为什么不能从AsyncTask加载位图？

Question

我正在尝试使用AsyncTask加载位图，以将其加载到UI线程之外，因为它太慢了。不幸的是，启动应用程序时出现问题。

AsyncTask是在“ BitmapBank”类内部声明的类，用于处理应用程序的不同位图。我这样做是为了避免您无法从Asynctask返回某些信息。

这是我的代码：

    public Bitmap loadBitmap(Drawable drawable){
        Bitmap bitmap = Bitmap.createBitmap(drawable.getIntrinsicWidth(), drawable.getIntrinsicHeight(), Bitmap.Config.ARGB_8888);
        drawable.setBounds(0, 0, drawable.getIntrinsicWidth(), drawable.getIntrinsicHeight());
        Canvas canvas = new Canvas(bitmap);
        drawable.draw(canvas);
        return bitmap;
    }

    private Bitmap scaleImage(Bitmap bitmap, int ratio){
        float widthHeightRatio = (float)(bitmap.getHeight())/(float)(bitmap.getWidth());
        int scaleHeight = (int)(widthHeightRatio * AppConstants.SCREEN_WIDTH/ratio);
        return Bitmap.createScaledBitmap(bitmap, AppConstants.SCREEN_WIDTH/ratio, scaleHeight, false);
    }

    private class BitmapTask extends AsyncTask<Drawable, Void, Void> {

        public BitmapTask(){
            super();
        }

        @Override
        protected Void doInBackground(Drawable... drawables) {
            rocket = prepareBitmap(drawables[0]);
            astronaut = prepareBitmap(drawables[1]);
            bloc = prepareBitmap(drawables[2]);
            background = prepareBitmap(drawables[3]);

            return null;
        }

        @Override
        protected void onPostExecute(Void aVoid) {
            rocket = scaleImage(rocket, 10);
            astronaut = scaleImage(astronaut, 20);
            bloc = scaleImage(bloc, AppConstants.NB_BLOCS);
            background = scaleImage(background, 1);
        }
    }

这是日志猫：

Caused by: java.lang.OutOfMemoryError: Failed to allocate a 121701132 byte allocation with 16777216 free bytes and 86MB until OOM
        at dalvik.system.VMRuntime.newNonMovableArray(Native Method)
        at android.graphics.Bitmap.nativeCreate(Native Method)
        at android.graphics.Bitmap.createBitmap(Bitmap.java:975)
        at android.graphics.Bitmap.createBitmap(Bitmap.java:946)
        at android.graphics.Bitmap.createBitmap(Bitmap.java:913)
        at com.example.myapplication.BitmapBank.prepareBitmap(BitmapBank.java:93)
        at com.example.myapplication.BitmapBank$BitmapTask.doInBackground(BitmapBank.java:117)
        at com.example.myapplication.BitmapBank$BitmapTask.doInBackground(BitmapBank.java:106)
        at android.os.AsyncTask$2.call(AsyncTask.java:295)
        at java.util.concurrent.FutureTask.run(FutureTask.java:237)
        at android.os.AsyncTask$SerialExecutor$1.run(AsyncTask.java:234) 
        at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1113) 
        at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:588) 
        at java.lang.Thread.run(Thread.java:818)

感谢您可以看看！

Answer 1

我建议您使用自动处理问题的“ Glide”库。 Glide是一个开放源代码的Android库，用于加载动画图像，视频和GIF。使用Glide，您可以上传和显示来自许多不同来源的媒体，例如远程服务器或本地文件系统。