Android学习-第47天

今天的任务为使用assets，代码如下：

Sound.java:

package com.bignerdranch.android.beatbox;

public class Sound {
    private String mAssetPath;
    private String mName;

    public Sound(String assetPath){
        mAssetPath=assetPath;
        String[] components=assetPath.split("/");
        String filename=components[components.length-1];
        mName=filename.replace(".wav","");
    }

    public String getAssetPath() {
        return mAssetPath;
    }

    public String getName() {
        return mName;
    }
}

BeatBox.java:

package com.bignerdranch.android.beatbox;

import android.content.Context;
import android.content.res.AssetManager;
import android.util.Log;

import java.io.IOException;
import java.util.ArrayList;
import java.util.List;

public class BeatBox {
    private static final String TAG="BeatBox";

    private static final String SOUNDS_FOLDER="sample_sounds";

    private AssetManager mAssets;
    private List<Sound> mSounds=new ArrayList<>();

    public BeatBox(Context context){
        mAssets=context.getAssets();
        loadSounds();
    }

    private void loadSounds() {
        String[] soundNames;
        try {
            soundNames=mAssets.list(SOUNDS_FOLDER);
            Log.i(TAG,"Found"+ soundNames.length+"sounds");
        }catch (IOException ioe){
            Log.e(TAG,"Could not list assets",ioe);
            return;
        }

        for (String filename : soundNames){
            String assetPath=SOUNDS_FOLDER+"/"+filename;
            Sound sound=new Sound(assetPath);
            mSounds.add(sound);
        }
    }

    public List<Sound> getSounds() {
        return mSounds;
    }
}

BeatBoxFragment.java:

package com.bignerdranch.android.beatbox;

import com.bignerdranch.android.beatbox.databinding.FragmentBeatBoxBinding;
import com.bignerdranch.android.beatbox.databinding.ListItemSoundBinding;

import android.databinding.DataBindingUtil;
import android.os.Bundle;
import android.support.annotation.NonNull;
import android.support.v4.app.Fragment;
import android.support.v7.widget.GridLayoutManager;
import android.support.v7.widget.RecyclerView;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;

import java.util.List;

public class BeatBoxFragment extends Fragment {
    private BeatBox mBeatBox;

    public static BeatBoxFragment newInstance(){
        return new BeatBoxFragment();
    }

    @Override
    public void onCreate(Bundle savedInstanceState){
        super.onCreate(savedInstanceState);

        mBeatBox=new BeatBox(getActivity());
    }

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
                            Bundle savedInstanceState){
        FragmentBeatBoxBinding binding= DataBindingUtil
                .inflate(inflater,R.layout.fragment_beat_box,container,false);

        binding.recyclerView.setLayoutManager(new GridLayoutManager(getActivity(),3));
        //binding.recyclerView.setAdapter(new SoundAdapter());
        binding.recyclerView.setAdapter(new SoundAdapter(mBeatBox.getSounds()));

        return binding.getRoot();
    }

    private class SoundHolder extends RecyclerView.ViewHolder{
        private ListItemSoundBinding mBinding;

        public SoundHolder(ListItemSoundBinding binding) {
            super(binding.getRoot());
            mBinding=binding;
        }
    }

    private class SoundAdapter extends RecyclerView.Adapter<SoundHolder>{
        private List<Sound> mSounds;

        public SoundAdapter(List<Sound> sounds){
            mSounds=sounds;
        }

        @Override
        public SoundHolder onCreateViewHolder(ViewGroup parent, int viewType) {
            LayoutInflater inflater=LayoutInflater.from(getActivity());
            ListItemSoundBinding binding=DataBindingUtil
                    .inflate(inflater,R.layout.list_item_sound,parent,false);
            return new SoundHolder(binding);
        }

        @Override
        public void onBindViewHolder(SoundHolder holder, int position) {

        }

        @Override
        public int getItemCount() {
            return mSounds.size();
        }
    }
}

截图如下：