我想显示在搜索栏中播放的音乐的进度

Question

我想显示在搜索栏中播放音乐的进度。我不能这样做。请帮忙！
我不明白这里有什么问题。我对编程非常陌生。我实际上正在尝试构建一个可以播放音乐的应用程序，并且音乐进度显示在搜索栏上

package com.example.musicapp;
import androidx.appcompat.app.AppCompatActivity;

import android.media.MediaPlayer;
import android.os.Bundle;
import android.os.Handler;
import android.provider.MediaStore;
import android.view.View;
import android.widget.ImageButton;
import android.widget.SeekBar;
import android.widget.Toast;


public class MainActivity extends AppCompatActivity {
MediaPlayer startmusic;
SeekBar seekBar;
ImageButton play;
ImageButton pause;
    Handler handler;
    Runnable runnable;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        play=findViewById(R.id.play_button);
        seekBar=findViewById(R.id.seekBar);
        pause=findViewById(R.id.pause_button);
startmusic=MediaPlayer.create(this,R.raw.music);
    }
public void playmusic(View v){
        startmusic.start();
        play.setImageResource(R.drawable.pause);
                play.setVisibility(play.GONE);
                pause.setVisibility(pause.VISIBLE);
                seekBar.setMax(startmusic.getDuration());
    Toast toast=Toast.makeText(getApplicationContext(),"Music is playing", Toast.LENGTH_SHORT);
    toast.show();
    changeSeekbar();
}

    private void changeSeekbar() {
        if(startmusic.isPlaying()){
            seekBar.setProgress(startmusic.getCurrentPosition());
            runnable=new Runnable() {
                @Override
                public void run() {
                changeSeekbar();
                    handler.postDelayed(runnable,100);
                }
            };

        }

    }

    public void pausemusic(View v){
        if(startmusic.isPlaying()) {
            startmusic.pause();
            play.setImageResource(R.drawable.pause);
            play.setVisibility(play.VISIBLE);
            pause.setVisibility(pause.GONE);
            seekBar.setProgress(startmusic.getCurrentPosition());
            Toast toast=Toast.makeText(getApplicationContext(),"Music is paused", Toast.LENGTH_SHORT);
            toast.show();
        }
    }

        }

Answer 1

您可以使用 MediaPlayer 类的常用方法来显示进度：

• 开始()
• 停止()
• release() – 防止内存泄漏。
• seekTo(position) – 这将与 SeekBar 一起使用
• isPlaying() - 让我们知道歌曲是否正在播放。
• getDuration() – 用于获取总持续时间。使用它，我们将 知道我们 SeekBar 的上限。该函数返回 持续时间（毫秒）
• setDataSource(FileDescriptor fd) - 用于设置要播放的文件。

• setVolume(float leftVolume, float rightVolume) - 用于设置 音量级别。该值是介于 0 或 1 之间的浮点数。

  <SeekBar
      android:id="@+id/seekbar"
      android:layout_margin="16dp"
      android:layout_width="match_parent"
      android:layout_height="wrap_content"
      android:layout_gravity="center" />
  

MainActivity.java 类的代码如下：

public class MainActivity extends AppCompatActivity implements Runnable {
    MediaPlayer startmusic;
    SeekBar seekBar;
    ImageButton play;
    ImageButton pause;
    Handler handler;
    Runnable runnable;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        play=findViewById(R.id.play_button);
        seekBar=findViewById(R.id.seekBar);
        pause=findViewById(R.id.pause_button);
        startmusic=MediaPlayer.create(this,R.raw.music);

        seekBar.setOnSeekBarChangeListener(new SeekBar.OnSeekBarChangeListener() {
            @Override
            public void onStartTrackingTouch(SeekBar seekBar) {

                seekBarHint.setVisibility(View.VISIBLE);
            }

            @Override
            public void onProgressChanged(SeekBar seekBar, int progress, boolean fromTouch) {
                seekBarHint.setVisibility(View.VISIBLE);
                int x = (int) Math.ceil(progress / 1000f);

                if (x == 0 && startmusic != null && !startmusic.isPlaying()) {
                    clearMediaPlayer();
                    MainActivity.this.seekBar.setProgress(0);
                }

            }

            @Override
            public void onStopTrackingTouch(SeekBar seekBar) {

                if (startmusic != null && startmusic.isPlaying()) {
                    startmusic.seekTo(seekBar.getProgress());
                }
            }
        });

    }

    //its look that you call this method form layout itself
    //change your play method defination to 
    public void playmusic(View v) {

      try {
        play.setImageResource(R.drawable.pause);
        play.setVisibility(play.GONE);
        pause.setVisibility(pause.VISIBLE);
        Toast toast=Toast.makeText(getApplicationContext(),"Music is playing", Toast.LENGTH_SHORT);
        toast.show();

                if (startmusic == null) {
                    startmusic = new MediaPlayer();
                }


                AssetFileDescriptor afd = context.getResources().openRawResourceFd(/*your raw id resource*/);
                if (afd == null)
                 return;
                startmusic.setDataSource(afd.getFileDescriptor(), afd.getStartOffset(), afd.getLength());
                afd.close();

                startmusic.prepare();
                startmusic.setVolume(0.5f, 0.5f);
                startmusic.setLooping(false);
                seekBar.setMax(startmusic.getDuration());

                startmusic.start();
                new Thread(this).start();
        } catch (Exception e) {
            e.printStackTrace();

        }
}

    public void pausemusic(View v) {
        //add null check
        if(startmusic != null && startmusic.isPlaying()) {
            startmusic.pause();
            play.setImageResource(R.drawable.pause);
            play.setVisibility(play.VISIBLE);
            pause.setVisibility(pause.GONE);
            seekBar.setProgress(startmusic.getCurrentPosition());
            Toast toast=Toast.makeText(getApplicationContext(),"Music is paused", Toast.LENGTH_SHORT);
            toast.show();
        }
    }

    public void run() {

        int currentPosition = startmusic.getCurrentPosition();
        int total = startmusic.getDuration();

        if (currentPosition == total) {
            clearMediaPlayer();
        }


        while (startmusic != null && startmusic.isPlaying() && currentPosition < total) {
            try {
                Thread.sleep(1000);
                currentPosition = startmusic.getCurrentPosition();
            } catch (InterruptedException e) {
                return;
            } catch (Exception e) {
                return;
            }

            seekBar.setProgress(currentPosition);

        }
    }

    @Override
    protected void onDestroy() {
        super.onDestroy();
        clearMediaPlayer();
    }

    private void clearMediaPlayer() {
        startmusic.stop();
        startmusic.release();
        startmusic = null;
    }

}