Android LoaderManager AsyncTaskLoader加载全部图片RecyclerView BigImageView呈现，Java（1）

太过爱你忘了你带给我的痛 2023-09-25 17:18 45阅读 0赞

## Android LoaderManager AsyncTaskLoader加载全部图片RecyclerView BigImageView呈现，Java（1） ##

权限：

<uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" />
        <uses-permission android:name="android.permission.READ_MEDIA_IMAGES" />

引用：

implementation 'com.github.piasy:BigImageViewer:1.8.1'
        implementation 'com.github.piasy:GlideImageLoader:1.8.1'

import androidx.annotation.NonNull;
    import androidx.annotation.Nullable;
    import androidx.appcompat.app.AppCompatActivity;
    import androidx.loader.app.LoaderManager;
    import androidx.loader.content.AsyncTaskLoader;
    import androidx.loader.content.Loader;
    import androidx.recyclerview.widget.LinearLayoutManager;
    import androidx.recyclerview.widget.RecyclerView;
    
    import android.content.Context;
    import android.database.Cursor;
    import android.os.Bundle;
    import android.provider.MediaStore;
    import android.util.Log;
    
    import java.io.File;
    import java.text.SimpleDateFormat;
    import java.util.ArrayList;
    import java.util.Date;
    import java.util.List;
    
    public class MainActivity extends AppCompatActivity {
        private static String TAG = "fly";
    
        private LoaderManager loaderManager;
    
        private PhotoAdapter photoAdapter;
    
        @Override
        protected void onCreate(Bundle savedInstanceState) {
            super.onCreate(savedInstanceState);
            setContentView(R.layout.activity_main);
            RecyclerView recyclerView = findViewById(R.id.recyclerview);
            LinearLayoutManager linearLayoutManager = new LinearLayoutManager(this);
            recyclerView.setLayoutManager(linearLayoutManager);
            photoAdapter= new PhotoAdapter(this);
            recyclerView.setAdapter(photoAdapter);
    
            setupLoader();
        }
    
        private static List<Photo> readImage(Context context) {
            List<Photo> photos = new ArrayList<>();
    
            //读取手机图片
            Cursor cursor = context.getContentResolver().query(MediaStore.Images.Media.EXTERNAL_CONTENT_URI, null, null, null, null);
            while (cursor.moveToNext()) {
                //图片的路径
                String path = cursor.getString(cursor.getColumnIndexOrThrow(MediaStore.Images.Media.DATA));
    
                //图片名称
                String name = cursor.getString(cursor.getColumnIndexOrThrow(MediaStore.Images.Media.DISPLAY_NAME));
    
                //图片最后修改日期
                //String date_modified = cursor.getString(cursor.getColumnIndexOrThrow(MediaStore.Images.Media.DATE_MODIFIED));
                File file = new File(path);
                SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd hh:mm:ss");
                String date = sdf.format(new Date(file.lastModified()));
    
                //图片大小
                long size = cursor.getLong(cursor.getColumnIndexOrThrow(MediaStore.Images.Media.SIZE));
                Photo photo = new Photo(name, date, size, path);
    
                photos.add(photo);
            }
    
            return photos;
        }
    
        private void setupLoader() {
            loaderManager = LoaderManager.getInstance(this);
            loaderManager.initLoader(2023, new Bundle(), loaderCallbacks);
        }
    
        private LoaderManager.LoaderCallbacks loaderCallbacks = new LoaderManager.LoaderCallbacks<List<Photo>>() {
            @NonNull
            @Override
            public MyLoader onCreateLoader(int id, @Nullable Bundle args) {
                Log.d(TAG, "onCreateLoader- id - " + id);
                MyLoader loader = new MyLoader(getApplicationContext());
                return loader;
            }
    
            @Override
            public void onLoadFinished(@NonNull Loader<List<Photo>> loader, List<Photo> photos) {
                Log.d(TAG, "onLoadFinished- " + loader.getId() + " - " + photos.size());
    
                photoAdapter.dataChanged(photos);
            }
    
            @Override
            public void onLoaderReset(@NonNull Loader loader) {
    
            }
        };
    
        @Override
        protected void onStart() {
            super.onStart();
            Log.d(TAG, "---");
            Log.d(TAG, "onStart");
        }
    
        @Override
        protected void onResume() {
            super.onResume();
            Log.d(TAG, "onResume");
        }
    
        @Override
        protected void onStop() {
            super.onStop();
            Log.d(TAG, "onStop");
        }
    
        private static class MyLoader extends AsyncTaskLoader<List<Photo>> {
            private Context context;
    
            public MyLoader(@NonNull Context context) {
                super(context);
                this.context = context;
            }
    
            @Override
            protected void onStartLoading() {
                super.onStartLoading();
                Log.d(TAG, "onStartLoading- " + getId());
    
                this.forceLoad();
            }
    
            //work thread
            @Nullable
            @Override
            public List<Photo> loadInBackground() {
                return readImage(context);
            }
    
