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我正在使用 RecyclerView ('androidx.recyclerview:recyclerview:1.1.0') 和 Glide('com.github.bumptech.glide:glide:4.10.0')。

我想用RecyclerView. 每个视图持有者通过 Glide 加载图像。

加载所有图像后,我想通过调用滚动到底部scrollToPosition()
但就我而言,它不起作用。
它停留在第一行的位置。

问题:

问题

如果我使用override()Glide 的方法,它在我运行一次后就可以工作。
我猜是缓存。
但它在第一次发布时不起作用。

在职的:

在职的

如果我使用绝对高度作为ImageView,scolling工作。

以下是成功场景的摘要。

  1. wrap_content(ImageView) + override(x,y)(Glide) : 尝试一次后生效
  2. 固定高度(ImageView):它有效,但我想要固定宽度和动态高度并保持正确的比例

为了便于提问,我创建了一个新的简化项目。

我的代码如下。

activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout 
    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=".MainActivity">

    <androidx.recyclerview.widget.RecyclerView
        android:id="@+id/my_recycler_view"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:text="Hello World!"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintLeft_toLeftOf="parent"
        app:layout_constraintRight_toRightOf="parent"
        app:layout_constraintTop_toTopOf="parent" />

</androidx.constraintlayout.widget.ConstraintLayout>

my_image_view.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:orientation="vertical"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    >
    <ImageView
        android:id="@+id/imageView"
        android:layout_width="300dp"
        android:layout_height="wrap_content"
        android:layout_gravity="center"
        android:background="#FF3636"
        android:adjustViewBounds="true"/>
    <TextView
        android:id="@+id/textView"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_gravity="center"
        android:gravity="center"
        android:text="text"
        android:textSize="24dp"
        />
</LinearLayout>

MyAppGlideModule.java

import android.content.Context;

import com.bumptech.glide.Glide;
import com.bumptech.glide.Registry;
import com.bumptech.glide.annotation.GlideModule;
import com.bumptech.glide.module.AppGlideModule;
import com.firebase.ui.storage.images.FirebaseImageLoader;
import com.google.firebase.storage.StorageReference;
import java.io.InputStream;

@GlideModule
public class MyAppGlideModule extends AppGlideModule {
    @Override
    public void registerComponents(Context context, Glide glide, Registry registry) {
        // Register FirebaseImageLoader to handle StorageReference
        registry.append(StorageReference.class, InputStream.class,
                new FirebaseImageLoader.Factory());
    }
}

我的适配器.java

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

import androidx.recyclerview.widget.RecyclerView;

import com.google.firebase.storage.FirebaseStorage;
import com.google.firebase.storage.StorageReference;

public class MyAdapter extends RecyclerView.Adapter<MyAdapter.MyViewHolder> {
    private String[] mDataset;
    private Context mContext;

    public static class MyViewHolder extends RecyclerView.ViewHolder {
        public ImageView imageView;
        public TextView textView;
        public MyViewHolder(View v) {
            super(v);
            imageView = v.findViewById(R.id.imageView);
            textView = v.findViewById(R.id.textView);
        }
    }

    public MyAdapter(String[] myDataset) {
        mDataset = myDataset;
    }

    // Create new views (invoked by the layout manager)
    @Override
    public MyAdapter.MyViewHolder onCreateViewHolder(ViewGroup parent,
                                                     int viewType) {
        // create a new view
        View v = LayoutInflater.from(parent.getContext())
                .inflate(R.layout.my_image_view, parent, false);
        MyViewHolder vh = new MyViewHolder(v);
        mContext = parent.getContext();
        return vh;
    }

    // Replace the contents of a view (invoked by the layout manager)
    @Override
    public void onBindViewHolder(final MyViewHolder holder, int position) {
        holder.textView.setText(mDataset[position]);

        StorageReference mStorageRef;
        mStorageRef = FirebaseStorage.getInstance().getReference();

        StorageReference imageRef = mStorageRef.child("images/" + mDataset[position] +".jpg");

        GlideApp.with(mContext)
                .load(imageRef)
                .into(holder.imageView);

    }

    // Return the size of your dataset (invoked by the layout manager)
    @Override
    public int getItemCount() {
        return mDataset.length;
    }
}

MainActivity.java

import androidx.appcompat.app.AppCompatActivity;
import androidx.recyclerview.widget.LinearLayoutManager;
import androidx.recyclerview.widget.RecyclerView;

import android.os.Bundle;
import android.view.ViewGroup;


public class MainActivity extends AppCompatActivity {
    private RecyclerView recyclerView;
    private RecyclerView.Adapter mAdapter;
    private RecyclerView.LayoutManager layoutManager;

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

        recyclerView = findViewById(R.id.my_recycler_view);

        // use this setting to improve performance if you know that changes
        // in content do not change the layout size of the RecyclerView
        recyclerView.setHasFixedSize(true);

        // use a linear layout manager
        layoutManager = new LinearLayoutManager(this);
        recyclerView.setLayoutManager(layoutManager);

        String[] myDataset = {"1","2","3","4","5","6","7"};

        // specify an adapter (see also next example)
        mAdapter = new MyAdapter(myDataset);
        recyclerView.setAdapter(mAdapter);

        ViewGroup.LayoutParams layoutParams = recyclerView.getLayoutParams();

        recyclerView.scrollToPosition(myDataset.length - 1);
    }
}
4

1 回答 1

0

尝试放入layout_height="0dp"您的布局文件

<androidx.recyclerview.widget.RecyclerView
    android:id="@+id/my_recycler_view"
    android:layout_width="match_parent"
    android:layout_height="0dp"
    android:text="Hello World!"
    app:layout_constraintBottom_toBottomOf="parent"
    app:layout_constraintLeft_toLeftOf="parent"
    app:layout_constraintRight_toRightOf="parent"
    app:layout_constraintTop_toTopOf="parent" />
于 2020-06-22T17:30:04.130 回答