安卓九宫格布局（图片上传、预览）

前言：
利用RecyclerView展示朋友圈UI布局，包含展示、预览、删除等功能

效果图

1、在项目app\build.gradle添加依赖

    //图片加载
    implementation 'com.github.bumptech.glide:glide:4.8.0'
    //初始化控件找ID
    implementation 'com.jakewharton:butterknife:10.2.1'
    annotationProcessor 'com.jakewharton:butterknife-compiler:10.2.1'
    //图片选择器
    implementation 'com.github.LuckSiege.PictureSelector:picture_library:v2.5.8'
    //权限请求
    implementation 'com.hjq:xxpermissions:6.5'

build.gradle主项目中添加：maven { url ‘https://jitpack.io’ }

allprojects {
    repositories {
        google()
        jcenter()
        maven { url 'https://jitpack.io' }
    }
}

具体使用：
①、MainActivity：

public class MainActivity extends AppCompatActivity {

    private static final String TAG = "MainActivity";
    @BindView(R.id.edit)
    EditText edit;
    @BindView(R.id.recycler)
    RecyclerView recycler;
    private SelectPlotAdapter adapter;
    private ArrayList<String> allSelectList;//所有的图片集合
    private ArrayList<String> categoryLists;//查看图片集合
    private List<LocalMedia> selectList = new ArrayList<>();

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        ButterKnife.bind(this);
        if (null == allSelectList) {
            allSelectList = new ArrayList();
        }
        if (null == categoryLists) {
            categoryLists = new ArrayList();
        }
        Tools.requestPermissions(MainActivity.this);
        initAdapter();
    }

    private void initAdapter() {
        //最多9张图片
        adapter = new SelectPlotAdapter(this, 9);
        recycler.setLayoutManager(new GridLayoutManager(this, 3));
        adapter.setImageList(allSelectList);
        recycler.setAdapter(adapter);
        adapter.setListener(new SelectPlotAdapter.CallbackListener() {
            @Override
            public void add() {
                //可添加的最大张数=9-当前已选的张数
                int size = 9 - allSelectList.size();
                Tools.galleryPictures(MainActivity.this, size);
            }

            @Override
            public void delete(int position) {
                allSelectList.remove(position);
                categoryLists.remove(position);
                adapter.setImageList(allSelectList);//再set所有集合
            }

            @Override
            public void item(int position, List<String> mList) {
                selectList.clear();
                for (int i = 0; i < allSelectList.size(); i++) {
                    LocalMedia localMedia = new LocalMedia();
                    localMedia.setPath(allSelectList.get(i));
                    selectList.add(localMedia);
                }
                //①、图片选择器自带预览
                PictureSelector.create(MainActivity.this)
                        .themeStyle(R.style.picture_default_style)
                        .isNotPreviewDownload(true)//是否显示保存弹框
                        .imageEngine(GlideEngine.createGlideEngine()) // 选择器展示不出图片则添加
                        .openExternalPreview(position, selectList);
                //②:自定义布局预览
                //Tools.startPhotoViewActivity(MainActivity.this, categoryLists, position);
            }
        });
    }


    @Override
    protected void onActivityResult(int requestCode, int resultCode, @Nullable Intent data) {
        super.onActivityResult(requestCode, resultCode, data);
        if (resultCode == RESULT_OK) {
            // 结果回调
            List<LocalMedia> selectList = PictureSelector.obtainMultipleResult(data);
            showSelectPic(selectList);
        }
    }

    private void showSelectPic(List<LocalMedia> result) {
        for (int i = 0; i < result.size(); i++) {
            String path;
            //判断是否10.0以上
            if (Build.VERSION.SDK_INT >= 29) {
                path = result.get(i).getAndroidQToPath();
            } else {
                path = result.get(i).getPath();
            }
            allSelectList.add(path);
            categoryLists.add(path);
            Log.e(TAG, "图片链接: " + path);
        }
        adapter.setImageList(allSelectList);
    }

    @OnClick({R.id.upload})
    public void onClick(View view) {
        switch (view.getId()) {
            case R.id.upload:
                String content = edit.getText().toString();
                if (TextUtils.isEmpty(content)) {
                    Toast.makeText(this, "请输入上传内容", Toast.LENGTH_LONG).show();
                    return;
                }
                if (allSelectList.size() == 0) {
                    Toast.makeText(this, "请选择图片进行上传", Toast.LENGTH_LONG).show();
                    return;
                }
                Log.e(TAG, "内容: " + content);
                Log.e(TAG, "图片: " + allSelectList.toString());
                break;
        }
    }
}

