Fresco加载手机图片墙

//网络权限

 <uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" />
 <uses-permission android:name="android.permission.INTERNET" />

//添加依赖

compile 'com.android.support:appcompat-v7:26.+'
compile 'com.android.support.constraint:constraint-layout:1.0.2'
compile 'com.android.support:recyclerview-v7:26.0.0-alpha1'
compile 'com.squareup.retrofit2:retrofit:2.0.0-beta4'
compile 'com.facebook.fresco:fresco:0.12.0'
testCompile 'junit:junit:4.12'

布局文件

activity_main

"http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools" android:layout_width="match_parent"
    android:layout_height="match_parent" tools:context="com.spl.dell.fresco_photowall.MainActivity">

    .support.v7.widget.RecyclerView
        android:id="@+id/main_recycler"
        android:layout_width="match_parent"
        android:layout_height="match_parent">.support.v7.widget.RecyclerView>

activity_zoom_image

"http://schemas.android.com/apk/res-auto"
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context="com.spl.dell.fresco_photowall.ZoomImageActivity">

    <com.facebook.drawee.view.SimpleDraweeView
        android:id="@+id/img_sdv"
        android:background="@mipmap/ic_launcher"
        android:layout_centerInParent="true"
        android:layout_width="400dp"
        android:layout_height="400dp" />

fresco_item

"http://schemas.android.com/apk/res/android"
    xmlns:fresco="http://schemas.android.com/apk/res-auto"
    android:orientation="vertical" android:layout_width="match_parent"
    android:layout_height="match_parent">

    <com.facebook.drawee.view.SimpleDraweeView
        android:id="@+id/sdv"
        android:layout_marginLeft="35dp"
        android:layout_width="100dp"
        android:layout_height="100dp"
        fresco:placeholderImage="@drawable/icon_placeholder"
        fresco:placeholderImageScaleType="fitCenter"

        fresco:progressBarImage="@drawable/icon_progress_bar"
        fresco:progressBarImageScaleType="centerInside"
        fresco:progressBarAutoRotateInterval="5000"

        fresco:failureImage="@drawable/icon_failure"
        fresco:failureImageScaleType="centerInside"

        fresco:retryImage="@drawable/icon_retry"
        fresco:retryImageScaleType="centerCrop"
        />

MyViewHolder

import android.support.v7.widget.RecyclerView;
import android.view.View;

import com.facebook.drawee.view.SimpleDraweeView;
import com.spl.dell.fresco_photowall.R;

/**
 * Created by dell on 2018/3/8.
 */

public class MyViewHolder extends RecyclerView.ViewHolder {

    public SimpleDraweeView simpleDraweeView;

    public MyViewHolder(View itemView) {
        super(itemView);
        simpleDraweeView = itemView.findViewById(R.id.sdv);
    }
}

MyRecyclerViewAdapter

import android.content.Context;
import android.net.Uri;
import android.support.v7.widget.RecyclerView;
import android.view.View;
import android.view.ViewGroup;

import com.spl.dell.fresco_photowall.R;
import com.spl.dell.fresco_photowall.recyclerview_adapter.viewholder.MyViewHolder;

import java.io.File;
import java.util.List;

/**
 * Created by dell on 2018/3/8.
 */

public class MyRecyclerViewAdapter extends RecyclerView.Adapter<MyViewHolder> {

    Context context;
    List list;

    public MyRecyclerViewAdapter(Context context, List list) {
        this.context = context;
        this.list = list;
    }

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

    @Override
    public void onBindViewHolder(MyViewHolder holder, final int position) {
        Uri uri = Uri.fromFile(new File(list.get(position)));
        holder.simpleDraweeView.setImageURI(uri);


        holder.simpleDraweeView.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                onRecyclerItemClick.onItemClicklistener(position);
            }
        });
    }

    public void setOnItemClick(onRecyclerItemClick onRecyclerItemClick){
        this.onRecyclerItemClick = onRecyclerItemClick;
    }

    @Override
    public int getItemCount() {
        return list.size();
    }
    onRecyclerItemClick onRecyclerItemClick;
    public interface onRecyclerItemClick{
        void onItemClicklistener(int position);
    }

}

MyApp

import android.app.Application;

import com.facebook.drawee.backends.pipeline.Fresco;

/**
 * Created by dell on 2018/3/8.
 */

public class MyApp extends Application {
    @Override
    public void onCreate() {
        super.onCreate();
        Fresco.initialize(this);
    }
}

ZoomImageActivity

import android.content.Intent;
import android.net.Uri;
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;

import com.facebook.drawee.view.SimpleDraweeView;

import java.io.File;

public class ZoomImageActivity extends AppCompatActivity {

    private SimpleDraweeView sdv;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        getSupportActionBar().hide();
        setContentView(R.layout.activity_zoom_image);
        Intent intent = getIntent();
        String imgurl = intent.getStringExtra("imgurl");
        Uri uri = Uri.fromFile(new File(imgurl));
        sdv = (SimpleDraweeView) findViewById(R.id.img_sdv);
        sdv.setImageURI(uri);
    }
}

MainActivity

import android.content.Intent;
import android.database.Cursor;
import android.os.Bundle;
import android.provider.MediaStore;
import android.support.v7.app.AppCompatActivity;
import android.support.v7.widget.GridLayoutManager;
import android.support.v7.widget.OrientationHelper;
import android.support.v7.widget.RecyclerView;

import com.spl.dell.fresco_photowall.recyclerview_adapter.MyRecyclerViewAdapter;

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

public class MainActivity extends AppCompatActivity {

    private RecyclerView recycler;
    private List docs = new ArrayList<>();

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        getSupportActionBar().hide();
        setContentView(R.layout.activity_main);
        initView();
        //recyclerview的数据源需要从手机相册中获取
        initData();
    }

    private void initData() {

        Cursor cursor = getContentResolver().query(MediaStore.Images.Media.EXTERNAL_CONTENT_URI, null, null, null, null);
        while(cursor.moveToNext()){
            String paths = cursor.getString(cursor.getColumnIndex(MediaStore.Images.Media.DATA));
            File file = new File(paths);
            String absolutePath = file.getAbsolutePath();
            docs.add(absolutePath);
        }
        cursor.close();

//        for(int i = 0;i
//            Log.d("TAG",docs.get(i).toString());
//        }

        runOnUiThread(new Runnable() {
            @Override
            public void run() {
                MyRecyclerViewAdapter adapter = new MyRecyclerViewAdapter(MainActivity.this,docs);
                recycler.setAdapter(adapter);

                adapter.setOnItemClick(new MyRecyclerViewAdapter.onRecyclerItemClick() {
                    @Override
                    public void onItemClicklistener(int position) {
                        Intent intent = new Intent(MainActivity.this,ZoomImageActivity.class);
                        intent.putExtra("imgurl",docs.get(position));
                        startActivity(intent);
                    }
                });
            }
        });
    }

    private void initView() {
        recycler = (RecyclerView) findViewById(R.id.main_recycler);
        RecyclerView.LayoutManager manager = new GridLayoutManager(MainActivity.this,3 ,OrientationHelper.VERTICAL,false);
        recycler.setLayoutManager(manager);
    }
}