveinbliss-1/lib/x86 2019-06-12 18:38:16.517 4261-4261/com.example.liveinbliss I/InstantRun：启动即时运行服务器：是主进程 2019-06-12 18:38:16.647 4261-4261/com.example.liveinbliss D/AndroidRuntime: 关闭虚拟机

--------- beginning of crash 2019-06-12 18:38:16.647 4261-4261/com.example.liveinbliss E/AndroidRuntime: FATAL EXCEPTION:

主要 进程：com.example.liveinbliss，PID：4261 java.lang.RuntimeException：无法启动活动 ComponentInfo{com.example.liveinbliss/com.example.liveinbliss.MainActivity}： java.lang.NullPointerException：尝试调用虚拟方法'void android.widget.Button.setOnClickListener(android.view.View$OnClickListener)' 在空对象引用上 在 android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2665) 在 android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2726) 在 android.app.ActivityThread.-wrap12(ActivityThread.java) 在 android.app.ActivityThread$H.handleMessage(ActivityThread.java:1477) 在 android.os.Handler.dispatchMessage(Handler.java:102) 在 android.os.Looper.loop(Looper.java:154) 在 android.app.ActivityThread.main(ActivityThread.java:6119) 在 java.lang.reflect.Method.invoke（本机方法） 在 com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:886) 在 com.android.internal.os.ZygoteInit.main(ZygoteInit.java:776) 引起：java.lang.NullPointerException：尝试调用虚拟方法'void android.widget.Button.setOnClickListener(android.view.View$OnClickListener)' 在空对象引用上 在 com.example.liveinbliss.MainActivity.onCreate(MainActivity.java:48) 在 android.app.Activity.performCreate(Activity.java:6679) 在 android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1118) 在 android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2618) 在 android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2726)

    at android.app.ActivityThread.-wrap12(ActivityThread.java) 
    at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1477) 
    at android.os.Handler.dispatchMessage(Handler.java:102) 
    at android.os.Looper.loop(Looper.java:154) 
    at android.app.ActivityThread.main(ActivityThread.java:6119) 
    at java.lang.reflect.Method.invoke(Native Method) 
    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:886)

    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:776)

Answer 1

试试这个：

public class MainActivity extends Activity implements SurfaceHolder.Callback {

    private MediaPlayer mp = null;

    SurfaceView mSurfaceView=null;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        mp = MediaPlayer.create(this, R.raw.perf); 
        mSurfaceView = (SurfaceView) findViewById(R.raw.introduction);
        mSurfaceView.getHolder().addCallback(this);


        mSurfaceView.getHolder().addCallback(this);

    @Override
    public void surfaceCreated(SurfaceHolder holder) {


        Uri video = Uri.parse("android.resource://" + getPackageName() + "/"
                + R.raw.introduction);

        try {
            mp.setDataSource(String.valueOf(video));
        } catch (IOException e) {
            e.printStackTrace();
        }
        try {
            mp.prepare();
        } catch (IOException e) {
            e.printStackTrace();
        }

        //Get the dimensions of the video
        int videoWidth = mp.getVideoWidth();
        int videoHeight = mp.getVideoHeight();

        //Get the width of the screen
        int screenWidth = getWindowManager().getDefaultDisplay().getWidth();

        //Get the SurfaceView layout parameters
        android.view.ViewGroup.LayoutParams lp = mSurfaceView.getLayoutParams();

        //Set the width of the SurfaceView to the width of the screen
        lp.width = screenWidth;

        //Set the height of the SurfaceView to match the aspect ratio of the video
        //be sure to cast these as floats otherwise the calculation will likely be 0
        lp.height = (int) (((float)videoHeight / (float)videoWidth) * (float)screenWidth);

        //Commit the layout parameters
        mSurfaceView.setLayoutParams(lp);

        //Start video
        mp.setDisplay(holder);
        mp.start();

        mp.setDisplay(holder);



    }

    @Override
    public void surfaceChanged(SurfaceHolder surfaceHolder, int i, int i1, int i2) {

    }

    @Override
    public void surfaceDestroyed(SurfaceHolder surfaceHolder) {

    }
}