java 如何修复“画布：尝试使用回收位图错误”？
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How to fix "canvas: trying to use a recycled bitmap error"?
提问by Jahir Fiquitiva
I'm creating a RecyclerViewto show a Grid of pictures. When selecting one of them, it should open a new activity with a transition.
我正在创建一个RecyclerView来显示图片网格。选择其中一个时，它应该打开一个过渡的新活动。
I'm using Glide library to load the pictures and the transition looks awful because it reloads the picture in the new activity. So I had to save it in cache, and then use it for the transition.
我正在使用 Glide 库加载图片，过渡看起来很糟糕，因为它在新活动中重新加载图片。所以我不得不将它保存在缓存中，然后将其用于过渡。
I have the code, but sometimes if the picture doesn't load, it throws a Canvas RuntimeException.
我有代码，但有时如果图片没有加载，它会抛出一个 Canvas RuntimeException。
This is the log:
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)
This is the code to open the other activity and save the picture as cache:
这是打开另一个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;
}
What could I do to fix this issue? Thanks in advance.
我能做些什么来解决这个问题？提前致谢。
回答by AndroidEx
I suspect that once in a while your bitmap gets into the recycled state just before the Canvasgets a chance to draw onto it here drawable.draw(canvas);.
我怀疑您的位图偶尔会Canvas在有机会在这里绘制之前进入回收状态drawable.draw(canvas);。
A quick solution should be not to call bitmap.recycle();, which is not strictly required for android >2.3.3. If you still want to reclaim this memory forcefully, you'll have to find a way to check when the bitmap is indeed no longer needed (i.e., Canvashad a chance to finish its drawing operations).
一个快速的解决方案应该是不要调用bitmap.recycle();，这对于android >2.3.3不是严格要求的。如果您仍然想强行回收此内存，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）。
回答by sakiM
Move bitmap.recycle();to another place in the code where this bitmap is really no longer needed.
移动bitmap.recycle();到在其中确实不再需要该位的代码另一个地方。
回答by James Fenn
I don't know much about canvas (I don't use animations that often) but if you don't find any way to fix this, you could try using this library instead: https://github.com/codepath/android_guides/wiki/shared-element-activity-transition
我对画布不太了解（我不经常使用动画）但如果你找不到任何方法来解决这个问题，你可以尝试使用这个库：https: //github.com/codepath/android_guides /wiki/shared-element-activity-transition
