Android 仿微信朋友圈添加图片

github地址（欢迎下载Demo）

https://github.com/zhouxu88/WXCircleAddPic

老习惯，先上图，着急用的朋友，直接带走Demo，先拿来用吧，毕竟老板催的紧，先把工作完成了，再看也来得及，是吧！

仿微信添加图片.gif

1、首先这是用GridView实现的

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:background="#fff"
    android:orientation="vertical">

    <!--展示上传的图片-->
    <GridView
        android:id="@+id/gridView"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_margin="15dp"
        android:columnWidth="60dp"
        android:horizontalSpacing="10dp"
        android:numColumns="auto_fit"
        android:verticalSpacing="10dp" />

</LinearLayout>

Adapter

package com.dearxy.wxcircleaddpic;

import android.content.Context;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ImageView;

import com.bumptech.glide.Glide;

import java.util.List;

/**
 * 展示上传的图片的GridView的适配器
 * <p>
 * 作者： 周旭 on 2017/6/21/0021.
 * 邮箱：374952705@qq.com
 * 博客：http://www.jianshu.com/u/56db5d78044d
 */

public class GridViewAdapter extends android.widget.BaseAdapter {

    private Context mContext;
    private List<String> mList;
    private LayoutInflater inflater;

    public GridViewAdapter(Context mContext, List<String> mList) {
        this.mContext = mContext;
        this.mList = mList;
        inflater = LayoutInflater.from(mContext);
    }

    @Override
    public int getCount() {
        //return mList.size() + 1;//因为最后多了一个添加图片的ImageView
        int count = mList == null ?  : mList.size() + ;
        if (count > MainConstant.MAX_SELECT_PIC_NUM) {
            return mList.size();
        } else {
            return count;
        }
    }

    @Override
    public Object getItem(int position) {
        return mList.get(position);
    }

    @Override
    public long getItemId(int position) {
        return position;
    }

    @Override
    public View getView(int position, View convertView, ViewGroup parent) {
        convertView = inflater.inflate(R.layout.grid_item, parent,false);
        ImageView iv = (ImageView) convertView.findViewById(R.id.pic_iv);
        if (position < mList.size()) {
         //代表+号之前的需要正常显示图片
            String picUrl = mList.get(position); //图片路径
            Glide.with(mContext).load(picUrl).into(iv);
        } else {
            iv.setImageResource(R.mipmap.zj);//最后一个显示加号图片
        }
        return convertView;
    }
}
MainActivity
/**
 * 仿微信朋友圈添加图片的效果
 */
public class MainActivity extends AppCompatActivity {

    private static final String TAG = "MainActivity";
    private Context mContext;
    private GridView gridView;
    private ArrayList<String> mPicList = new ArrayList<>(); //上传的图片凭证的数据源
    private GridViewAdapter mGridViewAddImgAdapter; //展示上传的图片的适配器

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        mContext = this;
        gridView = (GridView) findViewById(R.id.gridView);
        initGridView();
    }

    //初始化展示上传图片的GridView
    private void initGridView() {
        mGridViewAddImgAdapter = new GridViewAdapter(mContext, mPicList);
        gridView.setAdapter(mGridViewAddImgAdapter);
        gridView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
            @Override
            public void onItemClick(AdapterView<?> parent, View view,
                                    int position, long id) {
                if (position == parent.getChildCount() - ) {
                    //如果“增加按钮形状的”图片的位置是最后一张，且添加了的图片的数量不超过5张，才能点击
                    if (mPicList.size() == MainConstant.MAX_SELECT_PIC_NUM) {
                        //最多添加5张图片
                        viewPluImg(position);
                    } else {
                        //添加凭证图片
                        selectPic(MainConstant.MAX_SELECT_PIC_NUM - mPicList.size());
                    }
                } else {
                    viewPluImg(position);
                }
            }
        });
    }

    //查看大图
    private void viewPluImg(int position) {
        Intent intent = new Intent(mContext, PlusImageActivity.class);
        intent.putStringArrayListExtra(MainConstant.IMG_LIST, mPicList);
        intent.putExtra(MainConstant.POSITION, position);
        startActivityForResult(intent, MainConstant.REQUEST_CODE_MAIN);
    }

    /**
     * 打开相册或者照相机选择凭证图片，最多5张
     *
     * @param maxTotal 最多选择的图片的数量
     */
    private void selectPic(int maxTotal) {
        PictureSelectorConfig.initMultiConfig(this, maxTotal);
    }

    // 处理选择的照片的地址
    private void refreshAdapter(List<LocalMedia> picList) {
        for (LocalMedia localMedia : picList) {
            //被压缩后的图片路径
            if (localMedia.isCompressed()) {
                String compressPath = localMedia.getCompressPath(); //压缩后的图片路径
                mPicList.add(compressPath); //把图片添加到将要上传的图片数组中
                mGridViewAddImgAdapter.notifyDataSetChanged();
            }
        }
    }

    @Override
    protected void onActivityResult(int requestCode, int resultCode, Intent data) {
        super.onActivityResult(requestCode, resultCode, data);
        if (resultCode == RESULT_OK) {
            switch (requestCode) {
                case PictureConfig.CHOOSE_REQUEST:
                    // 图片选择结果回调
                    refreshAdapter(PictureSelector.obtainMultipleResult(data));
                    // 例如 LocalMedia 里面返回三种path
                    // 1.media.getPath(); 为原图path
                    // 2.media.getCutPath();为裁剪后path，需判断media.isCut();是否为true
                    // 3.media.getCompressPath();为压缩后path，需判断media.isCompressed();是否为true
                    // 如果裁剪并压缩了，以取压缩路径为准，因为是先裁剪后压缩的
                    break;
            }
        }
        if (requestCode == MainConstant.REQUEST_CODE_MAIN && resultCode == MainConstant.RESULT_CODE_VIEW_IMG) {
            //查看大图页面删除了图片
            ArrayList<String> toDeletePicList = data.getStringArrayListExtra(MainConstant.IMG_LIST); //要删除的图片的集合
            mPicList.clear();
            mPicList.addAll(toDeletePicList);
            mGridViewAddImgAdapter.notifyDataSetChanged();
        }
    }
}

总结：其实原理就是把数据的size+1,做为添加按钮的放置，然后判断下有9张图就不显示添加按钮，并且size也不+1，就这样，一个带添加按钮的GridView就好了~有什么不懂得可以留言。