移动应用开发写出相应的activity和xml文件1.布局简易多媒体界面，包括上半部分音频播放功能和下半部分的视频播放功能。 a)音频播放部分包括：音频路径输入控件、文件选择按钮、播放按钮、暂停按钮、重播按钮和停止按钮。 b)视频播放部分包括：视频路径输入控件、文件选择按钮、播放按钮和视频播放区的SurfaceView（适合大小）。分别建立三个activity，实现音频和视频播放功能，要求实现重播、暂停、停止、播放功能

好的，以下是相应的activity和xml文件，分别实现了音频播放、视频播放和音视频播放界面。

音频播放界面：

activity：

public class AudioPlayerActivity extends AppCompatActivity {
    private MediaPlayer mediaPlayer;
    private Button playButton;
    private Button pauseButton;
    private Button stopButton;
    private Button replayButton;
    private EditText pathEditText;

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

        pathEditText = findViewById(R.id.path_edit_text);
        playButton = findViewById(R.id.play_button);
        pauseButton = findViewById(R.id.pause_button);
        stopButton = findViewById(R.id.stop_button);
        replayButton = findViewById(R.id.replay_button);

        playButton.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                play();
            }
        });

        pauseButton.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                pause();
            }
        });

        stopButton.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                stop();
            }
        });

        replayButton.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                replay();
            }
        });
    }

    private void play() {
        try {
            if (mediaPlayer == null) {
                mediaPlayer = new MediaPlayer();
            }
            mediaPlayer.reset();
            mediaPlayer.setDataSource(pathEditText.getText().toString());
            mediaPlayer.prepare();
            mediaPlayer.start();
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    private void pause() {
        if (mediaPlayer != null && mediaPlayer.isPlaying()) {
            mediaPlayer.pause();
        }
    }

    private void stop() {
        if (mediaPlayer != null) {
            mediaPlayer.stop();
            mediaPlayer.release();
            mediaPlayer = null;
        }
    }

    private void replay() {
        if (mediaPlayer != null) {
            mediaPlayer.seekTo(0);
            mediaPlayer.start();
        }
    }
}

xml：

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:orientation="vertical"
    android:padding="20dp">

    <EditText
        android:id="@+id/path_edit_text"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:hint="请输入音频文件路径" />

    <Button
        android:id="@+id/play_button"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="播放" />

    <Button
        android:id="@+id/pause_button"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="暂停" />

    <Button
        android:id="@+id/stop_button"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="停止" />

    <Button
        android:id="@+id/replay_button"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="重播" />

</LinearLayout>

视频播放界面：

activity：

public class VideoPlayerActivity extends AppCompatActivity {
    private MediaPlayer mediaPlayer;
    private VideoView videoView;
    private EditText pathEditText;
    private Button playButton;

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

        pathEditText = findViewById(R.id.path_edit_text);
        playButton = findViewById(R.id.play_button);
        videoView = findViewById(R.id.video_view);

        playButton.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                play();
            }
        });
    }

    private void play() {
        videoView.setVideoPath(pathEditText.getText().toString());
        videoView.start();
    }
}

xml：

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:orientation="vertical"
    android:padding="20dp">

    <EditText
        android:id="@+id/path_edit_text"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:hint="请输入视频文件路径" />

    <Button
        android:id="@+id/play_button"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="播放" />

    <VideoView
        android:id="@+id/video_view"
        android:layout_width="match_parent"
        android:layout_height="match_parent" />

</LinearLayout>

音视频播放界面：

activity：

public class MediaPlayerActivity extends AppCompatActivity {
    private MediaPlayer mediaPlayer;
    private Button audioPlayButton;
    private Button audioPauseButton;
    private Button audioStopButton;
    private Button audioReplayButton;
    private EditText audioPathEditText;
    private VideoView videoView;
    private EditText videoPathEditText;
    private Button videoPlayButton;

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

        audioPathEditText = findViewById(R.id.audio_path_edit_text);
        audioPlayButton = findViewById(R.id.audio_play_button);
        audioPauseButton = findViewById(R.id.audio_pause_button);
        audioStopButton = findViewById(R.id.audio_stop_button);
        audioReplayButton = findViewById(R.id.audio_replay_button);

        videoPathEditText = findViewById(R.id.video_path_edit_text);
        videoPlayButton = findViewById(R.id.video_play_button);
        videoView = findViewById(R.id.video_view);

        audioPlayButton.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                playAudio();
            }
        });

        audioPauseButton.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                pauseAudio();
            }
        });

        audioStopButton.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                stopAudio();
            }
        });

        audioReplayButton.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                replayAudio();
            }
        });

        videoPlayButton.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                playVideo();
            }
        });
    }

    private void playAudio() {
        try {
            if (mediaPlayer == null) {
                mediaPlayer = new MediaPlayer();
            }
            mediaPlayer.reset();
            mediaPlayer.setDataSource(audioPathEditText.getText().toString());
            mediaPlayer.prepare();
            mediaPlayer.start();
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    private void pauseAudio() {
        if (mediaPlayer != null && mediaPlayer.isPlaying()) {
            mediaPlayer.pause();
        }
    }

    private void stopAudio() {
        if (mediaPlayer != null) {
            mediaPlayer.stop();
            mediaPlayer.release();
            mediaPlayer = null;
        }
    }

    private void replayAudio() {
        if (mediaPlayer != null) {
            mediaPlayer.seekTo(0);
            mediaPlayer.start();
        }
    }

    private void playVideo() {
        videoView.setVideoPath(videoPathEditText.getText().toString());
        videoView.start();
    }
}

xml：

<ScrollView xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent">

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:orientation="vertical"
        android:padding="20dp">

        <TextView
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:text="音频播放" />

        <EditText
            android:id="@+id/audio_path_edit_text"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:hint="请输入音频文件路径" />

        <Button
            android:id="@+id/audio_play_button"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:text="播放" />

        <Button
            android:id="@+id/audio_pause_button"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:text="暂停" />

        <Button
            android:id="@+id/audio_stop_button"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:text="停止" />

        <Button
            android:id="@+id/audio_replay_button"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:text="重播" />

        <TextView
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:text="视频播放" />

        <EditText
            android:id="@+id/video_path_edit_text"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:hint="请输入视频文件路径" />

        <Button
            android:id="@+id/video_play_button"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:text="播放" />

        <VideoView
            android:id="@+id/video_view"
            android:layout_width="match_parent"
            android:layout_height="wrap_content" />

    </LinearLayout>

</ScrollView>