②、SelectPlotAdapter 展示适配器

public class SelectPlotAdapter extends RecyclerView.Adapter<SelectPlotAdapter.SelectHolder> {

    private Context mContext;
    private List<String> mediaDtoList;
    //最大图片张数
    private int picMax;

    public void setImageList(List<String> mList) {
        this.mediaDtoList = mList;
        notifyDataSetChanged();
    }

    public SelectPlotAdapter(Context mContext, int max) {
        this.mContext = mContext;
        this.picMax = max;
    }

    @Override
    public SelectHolder onCreateViewHolder(ViewGroup parent, int viewType) {
        return new SelectHolder(LayoutInflater.from(mContext).
                inflate(R.layout.item_gallery, parent, false));
    }

    @Override
    public void onBindViewHolder(SelectHolder holder, final int position) {
        //当前位置大于图片数量并且小于最大减1
        if (position >= mediaDtoList.size() && position <= (picMax - 1)) {
            //显示添加图片按钮、并隐藏删除按钮
            Tools.showGlide(mContext,holder.gallery,"");
            holder.delete.setVisibility(View.GONE);
        } else {
            //显示本地或网络图片，并显示删除按钮
            Tools.showGlide(mContext,holder.gallery,mediaDtoList.get(position));
            holder.delete.setVisibility(View.VISIBLE);
        }
        //按钮删除事件
        holder.delete.setOnClickListener(v -> {
            //传入position删除第几张
            listener.delete(position);
        });
        holder.gallery.setOnClickListener(v -> {
            //添加新图片点击事件（回调activity）
            if (position >= mediaDtoList.size() && position <= (picMax - 1)) {
                listener.add();
            } else {
                //点击查看图片事件，并将最新list传入actiuvity
                listener.item(position, mediaDtoList);
            }
        });
    }

    @Override
    public int getItemCount() {
        if (mediaDtoList == null || mediaDtoList.size() == 0) {
            return 1;
        } else {
            return this.mediaDtoList.size() >= picMax ? picMax : this.mediaDtoList.size() + 1;
        }
    }

    public class SelectHolder extends RecyclerView.ViewHolder {

        private ImageView gallery;
        private ImageView delete;

        public SelectHolder(View itemView) {
            super(itemView);
            gallery = itemView.findViewById(R.id.im_show_gallery);
            delete = itemView.findViewById(R.id.iv_del);
        }
    }

    private CallbackListener listener;

    public void setListener(CallbackListener listener) {
        this.listener = listener;
    }

    public interface CallbackListener {

        //图片添加事件
        void add();

        //删除第几张图片
        void delete(int position);

        //图片点击
        void item(int position, List<String> mList);
    }
}

由于Butterknife需使用Java 8故需在依赖处添加

  // Butterknife requires Java 8.
    compileOptions {
        sourceCompatibility JavaVersion.VERSION_1_8
        targetCompatibility JavaVersion.VERSION_1_8
    }

③、自定义图片预览MyImageAdapter（需要则添加）

public class MyImageAdapter extends PagerAdapter {

    private List<String> imageUrls;
    private Activity mContext;

    public MyImageAdapter(Activity context, List<String> imageUrls) {
        this.imageUrls = imageUrls;
        this.mContext = context;
    }

    @Override
    public Object instantiateItem(ViewGroup container, int position) {
        String url = imageUrls.get(position);
        PhotoView photoView = new PhotoView(mContext);
        Tools.showGlide(mContext, photoView, url);
        container.addView(photoView);
        photoView.setOnClickListener(v -> mContext.finish());
        return photoView;
    }

    @Override
    public int getCount() {
        return imageUrls != null ? imageUrls.size() : 0;
    }

    @Override
    public boolean isViewFromObject(View view, Object object) {
        return view == object;
    }

    @Override
    public void destroyItem(ViewGroup container, int position, Object object) {
        container.removeView((View) object);
    }

    @Override
    public int getItemPosition(Object object) {
        return POSITION_NONE;
    }
}