            //UI main thread
            @Override
            public void deliverResult(@Nullable List<Photo> photos) {
                super.deliverResult(photos);
                Log.d(TAG, "deliverResult- " + getId() + " 图片总量:" + photos.size());
            }
    
            @Override
            public void onContentChanged() {
                super.onContentChanged();
                Log.d(TAG, "onContentChanged- " + getId());
            }
        }
    }

R.layout.activity\_main.xml

<?xml version="1.0" encoding="utf-8"?>
    <androidx.recyclerview.widget.RecyclerView xmlns:android="http://schemas.android.com/apk/res/android"
        xmlns:tools="http://schemas.android.com/tools"
        android:id="@+id/recyclerview"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        tools:context=".MainActivity">
    
    </androidx.recyclerview.widget.RecyclerView>

import android.content.ContentValues;
    import android.content.Context;
    import android.database.Cursor;
    import android.net.Uri;
    import android.provider.MediaStore;
    import android.view.LayoutInflater;
    import android.view.View;
    import android.view.ViewGroup;
    import android.widget.TextView;
    
    import androidx.recyclerview.widget.RecyclerView;
    
    import com.github.piasy.biv.BigImageViewer;
    import com.github.piasy.biv.loader.glide.GlideImageLoader;
    import com.github.piasy.biv.view.BigImageView;
    
    import java.util.ArrayList;
    import java.util.List;
    
    public class PhotoAdapter extends RecyclerView.Adapter<PhotoAdapter.PhotoViewHolder> {
        private Context context;
    
        private List<Photo> photos = new ArrayList<>();
    
        public PhotoAdapter(Context context) {
            this.context = context;
            BigImageViewer.initialize(GlideImageLoader.with(context));
        }
    
        public void dataChanged(List<Photo> photos) {
            this.photos = photos;
    
            notifyDataSetChanged();
        }
    
    
        @Override
        public PhotoViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
            View view = LayoutInflater.from(parent.getContext()).inflate(R.layout.image_item, parent, false);
            PhotoViewHolder holder = new PhotoViewHolder(view);
            return holder;
        }
    
        @Override
        public void onBindViewHolder(PhotoViewHolder holder, int pos) {
            holder.textView.setText(photos.get(pos).name);
            holder.imageView.showImage(getImageUri(context, photos.get(pos).path));
            //Glide.with(context).load(new File(photos.get(pos).path)).into(holder.imageView);
        }
    
        @Override
        public int getItemCount() {
            return photos.size();
        }
    
        public class PhotoViewHolder extends RecyclerView.ViewHolder {
            public BigImageView imageView;
    
            public TextView textView;
    
            public PhotoViewHolder(View itemView) {
                super(itemView);
    
                imageView = itemView.findViewById(R.id.image);
                textView = itemView.findViewById(R.id.text);
            }
        }
    
        public static Uri getImageUri(Context context, String filePath) {
            Cursor cursor = context.getContentResolver().query(MediaStore.Images.Media.EXTERNAL_CONTENT_URI,
                    new String[]{MediaStore.Images.Media._ID}, MediaStore.Images.Media.DATA + "=? ",
                    new String[]{filePath}, null);
            if (cursor != null && cursor.moveToFirst()) {
                int id = cursor.getInt(cursor.getColumnIndexOrThrow(MediaStore.MediaColumns._ID));
                Uri baseUri = Uri.parse("content://media/external/images/media");
                return Uri.withAppendedPath(baseUri, "" + id);
            } else {
                ContentValues values = new ContentValues();
                values.put(MediaStore.Images.Media.DATA, filePath);
                return context.getContentResolver().insert(MediaStore.Images.Media.EXTERNAL_CONTENT_URI, values);
            }
        }
    }

image\_item.xml

<?xml version="1.0" encoding="utf-8"?>
    <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:orientation="vertical">
    
        <com.github.piasy.biv.view.BigImageView
            android:id="@+id/image"
            android:layout_width="match_parent"
            android:layout_height="wrap_content" />
    
        <TextView
            android:id="@+id/text"
            android:layout_width="match_parent"
            android:layout_height="wrap_content" />
    
        <View
            android:layout_width="match_parent"
            android:layout_height="1px"
            android:background="@android:color/darker_gray" />
    
    </LinearLayout>

public class Photo {
        public String name;//名称
        public String date;//日期
        public long size;  //大小
        public String path;//路径
    
        public Photo(String name, String date, long size, String path) {
            this.name = name;
            this.date = date;
            this.size = size;
            this.path = path;
        }
    }

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[Android LoaderManager CursorLoader_RecyclerView BigImageView_Java_2_zhangphil_-CSDN_Android_QQ_APP_1_Android_android _zhangphil_-CSDN_Android_zhangphil_-CSDN_favicon32.ico_https_blog.csdn.net_zhangphil_article_details_129641492]: https://blog.csdn.net/zhangphil/article/details/129641492