如何解决“画布：尝试使用回收的位图错误”？

Question

我正在创建一个RecyclerView以显示图片网格。选择其中一个时，它应打开一个带有过渡的新活动。

我正在使用Glide库加载图片，并且过渡效果很糟糕，因为它在新活动中重新加载了图片。因此，我必须将其保存在缓存中，然后将其用于过渡。

我有代码，但有时如果图片未加载，则会抛出Canvas RuntimeException。

这是日志：

07-03 15:19:58.633  28461-28461/jahirfiquitiva.project E/AndroidRuntime﹕ FATAL EXCEPTION: main
    Process: jahirfiquitiva.project, PID: 28461
    java.lang.RuntimeException: Canvas: trying to use a recycled bitmap android.graphics.Bitmap@29f09d20
            at android.graphics.Canvas.throwIfCannotDraw(Canvas.java:1282)
            at android.view.GLES20Canvas.drawBitmap(GLES20Canvas.java:599)
            at android.graphics.drawable.BitmapDrawable.draw(BitmapDrawable.java:538)
            at android.widget.ImageView.onDraw(ImageView.java:1176)
            at android.view.View.draw(View.java:15239)
            at android.view.View.updateDisplayListIfDirty(View.java:14175)
            at android.view.View.getDisplayList(View.java:14197)
            at android.view.GhostView.onDraw(GhostView.java:52)
            at android.view.View.draw(View.java:15239)
            at android.view.View.updateDisplayListIfDirty(View.java:14175)
            at android.view.View.getDisplayList(View.java:14197)
            at android.view.View.draw(View.java:14967)
            at android.view.ViewGroup.drawChild(ViewGroup.java:3406)
            at android.view.ViewGroup.dispatchDraw(ViewGroup.java:3199)
            at android.view.View.updateDisplayListIfDirty(View.java:14170)
            at android.view.View.getDisplayList(View.java:14197)
            at android.view.View.draw(View.java:14967)
            at android.view.ViewGroup.drawChild(ViewGroup.java:3406)
            at android.view.ViewGroup.dispatchDraw(ViewGroup.java:3199)
            at android.view.ViewOverlay$OverlayViewGroup.dispatchDraw(ViewOverlay.java:219)
            at android.view.View.draw(View.java:15248)
            at android.widget.FrameLayout.draw(FrameLayout.java:598)
            at com.android.internal.policy.impl.PhoneWindow$DecorView.draw(PhoneWindow.java:2906)
            at android.view.View.updateDisplayListIfDirty(View.java:14175)
            at android.view.View.getDisplayList(View.java:14197)
            at android.view.ThreadedRenderer.updateViewTreeDisplayList(ThreadedRenderer.java:273)
            at android.view.ThreadedRenderer.updateRootDisplayList(ThreadedRenderer.java:279)
            at android.view.ThreadedRenderer.draw(ThreadedRenderer.java:318)
            at android.view.ViewRootImpl.draw(ViewRootImpl.java:2536)
            at android.view.ViewRootImpl.performDraw(ViewRootImpl.java:2352)
            at android.view.ViewRootImpl.performTraversals(ViewRootImpl.java:1982)
            at android.view.ViewRootImpl.doTraversal(ViewRootImpl.java:1061)
            at android.view.ViewRootImpl$TraversalRunnable.run(ViewRootImpl.java:5891)
            at android.view.Choreographer$CallbackRecord.run(Choreographer.java:767)
            at android.view.Choreographer.doCallbacks(Choreographer.java:580)
            at android.view.Choreographer.doFrame(Choreographer.java:550)
            at android.view.Choreographer$FrameDisplayEventReceiver.run(Choreographer.java:753)
            at android.os.Handler.handleCallback(Handler.java:739)
            at android.os.Handler.dispatchMessage(Handler.java:95)
            at android.os.Looper.loop(Looper.java:135)
            at android.app.ActivityThread.main(ActivityThread.java:5289)
            at java.lang.reflect.Method.invoke(Native Method)
            at java.lang.reflect.Method.invoke(Method.java:372)
            at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:904)
            at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:699)

这是打开其他活动并将图片保存为缓存的代码：

private void openViewer(WallpapersAdapter.WallsHolder wallsHolder, int index, final HashMap<String, String> data) {

        final Intent intent = new Intent(wallsActivity, ViewerActivity.class);
        intent.putExtra("wallUrl", data.get(WallpapersActivity.WALL));
        intent.putExtra("wallName", data.get(WallpapersActivity.NAME));
        intent.putExtra("transitionName", ViewCompat.getTransitionName(wallsHolder.wall));

        //save image from drawable
        //get its path and send it to activity
        Bitmap bitmap = drawableToBitmap(wallsHolder.wall.getDrawable());
        //Convert to byte array and send to the other activity

        Log.e("Resolution", bitmap.getWidth() + "x" + bitmap.getHeight());
        try {
            //Write file
            String filename = "bitmap.png";
            FileOutputStream stream = this.openFileOutput(filename, Context.MODE_PRIVATE);
            bitmap.compress(Bitmap.CompressFormat.PNG, 100, stream);

            //Cleanup
            stream.close();
            bitmap.recycle();

            //Pop intent
            intent.putExtra("image", filename);
        } catch (Exception e) {
            e.printStackTrace();
        }

        ActivityOptionsCompat options = ActivityOptionsCompat.makeSceneTransitionAnimation(
                this, wallsHolder.wall, ViewCompat.getTransitionName(wallsHolder.wall));
        startActivity(intent, options.toBundle());

    }

    public static Bitmap drawableToBitmap (Drawable drawable) {
        Bitmap bitmap = null;
        if (drawable instanceof BitmapDrawable) {
            BitmapDrawable bitmapDrawable = (BitmapDrawable) drawable;
            if(bitmapDrawable.getBitmap() != null) {
                return bitmapDrawable.getBitmap();
            }
        }

        if(drawable.getIntrinsicWidth() <= 0 || drawable.getIntrinsicHeight() <= 0) {
            bitmap = Bitmap.createBitmap(1, 1, Bitmap.Config.ARGB_8888); // Single color bitmap will be created of 1x1 pixel
        } else {
            bitmap = Bitmap.createBitmap(drawable.getIntrinsicWidth(), drawable.getIntrinsicHeight(), Bitmap.Config.ARGB_8888);
        }

        Canvas canvas = new Canvas(bitmap);
        drawable.setBounds(0, 0, drawable.getIntrinsicWidth(), drawable.getIntrinsicHeight());
        drawable.draw(canvas);
        return bitmap;
    }

我该怎么做才能解决此问题？提前致谢。

Answer 1

我怀疑您的位图偶尔会进入回收状态，然后Canvas才有机会在此处使用它drawable.draw(canvas);。

一个快速的解决方案应该是不调用bitmap.recycle();，这对于android>
2.3.3
并不是严格要求的。如果仍然要强制回收该内存，则必须找到一种方法来检查何时确实不再需要位图（即，Canvas有机会完成其绘制操作）。