④、工具类Tools：

public class Tools {

    /**
     * 请求权限
     */
    public static void requestPermissions(final AppCompatActivity activity) {
        XXPermissions.with(activity)
                // 可设置被拒绝后继续申请，直到用户授权或者永久拒绝
                //.constantRequest()
                // 支持请求6.0悬浮窗权限8.0请求安装权限
                //.permission(Permission.SYSTEM_ALERT_WINDOW, Permission.REQUEST_INSTALL_PACKAGES)
                // 不指定权限则自动获取清单中的危险权限
                .permission(Permission.Group.STORAGE)
                .permission(Permission.CAMERA)
                .request(new OnPermission() {
                    @Override
                    public void hasPermission(List<String> granted, boolean all) {
                    }

                    @Override
                    public void noPermission(List<String> denied, boolean quick) {
                    }
                });
    }

    /**
     * 打开图库
     */
    public static void openGallery(AppCompatActivity activity, int maxSize) {
        PictureSelector.create(activity)
                .openGallery(PictureMimeType.ofImage())//全部.PictureMimeType.ofAll()、图片.ofImage()、视频.ofVideo()、音频.ofAudio()
                //.theme()//主题样式(不设置为默认样式) 也可参考demo values/styles下 例如：R.style.picture.white.style
                .maxSelectNum(maxSize)// 最大图片选择数量 int
                .minSelectNum(1)// 最小选择数量 int
                .imageSpanCount(3)// 每行显示个数 int
                .imageEngine(GlideEngine.createGlideEngine())
                //.selectionMode()// 多选 or 单选 PictureConfig.MULTIPLE or PictureConfig.SINGLE
                //.isPreviewImage(true)// 是否可预览图片 true or false
                //.isPreviewVideo()// 是否可预览视频 true or false
                //.freeStyleCropEnabled() // 是否可播放音频 true or false
                .isCamera(false)// 是否显示拍照按钮 true or false
                //.imageFormat(PictureMimeType.PNG)// 拍照保存图片格式后缀,默认jpeg
                .isZoomAnim(true)// 图片列表点击 缩放效果 默认true
                //.setOutputCameraPath("/CustomPath")// 自定义拍照保存路径,可不填
                .isEnableCrop(true)// 是否裁剪 true or false
                //.isCompress(true)// 是否压缩 true or false
                //.withAspectRatio()// int 裁剪比例 如16:9 3:2 3:4 1:1 可自定义
                //.hideBottomControls()// 是否显示uCrop工具栏，默认不显示 true or false
                //.isGif(false)// 是否显示gif图片 true or false
                //.compressSavePath(getPath())//压缩图片保存地址
                .freeStyleCropEnabled(true)// 裁剪框是否可拖拽 true or false
                //.circleDimmedLayer()// 是否圆形裁剪 true or false
                //.showCropFrame()// 是否显示裁剪矩形边框 圆形裁剪时建议设为false   true or false
                //.showCropGrid()// 是否显示裁剪矩形网格 圆形裁剪时建议设为false    true or false
                //.isOpenClickSound(false)// 是否开启点击声音 true or false
                //.selectionData()// 是否传入已选图片 List<LocalMedia> list
                //.isPreviewEggs()// 预览图片时 是否增强左右滑动图片体验(图片滑动一半即可看到上一张是否选中) true or false
                //.cutOutQuality(90)// 裁剪压缩质量 默认90 int
                .minimumCompressSize(100)// 小于100kb的图片不压缩
                //.synOrAsy(true)//同步true或异步false 压缩 默认同步
                //.cropImageWideHigh()// 裁剪宽高比，设置如果大于图片本身宽高则无效 int
                //.rotateEnabled(true) // 裁剪是否可旋转图片 true or false
                .scaleEnabled(true)// 裁剪是否可放大缩小图片 true or false
                //.videoQuality()// 视频录制质量 0 or 1 int
                //.videoMaxSecond(15)// 显示多少秒以内的视频or音频也可适用 int
                //.videoMinSecond(10)// 显示多少秒以内的视频or音频也可适用 int
                //.recordVideoSecond()//视频秒数录制 默认60s int
                .forResult(PictureConfig.CHOOSE_REQUEST);//结果回调onActivityResult code
    }

    /**
     * 打开拍照
     */
    public static void takingPictures(AppCompatActivity activity) {
        PictureSelector.create(activity)
                .openCamera(PictureMimeType.ofImage())
                .forResult(PictureConfig.REQUEST_CAMERA);
    }

