RecyclerView 截屏

最新推荐文章于 2024-03-16 13:50:20 发布

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#RecycleView #截屏

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本文介绍了一种将整个RecyclerView截取为一张完整图片的方法。通过调用每个ItemView的setDrawingCacheEnabled(true)方法获取Bitmap，整合所有ItemView的Bitmap形成大图片。详细展示了如何避免内存溢出，以及如何正确测量、布局和绘制每个Item。

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截取整个RecyclerView的，使其是一张完整的图片。思路就是调用每个ItemView的setDrawingCacheEnabled(true)方法，通过View的getDrawingCache()获得Bitmap，然后把这些ItemView 产生的Bitmap保存起来，然后，把这些小的Bitmap整合成一张的大Bitmap。

public static Bitmap shotRecyclerView(RecyclerView view) {
    RecyclerView.Adapter adapter = view.getAdapter();
    Bitmap bigBitmap = null;
    if (adapter != null) {
        int size = adapter.getItemCount();
        int height = 0;
        Paint paint = new Paint();
        int iHeight = 0;
        final int maxMemory = (int) (Runtime.getRuntime().maxMemory() / 1024);
        // Use 1/8th of the available memory for this memory cache.
        final int cacheSize = maxMemory / 8;
        //这个地方用LruCache显得高大上，实际上用个List也是可以的
        LruCache<String, Bitmap> bitmapCache = new LruCache<>(cacheSize);
        for (int i = 0; i < size; i++) {
            RecyclerView.ViewHolder holder = adapter.createViewHolder(view, adapter.getItemViewType(i));
            adapter.onBindViewHolder(holder, i);
            holder.itemView.measure(
                    View.MeasureSpec.makeMeasureSpec(view.getWidth(), View.MeasureSpec.EXACTLY),
                    View.MeasureSpec.makeMeasureSpec(0, View.MeasureSpec.UNSPECIFIED));
            holder.itemView.layout(0, 0, holder.itemView.getMeasuredWidth(),
                    holder.itemView.getMeasuredHeight());
            holder.itemView.setDrawingCacheEnabled(true);
            holder.itemView.buildDrawingCache();
            Bitmap drawingCache = holder.itemView.getDrawingCache();
            if (drawingCache != null) {
                bitmapCache.put(String.valueOf(i), drawingCache);
            }
            height += holder.itemView.getMeasuredHeight();
        }
        // 这个地方容易出现OOM，关键是要看截取RecyclerView的展开的宽高
        bigBitmap = Bitmap.createBitmap(view.getMeasuredWidth(), height, Bitmap.Config.ARGB_8888);
        Canvas bigCanvas = new Canvas(bigBitmap);
        Drawable lBackground = view.getBackground();
        //先画RecyclerView的背景色
        if (lBackground instanceof ColorDrawable) {
            ColorDrawable lColorDrawable = (ColorDrawable) lBackground;
            int lColor = lColorDrawable.getColor();
            bigCanvas.drawColor(lColor);
        }
        for (int i = 0; i < size; i++) {
            Bitmap bitmap = bitmapCache.get(String.valueOf(i));
            bigCanvas.drawBitmap(bitmap, 0f, iHeight, paint);
            iHeight += bitmap.getHeight();
            bitmap.recycle();
        }
    }
    return bigBitmap;
}