Question

我正在开发一个音乐播放应用程序，但我一直坚持修复过去两天的错误。 Here is a screenshot of the app.基本上用户可以添加新视图，按照自己的意愿命名，并选择一个mp3文件链接到该视图。

正如您所看到的，每个视图都有一个带有一点播放图标的文本。播放音频时，此图标会切换为暂停图标。 Here you can see the pause icon.

问题1： 当用户启动声音然后点击另一个方块时，前一个声音停止，新声音开始，但旧方块的图标保持暂停图标，所以在屏幕上最终有很多方块会有暂停图标实际上并没有播放声音。

问题2：假设用户点击绝对第一个方块，其在arrayList中对应于位置0.然后用户向下滚动到他点击的方块不再可见的点。当用户再次向上滚动时，他点击的正方形将设置播放图标，同时播放声音。我想这是因为在我的GridAdapter中我设置了每个新显示的视图都有播放图标，我无法弄清楚如何设置if语句。适配器应该如何知道盒子播放声音？

非常感谢和爱。

GridItemAdapter.java：

public class GridItemAdapter extends ArrayAdapter<GridItem> {

    private static final String LOG_TAG = GridItemAdapter.class.getSimpleName();


    public GridItemAdapter(Activity context, ArrayList<GridItem> gridItems) {
        // Here, we initialize the ArrayAdapter's internal storage for the context and the list.
        // the second argument is used when the ArrayAdapter is populating a single TextView.
        // Because this is a custom adapter for two TextViews and an ImageView, the adapter is not
        // going to use this second argument, so it can be any value. Here, we used 0.
        super(context, 0, gridItems);
    }

    @Override
    public View getView(int position, View convertView, ViewGroup parent) {
        // Check if the existing view is being reused, otherwise inflate the view
        View gridItemView = convertView;
        if(gridItemView == null) {
            gridItemView = LayoutInflater.from(getContext()).inflate(
                    R.layout.grid_item, parent, false);
        }

        // Get the {@link AndroidFlavor} object located at this position in the list
        GridItem currentGridItem = getItem(position);

        // Find the TextView in the list_item.xml layout with the ID version_name
        TextView nameTextView = (TextView) gridItemView.findViewById(R.id.text_1);
        // set this text on the name TextView
        nameTextView.setText(currentGridItem.getSoundName());

        ImageView playIcon = (ImageView) gridItemView.findViewById(R.id.image_1);

        playIcon.setImageResource(R.drawable.play_ic);




        // Return the whole list item layout (containing 2 TextViews and an ImageView)
        // so that it can be shown in the ListView
        return gridItemView;
    }

}

感兴趣的MainActivity.java片段：

gridView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
            @Override
            public void onItemClick(AdapterView<?> adapterView, View view, int i, long l) {

            /*
            if (lastPosition != -1) {
                Log.v(TAG3, "Inisde if block, lastposition = " + lastPosition);
                // Whatever position you're looking for
                int firstPosition = gridView.getFirstVisiblePosition();
                int wantedChild = lastPosition - firstPosition;
                View wantedView = gridView.getChildAt(wantedChild);

                Log.v(TAG3, "lastRow initiated, lastrow = " + wantedView);
                ImageView lastIc = (ImageView) wantedView.findViewById(R.id.image_1);
                lastIc.setImageResource(R.drawable.play_ic);

            }
            */

            togglePlayback(i, view);
            lastPosition = i;
            Log.v(TAG3, "outside if block, lastPosition = " + lastPosition);
        }
    });

public void togglePlayback(int i, View v){
    final View view = v;

    if(!isPlaying) {
        releaseMediaPlayer();

        ImageView playIc = (ImageView) view.findViewById(R.id.image_1);
        playIc.setImageResource(R.drawable.pause_ic);
        GridItem word = gridItems.get(i);


        try {
            mMediaPlayer = MediaPlayer.create(MainActivity.this, Uri.parse(word.getSoundPath()));
        }catch (IllegalArgumentException e){
            e.printStackTrace();
        }
        mMediaPlayer.start();
        isPlaying = true;

        mMediaPlayer.setOnCompletionListener(new MediaPlayer.OnCompletionListener() {
            @Override
            public void onCompletion(MediaPlayer mediaPlayer) {
                releaseMediaPlayer();
                ImageView playIc = (ImageView) view.findViewById(R.id.image_1);
                playIc.setImageResource(R.drawable.play_ic);
                isPlaying = false;
            }
        });
    }else{
        releaseMediaPlayer();
        ImageView playIc = (ImageView) view.findViewById(R.id.image_1);
        playIc.setImageResource(R.drawable.play_ic);
        isPlaying = false;
    }



}

Answer 1

这是一种实现它的简单方法（由于尚未提供代码片段，我还没有完成您的代码，下面使用的变量是不言自明的）：

首先在gridview的项目的模型类中添加一个标记isPlaying
现在在getView方法中，添加以下代码

if(itemList.get(index).isPlaying) { //set the icon to pause one } else { //set the icon to playing one }
现在，在视图的点击监听器中，添加此

if(itemList.get(index).isPlaying) { // write the code to pause the current song } else { // pause your <previousIndex> song // play <index> item itemList.get(index).isPlaying = true; itemList.get(previousIndex).isPlaying = false; previousIndex = index; notifyDataSetChanged(); }

我刚刚编写了基本逻辑，你需要编写有关播放/暂停歌曲的代码。希望这会对你有所帮助。

单击GridLayout中的视图时，重置上次单击视图的图标

1 个答案: