仿淘宝商品详情页顶部banner和沉浸式效果

这边使用第三方沉浸式库https://github.com/gyf-dev/ImmersionBar 使用自己去研究

一、沉浸式效果

主要是看滑动过程中toolBar的透明度变化

布局如下：

<android.support.design.widget.CoordinatorLayout
    android:id="@+id/coordinator"
    android:layout_width="match_parent"
    android:layout_height="match_parent">

    <android.support.design.widget.AppBarLayout
        android:id="@+id/appbar"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:theme="@style/AppTheme.AppBarOverlay">

        <android.support.design.widget.CollapsingToolbarLayout
            android:id="@+id/collapsing_toolbar"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            app:contentScrim="?attr/colorPrimary"
            app:expandedTitleMarginEnd="@dimen/size_titlebar"
            app:expandedTitleMarginStart="20dp"
            app:layout_scrollFlags="scroll|exitUntilCollapsed">               
     
            <android.support.v7.widget.Toolbar
                android:id="@+id/toolBar"
                android:layout_width="match_parent"
                android:layout_height="@dimen/size_titlebar"
                app:contentInsetStart="0dp"
                app:layout_collapseMode="pin">

            </android.support.v7.widget.Toolbar>
        </android.support.design.widget.CollapsingToolbarLayout>

    </android.support.design.widget.AppBarLayout>

</android.support.design.widget.CoordinatorLayout>

设置状态栏为透明：

getmImmersionBar()
        .titleBar(binding.toolBar, false)//解决状态栏和布局重叠问题
        .transparentBar()
        .init();

重点是监听appbar的滑动：

binding.appbar.addOnOffsetChangedListener(new AppBarLayout.OnOffsetChangedListener() {
    @Override
    public void onOffsetChanged(AppBarLayout appBarLayout, int i) {
        int scroll = Math.abs(i);
        int max = binding.banner.getHeight() - binding.toolBar.getHeight();//设置滑动最大高度，超出后toolBar都设置不透明
        if (scroll < max) {
            float alpha = (float) scroll / max;
            if (alpha > 0.5f) {
                ImmersionBar.with(CourdeDetailSlideActivity.this)
                        .statusBarDarkFont(true)//状态栏字体黑色
                        .addViewSupportTransformColor(binding.toolBar, R.color.white)//设置支持view变色
                        .barAlpha(alpha)
                        .init();
                binding.icBack.setImageResource(R.mipmap.icon_back_black);//返回按钮改成黑色【我这边背景色是白色，如果不是白色可不改变颜色】
                binding.barTitle.setTextColor(getResources().getColor(R.color.text_3));//标题字体改成黑色
            } else {
                ImmersionBar.with(CourdeDetailSlideActivity.this)
                        .statusBarDarkFont(false)//状态栏字体白色
                        .addViewSupportTransformColor(binding.toolBar, R.color.white)
                        .barAlpha(alpha)
                        .init();
                binding.icBack.setImageResource(R.mipmap.nav_back_white);
                binding.barTitle.setTextColor(getResources().getColor(R.color.white));
            }
        } else {
            GSYVideoManager.onPause();//滑动超出banner显示区域，视频播放暂停
            ImmersionBar.with(CourdeDetailSlideActivity.this)
                    .statusBarDarkFont(true)
                    .addViewSupportTransformColor(binding.toolBar, R.color.white)
                    .barAlpha(1.0f)
                    .init();
            binding.icBack.setImageResource(R.mipmap.icon_back_black);
            binding.barTitle.setTextColor(getResources().getColor(R.color.text_3));
        }
    }
});

二、banner效果

这边我使用RecyclerView来实现多布局效果

MultiTypeSupport multiTypeSupport = new MultiTypeSupport() {
    @Override
    public int getLayoutId(Object item, int position) {
        if (mTopLists.get(position).getShowType() == 1) {//根据显示类型判断是视频还是图片
            return R.layout.course_detail_top_video;
        } else {
            return R.layout.course_detail_top_image;
        }
    }
};
if (mTopAdapter == null) {
    mTopAdapter = new CommonRecyclerAdapter<CourseTopVideoImage>(this, mTopLists, multiTypeSupport) {
        @Override
        public void convert(ViewHolder holder, CourseTopVideoImage item, int position) {
            if (item.getShowType() == 1) {//视频
                StandardGSYVideoPlayer gsyVideoPlayer = holder.getView(R.id.video_item_player);
                //增加封面
                ImageView imageView = new ImageView(App.getContext());
                imageView.setScaleType(ImageView.ScaleType.CENTER_CROP);
                ImageUtils.newInstance().load(item.getImagePath(), imageView);
                if (imageView.getParent() != null) {
                    ViewGroup viewGroup = (ViewGroup) imageView.getParent();
                    viewGroup.removeView(imageView);
                }
                GSYVideoOptionBuilder gsyVideoOptionBuilder = new GSYVideoOptionBuilder();
                gsyVideoOptionBuilder
                        .setIsTouchWiget(false)
                        .setThumbImageView(imageView)
                        .setUrl(item.getPath())
                        .setVideoTitle("")
                        .setCacheWithPlay(false)
                        .setRotateViewAuto(true)
                        .setLockLand(true)
                        .setPlayTag("")
                        .setNeedShowWifiTip(false)
                        .setShowFullAnimation(true)
                        .setNeedLockFull(true)
                        .setPlayPosition(position)
                        .setVideoAllCallBack(new GSYSampleCallBack() {
                            @Override
                            public void onPrepared(String url, Object... objects) {
                                super.onPrepared(url, objects);
                                if (!gsyVideoPlayer.isIfCurrentIsFullscreen()) {
                                    //静音
                                    // GSYVideoManager.instance().setNeedMute(true);
                                }
                            }

                            @Override
                            public void onQuitFullscreen(String url, Object... objects) {
                                super.onQuitFullscreen(url, objects);
                                //全屏不静音
                                // GSYVideoManager.instance().setNeedMute(true);
                            }

                            @Override
                            public void onEnterFullscreen(String url, Object... objects) {
                                super.onEnterFullscreen(url, objects);
                                // GSYVideoManager.instance().setNeedMute(false);
                            }
                        }).build(gsyVideoPlayer);
                //增加title
                gsyVideoPlayer.getTitleTextView().setVisibility(View.GONE);
                //设置返回键
                gsyVideoPlayer.getBackButton().setVisibility(View.GONE);
                //设置全屏按键功能
                gsyVideoPlayer.getFullscreenButton().setVisibility(View.GONE);
            } else {//图片
                ImageView imageView = holder.getView(R.id.imageView);
                ImageUtils.newInstance().load(item.getImagePath(), imageView);
            }
        }
    };
}
LinearLayoutManager linearLayoutManager = new LinearLayoutManager(this);
linearLayoutManager.setOrientation(LinearLayoutManager.HORIZONTAL);//设置滑动方向为横向滑动
PagerSnapHelper snapHelper = new PagerSnapHelper();//设置一次只能滑动一页，不能快速滑动
binding.banner.setOnFlingListener(null);
snapHelper.attachToRecyclerView(binding.banner);
binding.banner.setLayoutManager(linearLayoutManager);
binding.banner.setAdapter(mTopAdapter);

binding.banner.addOnScrollListener(new RecyclerView.OnScrollListener() {
    int firstVisibleItem, lastVisibleItem;

    @Override
    public void onScrollStateChanged(@NonNull RecyclerView recyclerView, int newState) {
        super.onScrollStateChanged(recyclerView, newState);
    }

    @Override
    public void onScrolled(@NonNull RecyclerView recyclerView, int dx, int dy) {
        super.onScrolled(recyclerView, dx, dy);
        firstVisibleItem = linearLayoutManager.findFirstVisibleItemPosition();
        lastVisibleItem = linearLayoutManager.findLastVisibleItemPosition();
        //大于0说明有播放
        if (GSYVideoManager.instance().getPlayPosition() >= 0) {
            //当前播放的位置
            int position = GSYVideoManager.instance().getPlayPosition();
            //对应的播放列表TAG
            if (position < firstVisibleItem || position > lastVisibleItem) {
                GSYVideoManager.onPause();//切换停止播放
            }
        }
    }
});