Android将一个View转为Bitmap的两种方式

方式一：新建Bitmap，将View中内容绘制到Bitmap上

public static Bitmap createBitmapFromView(View view) {
      //是ImageView直接获取
        if (view instanceof ImageView) {
            Drawable drawable = ((ImageView) view).getDrawable();
            if (drawable instanceof BitmapDrawable) {
                return ((BitmapDrawable) drawable).getBitmap();
            }
        }
        view.clearFocus();
        Bitmap bitmap = Bitmap.createBitmap(view.getWidth(), view.getHeight(), Bitmap.Config.ARGB_8888);
        if (bitmap != null) {
            Canvas canvas = new Canvas(bitmap);
            view.draw(canvas);
            canvas.setBitmap(null);
        }
        return bitmap;
}

方式二：直接从View缓存cache中取

/**
   * 该方式原理主要是：View组件显示的内容可以通过cache机制保存为bitmap
     */
    public static Bitmap createBitmapFromView(View view) {
        Bitmap bitmap = null;
        //开启view缓存bitmap
        view.setDrawingCacheEnabled(true);
        //设置view缓存Bitmap质量
        view.setDrawingCacheQuality(DRAWING_CACHE_QUALITY_HIGH);
        //获取缓存的bitmap
        Bitmap cache = view.getDrawingCache();
        if (cache != null && !cache.isRecycled()) {
            bitmap = Bitmap.createBitmap(cache);
        }
        //销毁view缓存bitmap
        view.destroyDrawingCache();
        //关闭view缓存bitmap
        view.setDrawingCacheEnabled(false);
        return bitmap;
    }