本文介绍了Android用RecyclerView实现动态添加本地图片，分享给大家，具体如下：
本文所用的多图选择的library来自：https://github.com/lovetuzitong/MultiImageSelector
简单介绍一下用法：
1、跳转到图片选择页面：
Intent intent = new Intent(PassengerSetActivity.this, MultiImageSelectorActivity.class);
intent.putExtra(MultiImageSelectorActivity.EXTRA_SHOW_CAMERA, true);
intent.putExtra(MultiImageSelectorActivity.EXTRA_SELECT_COUNT, 9);
intent.putExtra(MultiImageSelectorActivity.EXTRA_SELECT_MODE, MultiImageSelectorActivity.MODE_SINGLE);
startActivityForResult(intent, 10001);//10001-->添加
2、通过onActivityResult获取信息：
final ArrayList<String> paths = data.getStringArrayListExtra(MultiImageSelectorActivity.EXTRA_RESULT); Bitmap bitmap = BitmapFactory.decodeFile(paths.get(0), DIY_dialog.getBitmapOption(4));
首先设置布局管理器为：
recyclerview.setLayoutManager(new GridLayoutManager(this, 3));
然后设置适配器（这里在代码里面有详细的注释）：
public class PassengerAdapter extends RecyclerView.Adapter<PassengerAdapter.ViewHolder> {
private Context mContext;
private OnItemClickLitener listener;//点击事件接口
private ArrayList<String> imageUrls;
private ImageFetcher imageFetcher;
private ViewHolder viewHolder;
private View view;
/**
* 在构造方法中传入图片地址的数据
* @param context
* @param imageUrls
*/
public PassengerAdapter(Context context, ArrayList<String> imageUrls) {
this.mContext = context;
this.imageUrls = imageUrls;
//初始化加载网络图片的jar包
imageFetcher = new ImageFetcher(context);
imageFetcher.setImageCache(ImageCache.getInstance(context));
}
@Override
public ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
view = LayoutInflater.from(mContext).inflate(R.layout.lay_passager, null);
viewHolder = new ViewHolder(view);
return viewHolder;
}
@Override
public void onBindViewHolder(ViewHolder holder, int position) {
//设置内容为“hehe”的的元素为默认的添加按钮
if (imageUrls.get(position).equals("hehe")) {
holder.imageViewBig.setBackgroundResource(R.mipmap.add);
//当图片是添加按钮的时候隐藏删除按钮
holder.imageViewSmall.setVisibility(View.GONE);
} else {
holder.imageViewSmall.setVisibility(View.VISIBLE);
/**
* 判断图片路径是网络地址还是本地图片
* 设置路径之中包含“storage”的为本地图片
*/
if (imageUrls.get(position).contains("storage")) {
try {
File file = new File(imageUrls.get(position));
//将bitmap转化成drawable
Bitmap bmp = MediaStore.Images.Media.getBitmap(mContext.getContentResolver(), Uri.fromFile(file));
Drawable drawable =new BitmapDrawable(bmp);
//按比例扩大图片的size居中显示，使得图片长(宽)等于或大于View的长(宽)
holder.imageViewBig.setScaleType(ImageView.ScaleType.CENTER_CROP);
holder.imageViewBig.setImageBitmap(bmp);
} catch (IOException e) {
e.printStackTrace();
}
// holder.imageViewBig.setImageURI(Uri.parse(imageUrls.get(position)));
} else {
imageFetcher.loadImage(imageUrls.get(position), holder.imageViewBig, R.mipmap.touxiang);
}
}
}
@Override
public int getItemCount() {
return imageUrls.size();
}
public void setOnItemClickLitener(OnItemClickLitener listener) {
this.listener = listener;
}
public interface OnItemClickLitener {
void onBigClick(int position);
void onSmallClick(int position);
}
class ViewHolder extends RecyclerView.ViewHolder {
ImageView imageViewBig, imageViewSmall;
public ViewHolder(View itemView) {
super(itemView);
imageViewBig = (ImageView) itemView.findViewById(R.id.imageViewBig);
imageViewSmall = (ImageView) itemView.findViewById(R.id.imageViewSmall);
/**
*
* 因为元素是变化的，动态的，所以对点击事件的处理放在ViewHolder类里面，调用getposition()
* 可以获取到当前的元素位子