    /**
     * 打开图库+拍照按钮
     */
    public static void galleryPictures(AppCompatActivity activity, int maxSize) {
        PictureSelector.create(activity)
                .openGallery(PictureMimeType.ofImage())//全部.PictureMimeType.ofAll()、图片.ofImage()、视频.ofVideo()、音频.ofAudio()
                //.theme()//主题样式(不设置为默认样式) 也可参考demo values/styles下 例如：R.style.picture.white.style
                .maxSelectNum(maxSize)// 最大图片选择数量 int
                .minSelectNum(1)// 最小选择数量 int
                .imageEngine(GlideEngine.createGlideEngine())
                .imageSpanCount(3)// 每行显示个数 int
                .isCamera(true)// 是否显示拍照按钮 true or false
                .isZoomAnim(true)// 图片列表点击 缩放效果 默认true
                //.isEnableCrop(true)// 是否裁剪 true or false
                .isCompress(true)// 是否压缩 true or false
                .minimumCompressSize(100)// 小于100kb的图片不压缩
                .forResult(PictureConfig.CHOOSE_REQUEST);//结果回调onActivityResult code
    }

    /**
     * 加载圆角图片
     *
     * @param context 上下文
     * @param view    图片控件
     * @param url     网络图片地址
     */

    public static void showGlide(Context context, ImageView view, String url) {
        RequestOptions options = new RequestOptions()
                .error(R.mipmap.ic_add)
                .transform(new GlideRoundTransform(context,5));
        Glide.with(context)
                .load(url)
                .apply(options)
                .into(view);
    }

    /**
     * 跳转到查看图片界面
     * 上下文、list、点击的位置
     */
    public static void startPhotoViewActivity(Activity context, ArrayList<String> mList, int position) {
        Intent intent = new Intent(context, PhotoViewActivity.class);
        Bundle bundle = new Bundle();
        bundle.putStringArrayList("list", mList);
        intent.putExtras(bundle);
        intent.putExtra("position", position);
        context.startActivity(intent);
    }
}

⑤、自定义PhotoViewActivity（需要则添加）：

public class PhotoViewActivity extends AppCompatActivity {

    @BindView(R.id.viewpager)
    ViewPager viewpager;
    @BindView(R.id.mTvImageCount)
    TextView mTvImageCount;
    //点击的下标
    private int currentPosition;
    private List<String> urlLists;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_photo_view);
        ButterKnife.bind(this);
        initData();
    }

    private void initData() {
        if (null == urlLists) {
            urlLists = new ArrayList<>();
        }
        //获得点击的位置
        currentPosition = getIntent().getIntExtra("position", 0);
        //图片集合
        urlLists = getIntent().getStringArrayListExtra("list");
        MyImageAdapter adapter = new MyImageAdapter(this, urlLists);
        viewpager.setAdapter(adapter);
        viewpager.setCurrentItem(currentPosition);
        mTvImageCount.setText(currentPosition + 1 + "/" + urlLists.size());
        viewpager.addOnPageChangeListener(new ViewPager.OnPageChangeListener() {
            @Override
            public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) {
            }

            @Override
            public void onPageSelected(int position) {
                mTvImageCount.setText(position + 1 + "/" + urlLists.size());
            }

            @Override
            public void onPageScrollStateChanged(int state) {
            }
        });
    }
}

⑥：布局相关文件：
1、activity_main.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:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    tools:context=".MainActivity">


    <EditText
        android:id="@+id/edit"
        android:layout_width="match_parent"
        android:layout_height="200dp"
        android:gravity="top"
        android:hint="请输入上传内容"
        android:padding="15dp" />

    <androidx.recyclerview.widget.RecyclerView
        android:id="@+id/recycler"
        android:layout_width="match_parent"
        android:layout_height="0dp"
        android:layout_weight="1"
        android:layout_margin="15dp" />

    <Button
        android:id="@+id/upload"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_margin="20dp"
        android:text="提交" />
</LinearLayout>

2、item_gallery.xml

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="100dp"
    android:layout_height="100dp"
    android:layout_marginBottom="5dp"
    android:paddingRight="5dp">

    <ImageView
        android:id="@+id/im_show_gallery"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:scaleType="centerCrop" />

    <ImageView
        android:id="@+id/iv_del"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentEnd="true"
        android:paddingBottom="5dp"
        android:paddingStart="5dp"
        android:src="@drawable/picture_icon_delete_photo" />

</RelativeLayout>

picture_icon_delete_photo为自带删除按钮，如需更换自行修改

3、activity_photo_view.xml

<?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"
    android:background="#000000"
    tools:context=".PhotoViewActivity">

