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：
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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 ArrayListpaths = 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{ private Context mContext; private OnItemClickLitener listener;//点击事件接口 private ArrayList 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 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"?>
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 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。
以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持创新互联。