*/
imageViewBig.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
int position = (Integer) v.getTag();
listener.onBigClick(getPosition());
}
});
imageViewSmall.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
int position = (Integer) v.getTag();
listener.onSmallClick(getPosition());
}
});
}
}
}
recycler的布局文件
<?xml version="1.0" encoding="utf-8"?>
<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent">
<FrameLayout
android:id="@+id/lay_group"
android:layout_width="wrap_content"
android:layout_height="wrap_content">
<ImageView
android:id="@+id/imageViewBig"
android:layout_width="120dp"
android:layout_height="120dp"
android:background="@mipmap/background"
/>
<ImageView
android:id="@+id/imageViewSmall"
android:layout_width="20dp"
android:layout_height="20dp"
android:background="@mipmap/del"
android:layout_gravity="right"/>
</FrameLayout>
</FrameLayout>
配置recyclerview和设置点击事件
recyclerview = (RecyclerView) findViewById(R.id.recyclerview);
recyclerview.setLayoutManager(new GridLayoutManager(this, 3));
if(imageUrls.size()==0){
imageUrls.add("hehe");
}
passengerAdapter = new PassengerAdapter(this, imageUrls);
recyclerview.setAdapter(passengerAdapter);
passengerAdapter.setOnItemClickLitener(new PassengerAdapter.OnItemClickLitener() {
@Override
public void onBigClick(int position) {
Log.d(TAG, "onBigClick: "+passengerAdapter.getItemCount());
Log.d(TAG, "onBigClick: "+position);
if (position==imageUrls.size()-1) {
//添加本地相册图片，更新视图
Intent intent = new Intent(PassengerSetActivity.this, MultiImageSelectorActivity.class);
intent.putExtra(MultiImageSelectorActivity.EXTRA_SHOW_CAMERA, true);
intent.putExtra(MultiImageSelectorActivity.EXTRA_SELECT_COUNT, 9);
intent.putExtra(MultiImageSelectorActivity.EXTRA_SELECT_MODE, MultiImageSelectorActivity.MODE_SINGLE);
startActivityForResult(intent, 10001);//10001-->添加
} else {
Intent intent = new Intent(PassengerSetActivity.this, MultiImageSelectorActivity.class);
intent.putExtra(MultiImageSelectorActivity.EXTRA_SHOW_CAMERA, true);
intent.putExtra(MultiImageSelectorActivity.EXTRA_SELECT_COUNT, 9);
intent.putExtra(MultiImageSelectorActivity.EXTRA_SELECT_MODE, MultiImageSelectorActivity.MODE_SINGLE);
poss = position;
startActivityForResult(intent, 10002);//10002-->修改
//修改图片，更新视图
}
}
@Override
public void onSmallClick(int position) {
imageUrls.remove(position);
passengerAdapter.notifyItemRemoved(position);
//删除图片，更新视图
}
});
选择完图片后，进行ui更新的操作
/**
* 返回图片url,并上传七牛
*
* @param requestCode
* @param resultCode
* @param data
*/
@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
super.onActivityResult(requestCode, resultCode, data);
if(data!=null){
if (requestCode == 10001 || requestCode == 10002) {
final ArrayList<String> paths = data.getStringArrayListExtra(MultiImageSelectorActivity.EXTRA_RESULT);
Bitmap bitmap = BitmapFactory.decodeFile(paths.get(0), DIY_dialog.getBitmapOption(4));
//添加图片
if (requestCode == 10001) {
//将添加的图片放在第一位
imageUrls.add(0,paths.get(0));
//更新第一个位置的图片
passengerAdapter.notifyItemInserted(0);
}
//修改图片
else if (requestCode == 10002&&imageUrls.size()>0) {
int pos = poss;
imageUrls.set(pos,paths.get(0));
passengerAdapter.notifyItemChanged(pos);
}
}
}
}
大概就是这样了，简单的说一下思路，就是在存储图片的list的最后一项添加一个具有不同标识的数据，当点击时对应的标识和该标识一致，则添加，反之为修改。使用recylerview可以直接更新有变化的子项，而不用更新全部子项，用户体验更好，性能也提高了。