    <androidx.viewpager.widget.ViewPager
        android:layout_centerInParent="true"
        android:id="@+id/viewpager"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginTop="30dp"
        android:layout_marginBottom="30dp"/>

    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:textColor="#ffffff"
        android:textSize="16sp"
        android:id="@+id/mTvImageCount"
        android:layout_alignParentBottom="true"
        android:layout_centerHorizontal="true"
        android:layout_marginBottom="5dp"
        android:text="1/1" />

</RelativeLayout>

⑦、app\src\main\AndroidManifest.xml添加相应权限

<uses-permission android:name="android.permission.CAMERA" />
<uses-permission android:name="android.permission.INTERNET" />
<uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" />
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />

扩展相关
1、图片圆角GlideRoundTransform：

public class GlideRoundTransform extends BitmapTransformation {

    private static float radius = 0f;

    public GlideRoundTransform(Context context) {
        this(context, 4);
    }

    /**
     * 圆角大小
     * @param context
     * @param dp
     */
    public GlideRoundTransform(Context context, int dp) {
        //super(context);
        this.radius = Resources.getSystem().getDisplayMetrics().density * dp;
    }


    @Override
    protected Bitmap transform(BitmapPool pool, Bitmap toTransform, int outWidth, int outHeight) {
        Bitmap bitmap = TransformationUtils.centerCrop(pool, toTransform, outWidth, outHeight);
        return roundCrop(pool, bitmap);
    }

    private static Bitmap roundCrop(BitmapPool pool, Bitmap source) {
        if (source == null) return null;

        Bitmap result = pool.get(source.getWidth(), source.getHeight(), Bitmap.Config.ARGB_8888);
        if (result == null) {
            result = Bitmap.createBitmap(source.getWidth(), source.getHeight(), Bitmap.Config.ARGB_8888);
        }

        Canvas canvas = new Canvas(result);
        Paint paint = new Paint();
        paint.setShader(new BitmapShader(source, BitmapShader.TileMode.CLAMP, BitmapShader.TileMode.CLAMP));
        paint.setAntiAlias(true);
        RectF rectF = new RectF(0f, 0f, source.getWidth(), source.getHeight());
        canvas.drawRoundRect(rectF, radius, radius, paint);
        return result;
    }

    public String getId() {
        return getClass().getName() + Math.round(radius);
    }

    @Override
    public void updateDiskCacheKey(MessageDigest messageDigest) {

    }
}

2、图片选择器加载图片失败GlideEngine：

public class GlideEngine implements ImageEngine {

    /**
     * 加载图片
     *
     * @param context
     * @param url
     * @param imageView
     */
    @Override
    public void loadImage(@NonNull Context context, @NonNull String url, @NonNull ImageView imageView) {
        Glide.with(context)
                .load(url)
                .into(imageView);
    }

    /**
     * 加载网络图片适配长图方案
     * # 注意：此方法只有加载网络图片才会回调
     *
     * @param context
     * @param url
     * @param imageView
     * @param longImageView
     * @param callback      网络图片加载回调监听 {link after version 2.5.1 Please use the #OnImageCompleteCallback#}
     */
    @Override
    public void loadImage(@NonNull Context context, @NonNull String url,
                          @NonNull ImageView imageView,
                          SubsamplingScaleImageView longImageView, OnImageCompleteCallback callback) {
        Glide.with(context)
                .asBitmap()
                .load(url)
                .into(new ImageViewTarget<Bitmap>(imageView) {
                    @Override
                    public void onLoadStarted(@Nullable Drawable placeholder) {
                        super.onLoadStarted(placeholder);
                        if (callback != null) {
                            callback.onShowLoading();
                        }
                    }

                    @Override
                    public void onLoadFailed(@Nullable Drawable errorDrawable) {
                        super.onLoadFailed(errorDrawable);
                        if (callback != null) {
                            callback.onHideLoading();
                        }
                    }

