MVP+RXJAVA+RecyclerView实现sd卡根目录下的所有文件中的照片加载并显示

public interface IImgsView {

    void onImgsLoadCompleted(ArrayList<String> imgs);
}


public interface IImgsPresenter {
    void getImages(File[] files);
}

package com.create.qdocumentimtest.rxjavatest.view;

import android.os.Bundle;
import android.os.Environment;
import android.support.v7.app.AppCompatActivity;
import android.support.v7.widget.RecyclerView;
import android.support.v7.widget.StaggeredGridLayoutManager;

import com.create.qdocumentimtest.R;
import com.create.qdocumentimtest.rxjavatest.adapter.MyRecyRxAdapter;
import com.create.qdocumentimtest.rxjavatest.presenter.IImgsPresenter;
import com.create.qdocumentimtest.rxjavatest.presenter.ImgPresenterCompl;

import java.io.File;
import java.util.ArrayList;

import butterknife.ButterKnife;
import butterknife.InjectView;

/**
 * 功能：使用mvp  rxjava完成sd卡根目录中的所有子目录中的图片的加载，在recyclerView中以瀑布流形式显示。
 */
public class ThreeActivity extends AppCompatActivity implements IImgsView {
    @InjectView(R.id.recyclerView)
    RecyclerView recyclerView;
    private String basePath;
    private IImgsPresenter imgsPresenter;
    private ArrayList<String> imgs = new ArrayList<>();

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_three);
        ButterKnife.inject(this);
        imgsPresenter = new ImgPresenterCompl(this);
        basePath = Environment.getExternalStorageDirectory().getPath();
        File file = new File(basePath);
        File[] files = file.listFiles();
        imgsPresenter.getImages(files);
    }

    @Override
    public void onImgsLoadCompleted(ArrayList<String> imgs) {//presenter加载完资源后回调
        recyclerView.setLayoutManager(new StaggeredGridLayoutManager(3,StaggeredGridLayoutManager.VERTICAL));
        MyRecyRxAdapter adapter=new MyRecyRxAdapter(this,imgs);
        recyclerView.setAdapter(adapter);
    }
}

package com.create.qdocumentimtest.rxjavatest.presenter;


import android.util.Log;

import com.create.qdocumentimtest.rxjavatest.view.IImgsView;

import java.io.File;
import java.util.ArrayList;

import rx.Observable;
import rx.Subscriber;
import rx.android.schedulers.AndroidSchedulers;
import rx.functions.Func1;
import rx.schedulers.Schedulers;

/**
 * Created by Administrator on 2016/6/8 0008.
 */
public class ImgPresenterCompl implements IImgsPresenter {
    private IImgsView imgsView;
    private ArrayList<String> imgs=new ArrayList<>();
    public ImgPresenterCompl(IImgsView imgsView) {
        this.imgsView=imgsView;
    }
    @Override
    public void getImages(File[] files) {
        Observable.from(files)
                .filter(new Func1<File, Boolean>() {//过滤文件夹，只选择文件夹，不选择其他文件（即便有图片也没法选择了）
                    @Override
                    public Boolean call(File file) {
                        return file.isDirectory();
                    }
                })
                .flatMap(new Func1<File, Observable<File>>() {
                    @Override
                    public Observable<File> call(File file) {//遍历文件夹
                        return Observable.from(file.listFiles());
                    }
                })
                .filter(new Func1<File, Boolean>() {//过滤图片，二级文件夹中的图片无法找出
                    @Override
                    public Boolean call(File file) {
                        return file.getName().endsWith(".png")||file.getName().endsWith(".jpg")||file.getName().endsWith(".jpeg");
                    }
                })
                .map(new Func1<File, String>() {
                    @Override
                    public String call(File file) {
                        return file.getPath();
                    }
                })
                .subscribeOn(Schedulers.io())
                .observeOn(AndroidSchedulers.mainThread())
                 .subscribe(new Subscriber<String>() {
                     @Override
                     public void onCompleted() {//onnext（）执行完后调用
                         Log.e("img","完成");
                      imgsView.onImgsLoadCompleted(imgs);
                     }
                     @Override
                     public void onError(Throwable e) {
                     }
                     @Override
                     public void onNext(String s) {
                         Log.e("img",s);
                         imgs.add(s);
                     }
                 });
    }
}

package com.create.qdocumentimtest.rxjavatest.adapter;

import android.content.Context;
import android.support.v7.widget.RecyclerView;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ImageView;
import android.widget.LinearLayout;

import com.bumptech.glide.Glide;
import com.create.qdocumentimtest.R;
import com.create.qdocumentimtest.rxjavatest.utils.Dp2pxUtils;
import com.create.qdocumentimtest.rxjavatest.utils.ImgUtils;
import com.create.qdocumentimtest.rxjavatest.utils.ScreenUtil;

import java.util.ArrayList;
import java.util.List;

import butterknife.ButterKnife;
import butterknife.InjectView;

/**
 * Created by Administrator on 2016/6/8 0008.
 */
public class MyRecyRxAdapter extends RecyclerView.Adapter<MyRecyRxAdapter.MyViewHolder>{
    private Context context;
    List<String> imgs;
    public MyRecyRxAdapter(Context context, ArrayList<String> imgs) {
        this.context = context;
        this.imgs=imgs;
    }

    @Override
    public MyViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
        View itemView=View.inflate(context, R.layout.item_recycle_rxjava_layout,null);
        MyViewHolder vh=new MyViewHolder(itemView);
        return vh;
    }

    @Override
    public void onBindViewHolder(MyViewHolder holder, int position) {
        int showImageHeight = getShowImageHeight(position);

        LinearLayout.LayoutParams params = (LinearLayout.LayoutParams) holder.imageView.getLayoutParams();

        params.height=showImageHeight;
        holder.imageView.setLayoutParams(params);
        Glide.with(context).load(imgs.get(position)).into(holder.imageView);
        //高度设置
    }

    /**
     * 获取条目高度
     * @param position
     * @return
     */
    private int getShowImageHeight(int position) {
        int width= ScreenUtil.getScreenWidth(context);
        int height=ScreenUtil.getScreenHight(context);
        int px= Dp2pxUtils.Dp2Px(context, 6);
        int viewWidth = width / 3 - px;
        int originalWidth = ImgUtils.getImgOriginalWidth(imgs.get(position));
        int originalHeight = ImgUtils.getImgOriginalHeight(imgs.get(position));
        return originalHeight * viewWidth / originalWidth;
    }

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

    class MyViewHolder extends RecyclerView.ViewHolder{
        ImageView imageView;
        public MyViewHolder(View itemView) {
            super(itemView);
            imageView= (ImageView) itemView.findViewById(R.id.image);
        }
    }
}