我正在创建一个应用程序，显示RecyclerView中的一些漂亮女孩，当滚动到底部时负载更多。我遇到了一些问题，您可以在videos link here.
或者：
予。添加更多项目时，它只显示一列而不是所有定义的3列。
II。向上滚动时，所有子视图都在快速移动，然后RecyclerView将我带到顶部并跳过所有项目。示例：当前项目为100并向上滚动，您站在列表顶部几毫秒。
我的项目有：
build.grade: compile 'com.android.support:recyclerview-v7:23.4.0'：由于JDK版本，我不想将RecyclerView更新为24。MainActivity扩展了AppCompatActivity：
public class MainActivity extends AppCompatActivity {
private RelativeLayout rootView;
private RecyclerView mRecyclerView;
private StaggeredGridLayoutManager mLayoutManager;
private ImagesAdapter mAdapter;
private Handler mHandler;
private int currentOffset;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
currentOffset = 0;
loading = true;
mHandler = new Handler(getMainLooper());
initRetrofit();
initWidget();
fetchingData(true);
}
private void initRetrofit() {
Gson gson = new GsonBuilder().disableHtmlEscaping().create();
OkHttpClient.Builder builderHttpClient = new OkHttpClient.Builder();
//builderHttpClient.interceptors().add(new LoggingInterceptor());
OkHttpClient client = builderHttpClient.build();
NetworkManager.init(new Retrofit.Builder().baseUrl(APIConfig.BASE_URL).addConverterFactory(new ToStringConverterFactory()).addConverterFactory(GsonConverterFactory.create(gson)).client(client).build());
}
private void initWidget() {
mRecyclerView = (RecyclerView) findViewById(R.id.rv_main);
mLayoutManager = new StaggeredGridLayoutManager(3, StaggeredGridLayoutManager.VERTICAL);
mAdapter = new ImagesAdapter(this, new ArrayList<PhotoItemModel>());
mRecyclerView.setLayoutManager(mLayoutManager);
mRecyclerView.addItemDecoration(new SpacesItemDecoration(15));
mRecyclerView.setAdapter(mAdapter);
mRecyclerView.addOnScrollListener(new RecyclerView.OnScrollListener() {
@Override
public void onScrolled(RecyclerView recyclerView, int dx, int dy) {
if (dy > 0) //check for scroll down
{
visibleItemCount = mLayoutManager.getChildCount();
totalItemCount = mLayoutManager.getItemCount();
int[] items = mLayoutManager.findFirstCompletelyVisibleItemPositions(null);
if (items.length > 0) {
pastVisibleItems = items[0];
}
if (loading) {
if ((visibleItemCount + pastVisibleItems) >= totalItemCount) {
loading = false;
fetchingData();
}
}
}
}
});
}
private void fetchingData() {
currentOffset = mAdapter.getItemCount();
mHandler.postDelayed(new Runnable() {
@Override
public void run() {
NetworkManager.getPhotoByOffset(currentOffset, new Callback<GetPhotoResponse>() {
@Override
public void onResponse(Call<GetPhotoResponse> call, retrofit2.Response<GetPhotoResponse> response) {
if (null != response && null != response.body()) {
ResponseModel responseModel = response.body().getResponseModel();
List<PostItemModel> postItemModels = responseModel.getPostItemModels();
List<PhotoItemModel> photoItemModels = new ArrayList<>();
for (PostItemModel postItemModel : postItemModels) {
photoItemModels.addAll(postItemModel.getPhotos());
}
mAdapter.insertMoreItems(photoItemModels);
loading = true;
} else {
loading = true;
fetchingData();
}
}
@Override
public void onFailure(Call<GetPhotoResponse> call, Throwable t) {
t.printStackTrace();
loading = true;
fetchingData();
}
});
}
}, 5000);
}
}
适配器：
public class ImagesAdapter extends RecyclerView.Adapter<VHImage> {
private MainActivity mainActivity;
private List<PhotoItemModel> photoItemModels;
public ImagesAdapter(MainActivity mainActivity, ArrayList<PhotoItemModel> photoItemModels) {
this.mainActivity = mainActivity;
this.photoItemModels = photoItemModels;
}
public List<PhotoItemModel> getPhotoItemModels() {
return photoItemModels;
}
@Override
public VHImage onCreateViewHolder(ViewGroup parent, int viewType) {
View view = LayoutInflater.from(parent.getContext()).inflate(R.layout.item_image, parent, false);
return new VHImage(mainActivity, view);
}
@Override
public void onBindViewHolder(VHImage holder, int position) {
holder.bindData(photoItemModels.get(position));
}
@Override
