Android GlideApp FixedPreloadSizeProvider RecyclerViewPreloader preload scroll smooth，Java
<uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" />
<uses-permission android:name="android.permission.READ_MEDIA_IMAGES" />
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
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/recycler_view"
android:layout_width="match_parent"
android:layout_height="match_parent" />
</RelativeLayout>
import androidx.annotation.NonNull;
import androidx.annotation.Nullable;
import androidx.appcompat.app.AppCompatActivity;
import androidx.appcompat.widget.AppCompatImageView;
import androidx.recyclerview.widget.GridLayoutManager;
import androidx.recyclerview.widget.RecyclerView;
import android.content.Context;
import android.database.Cursor;
import android.graphics.drawable.Drawable;
import android.os.Bundle;
import android.provider.MediaStore;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.TextView;
import com.bumptech.glide.ListPreloader;
import com.bumptech.glide.RequestBuilder;
import com.bumptech.glide.integration.recyclerview.RecyclerViewPreloader;
import com.bumptech.glide.util.FixedPreloadSizeProvider;
import java.io.File;
import java.util.ArrayList;
import java.util.List;
public class MainActivity extends AppCompatActivity {
private GlideRequest<Drawable> fullRequest = null;
private GlideRequest<Drawable> preloadRequest = null;
private MAdapter mAdapter;
private int PHOTO_SIZE = 180;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
fullRequest = GlideApp.with(this).asDrawable().centerCrop().override(PHOTO_SIZE);
preloadRequest = fullRequest;
rePreload();
}
private void rePreload() {
int spanCount = 5;
RecyclerView rv = findViewById(R.id.recycler_view);
GridLayoutManager layoutManager = new GridLayoutManager(this, spanCount);
rv.setLayoutManager(layoutManager);
mAdapter = new MAdapter(this);
rv.setAdapter(mAdapter);
int loadSize = 500;
FixedPreloadSizeProvider preloadSizeProvider = new FixedPreloadSizeProvider<MyData>(PHOTO_SIZE, PHOTO_SIZE);
MyPreloadModelProvider preloadModelProvider = new MyPreloadModelProvider();
RecyclerViewPreloader<MyData> preloader = new RecyclerViewPreloader(
GlideApp.with(this),
preloadModelProvider,
preloadSizeProvider,
loadSize
);
rv.addOnScrollListener(preloader);
new Thread(new Runnable() {
@Override
public void run() {
ArrayList<MyData> items = readAllImage(getApplicationContext());
runOnUiThread(new Runnable() {
@Override
public void run() {
mAdapter.onChange(items);
}
});
}
}).start();
}
private class MyPreloadModelProvider implements ListPreloader.PreloadModelProvider<MyData> {
@NonNull
@Override
public List<MyData> getPreloadItems(int position) {
List<MyData> list = new ArrayList<>();
list.add(mAdapter.items.get(position));
return list;
}
@Nullable
@Override
public RequestBuilder<?> getPreloadRequestBuilder(@NonNull MyData item) {
return preloadRequest.load(new File(item.path));
}
}
private class MAdapter extends RecyclerView.Adapter<MyVH> {
private Context context;
private ArrayList<MyData> items = new ArrayList<>();
public MAdapter(Context context) {
this.context = context;
}
public void onChange(ArrayList<MyData> items) {
this.items = items;
notifyDataSetChanged();
}
@NonNull
@Override
public MyVH onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
View view = LayoutInflater.from(context).inflate(R.layout.item, parent, false);
ViewGroup.LayoutParams params = view.getLayoutParams();
params.width = PHOTO_SIZE;
params.height = PHOTO_SIZE;
return new MyVH(view);
}
@Override
public void onBindViewHolder(@NonNull MyVH holder, int position) {
fullRequest.load(new File(items.get(position).path)).centerCrop().into(holder.image);
holder.text.setText(position + "");
}
@Override
public int getItemCount() {
return items.size();
}
}
private class MyVH extends RecyclerView.ViewHolder {
public AppCompatImageView image;
public TextView text;
public MyVH(@NonNull View itemView) {
super(itemView);
image = itemView.findViewById(R.id.image);
text = itemView.findViewById(R.id.text);
}
}
private ArrayList<MyData> readAllImage(Context context) {
ArrayList<MyData> photos = new ArrayList<>();
//读取手机图片
Cursor cursor = context.getContentResolver().query(
MediaStore.Images.Media.EXTERNAL_CONTENT_URI,
null,
null,
null,
null
);
int index = 0;
while (cursor.moveToNext()) {
//图片路径 uri
String path = cursor.getString(cursor.getColumnIndexOrThrow(MediaStore.Images.Media.DATA));
//图片名称
//val name = cursor.getString(cursor.getColumnIndexOrThrow(MediaStore.Images.Media.DISPLAY_NAME))
//图片大小
//val size = cursor.getLong(cursor.getColumnIndexOrThrow(MediaStore.Images.Media.SIZE))
photos.add(new MyData(path, index++));
}
cursor.close();
return photos;
}
private class MyData {
public String path;
public int index;
public MyData(String p, int i) {
path = p;
index = i;
}
}
}
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:padding="1dp">
<androidx.appcompat.widget.AppCompatImageView
android:id="@+id/image"
android:layout_width="80dp"
android:layout_height="wrap_content"
android:scaleType="centerCrop"
android:src="@drawable/ic_launcher_background" />
<TextView
android:id="@+id/text"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_centerInParent="true"
android:text="-.-"
android:textColor="@android:color/holo_red_dark"
android:textSize="20dp" />
</RelativeLayout>
import android.content.Context;
import android.util.Log;
import androidx.annotation.NonNull;
import com.bumptech.glide.GlideBuilder;
import com.bumptech.glide.annotation.GlideModule;
import com.bumptech.glide.load.engine.cache.LruResourceCache;
import com.bumptech.glide.module.AppGlideModule;
@GlideModule
public class MyModule extends AppGlideModule {
private LruResourceCache mCache = new LruResourceCache(1024 * 1024 * 800);
@Override
public void applyOptions(@NonNull Context context, @NonNull GlideBuilder builder) {
builder.setMemoryCache(mCache);
builder.setLogLevel(Log.DEBUG);
}
@Override
public boolean isManifestParsingEnabled() {
return false;
}
}
Android GlideApp GlideRequest FixedPreloadSizeProvider RecyclerViewPreloader, kotlin_zhangphil's blog-CSDN blog [Code] Android Paging 3, kotlin (1) In actual development, although Glide solves the problem of fast loading pictures, there is still one unresolved problem: such as the user's avatar , often the user's avatar is an ordinary rectangular picture read from the server, but the current design generally requires the user's avatar to be displayed as a circular avatar on the APP side, so although Glide can load it at this time, the loaded one is a rectangle. If you want Glide_android frosted glass rounded corners. "Android Image Loading and Caching Open Source Framework: Android Glide" Android Glide is an open source third-party framework for image loading and caching processing. 
https://blog.csdn.net/zhangphil/article/details/131813200