                    @Override
                    protected void setResource(@Nullable Bitmap resource) {
                        if (callback != null) {
                            callback.onHideLoading();
                        }
                        if (resource != null) {
                            boolean eqLongImage = MediaUtils.isLongImg(resource.getWidth(),
                                    resource.getHeight());
                            longImageView.setVisibility(eqLongImage ? View.VISIBLE : View.GONE);
                            imageView.setVisibility(eqLongImage ? View.GONE : View.VISIBLE);
                            if (eqLongImage) {
                                // 加载长图
                                longImageView.setQuickScaleEnabled(true);
                                longImageView.setZoomEnabled(true);
                                longImageView.setPanEnabled(true);
                                longImageView.setDoubleTapZoomDuration(100);
                                longImageView.setMinimumScaleType(SubsamplingScaleImageView.SCALE_TYPE_CENTER_CROP);
                                longImageView.setDoubleTapZoomDpi(SubsamplingScaleImageView.ZOOM_FOCUS_CENTER);
                                longImageView.setImage(ImageSource.bitmap(resource),
                                        new ImageViewState(0, new PointF(0, 0), 0));
                            } else {
                                // 普通图片
                                imageView.setImageBitmap(resource);
                            }
                        }
                    }
                });
    }

    /**
     * 加载网络图片适配长图方案
     * # 注意：此方法只有加载网络图片才会回调
     *
     * @param context
     * @param url
     * @param imageView
     * @param longImageView
     * @ 已废弃
     */
    @Override
    public void loadImage(@NonNull Context context, @NonNull String url,
                          @NonNull ImageView imageView,
                          SubsamplingScaleImageView longImageView) {
        Glide.with(context)
                .asBitmap()
                .load(url)
                .into(new ImageViewTarget<Bitmap>(imageView) {
                    @Override
                    protected void setResource(@Nullable Bitmap resource) {
                        if (resource != null) {
                            boolean eqLongImage = MediaUtils.isLongImg(resource.getWidth(),
                                    resource.getHeight());
                            longImageView.setVisibility(eqLongImage ? View.VISIBLE : View.GONE);
                            imageView.setVisibility(eqLongImage ? View.GONE : View.VISIBLE);
                            if (eqLongImage) {
                                // 加载长图
                                longImageView.setQuickScaleEnabled(true);
                                longImageView.setZoomEnabled(true);
                                longImageView.setPanEnabled(true);
                                longImageView.setDoubleTapZoomDuration(100);
                                longImageView.setMinimumScaleType(SubsamplingScaleImageView.SCALE_TYPE_CENTER_CROP);
                                longImageView.setDoubleTapZoomDpi(SubsamplingScaleImageView.ZOOM_FOCUS_CENTER);
                                longImageView.setImage(ImageSource.bitmap(resource),
                                        new ImageViewState(0, new PointF(0, 0), 0));
                            } else {
                                // 普通图片
                                imageView.setImageBitmap(resource);
                            }
                        }
                    }
                });
    }

    /**
     * 加载相册目录
     *
     * @param context   上下文
     * @param url       图片路径
     * @param imageView 承载图片ImageView
     */
    @Override
    public void loadFolderImage(@NonNull Context context, @NonNull String url, @NonNull ImageView imageView) {
        Glide.with(context)
                .asBitmap()
                .load(url)
                .apply(new RequestOptions().placeholder(R.drawable.picture_image_placeholder))
                .into(new BitmapImageViewTarget(imageView) {
                    @Override
                    protected void setResource(Bitmap resource) {
                        RoundedBitmapDrawable circularBitmapDrawable =
                                RoundedBitmapDrawableFactory.
                                        create(context.getResources(), resource);
                        circularBitmapDrawable.setCornerRadius(8);
                        imageView.setImageDrawable(circularBitmapDrawable);
                    }
                });
    }

    /**
     * 加载gif
     *
     * @param context   上下文
     * @param url       图片路径
     * @param imageView 承载图片ImageView
     */
    @Override
    public void loadAsGifImage(@NonNull Context context, @NonNull String url,
                               @NonNull ImageView imageView) {
        Glide.with(context)
                .asGif()
                .load(url)
                .into(imageView);
    }

    /**
     * 加载图片列表图片
     *
     * @param context   上下文
     * @param url       图片路径
     * @param imageView 承载图片ImageView
     */
    @Override
    public void loadGridImage(@NonNull Context context, @NonNull String url, @NonNull ImageView imageView) {
        Glide.with(context)
                .load(url)
                .apply(new RequestOptions().placeholder(R.drawable.picture_image_placeholder))
                .into(imageView);
    }

    private GlideEngine() {
    }

    private static GlideEngine instance;

    public static GlideEngine createGlideEngine() {
        if (null == instance) {
            synchronized (GlideEngine.class) {
                if (null == instance) {
                    instance = new GlideEngine();
                }
            }
        }
        return instance;
    }
}

本文地址：https://blog.csdn.net/qq_34536167/article/details/107287072