public int getItemCount() {
return photoItemModels.size();
}
public void insertMoreItems(List<PhotoItemModel> morePhotoItemModels) {
int oldSize = photoItemModels.size();
photoItemModels.addAll(morePhotoItemModels);
notifyItemRangeInserted(oldSize, morePhotoItemModels.size());
}
}
ViewHolder
public class VHImage extends RecyclerView.ViewHolder implements View.OnClickListener {
private MainActivity mainActivity;
private ImageView ivImage;
private View div1, div2;
private PhotoItemModel photoItemModel;
public VHImage(MainActivity mainActivity, View itemView) {
super(itemView);
this.mainActivity = mainActivity;
ivImage = (ImageView) itemView.findViewById(R.id.iv_image);
div1 = itemView.findViewById(R.id.v_div_1);
div2 = itemView.findViewById(R.id.v_div_2);
ivImage.setOnClickListener(this);
}
public void bindData(PhotoItemModel photoItemModel) {
this.photoItemModel = photoItemModel;
Glide.with(mainActivity.getApplicationContext())
.load(photoItemModel.getAltSizesList().get(2).getUrl())
.diskCacheStrategy(DiskCacheStrategy.RESULT)
.listener(new RequestListener<String, GlideDrawable>() {
@Override
public boolean onException(Exception e, String model, Target<GlideDrawable> target, boolean isFirstResource) {
div1.setVisibility(View.INVISIBLE);
div2.setVisibility(View.INVISIBLE);
return false;
}
@Override
public boolean onResourceReady(GlideDrawable resource, String model, Target<GlideDrawable> target, boolean isFromMemoryCache, boolean isFirstResource) {
div1.setVisibility(View.VISIBLE);
div2.setVisibility(View.VISIBLE);
return false;
}
})
.into(ivImage);
}
@Override
public void onClick(View view) {
mainActivity.onImageClick(view, ((ImageView) view).getDrawable(), photoItemModel);
}
}
活动布局
<android.support.v7.widget.RecyclerView
android:id="@+id/rv_main"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:padding="0.5dp"
android:visibility="invisible" />
<ImageView
android:id="@+id/iv_full_screen"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:adjustViewBounds="true"
android:scaleType="fitCenter"
android:visibility="invisible" />
<ImageView
android:id="@+id/iv_splash1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_centerInParent="true"
android:adjustViewBounds="true"
android:scaleType="fitCenter"
android:visibility="gone" />
<ImageView
android:id="@+id/iv_splash2"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_centerInParent="true"
android:adjustViewBounds="true"
android:scaleType="fitCenter"
android:visibility="gone" />
<ProgressBar
android:id="@+id/pb_loading"
style="?android:attr/progressBarStyleHorizontal"
android:layout_width="200dp"
android:layout_height="wrap_content"
android:layout_below="@+id/iv_splash1"
android:layout_centerHorizontal="true"
android:layout_gravity="bottom"
android:layout_marginBottom="3dp"
android:layout_marginTop="20dp"
android:indeterminate="true"
android:max="1000"
android:progressDrawable="@drawable/progress_drawable" />
项目布局
<View
android:id="@+id/v_div_1"
android:layout_width="match_parent"
android:layout_height="1dp"
android:layout_marginLeft="10dp"
android:layout_marginRight="10dp"
android:background="#000000"
android:visibility="invisible" />
<View
android:id="@+id/v_div_2"
android:layout_width="match_parent"
android:layout_height="1dp"
android:layout_marginLeft="5dp"
android:layout_marginRight="5dp"
android:layout_marginTop="0.5dp"
android:background="#000000"
android:visibility="invisible" />
<ImageView
android:id="@+id/iv_image"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_marginTop="0.5dp"
android:adjustViewBounds="true" />
答案 0 :(得分：0)
在下载图片之前，除非您从网络服务发送图像尺寸并在显示之前设置ImageView高度，否则无法找到图像。
例如，您的网络服务响应可能是这样的：
{
"ImageLink" = "http://www.example.com/example.jpg"
"ImageWidth" = 1024
"ImageHeight" = 768
}
然后将ImageView大小设置为：
imageview.getLayoutParams().height = imageview.getWidth() * (ImageHeight/ImageWidth);
为了获得更好的性能，请在将ImageView布局大小添加到RecyclerView之前设置它。