NullPointerException在oppo设备上无法找到可绘制的位图

Question

我试图从可绘制的imageview和调整它的大小，我目前的代码是在所有设备上工作，除了在oppo设备它崩溃在crop()方法

我得到的崩溃是在庄稼()方法的第一行，你可以在

下面找到

Caused by: java.lang.NullPointerException: 

我的当前代码是:

public Bitmap getTileBitmap(int id, int size) {
String string = tileUrls.get(id);
if (string.contains(Themes.URI_DRAWABLE)) {
String drawableResourceName = string.substring(Themes.URI_DRAWABLE.length());
int drawableResourceId = Shared.context.getResources().getIdentifier(drawableResourceName, "drawable", Shared.context.getPackageName());
Bitmap bitmap = Utils.scaleDown(drawableResourceId, size, size);
return Utils.crop(bitmap, size, size);
}
return null;
}

public static Bitmap crop(Bitmap source, int newHeight, int newWidth) {
int sourceWidth = source.getWidth();
int sourceHeight = source.getHeight();
float xScale = (float) newWidth / sourceWidth;
float yScale = (float) newHeight / sourceHeight;
float scale = Math.max(xScale, yScale);
float scaledWidth = scale * sourceWidth;
float scaledHeight = scale * sourceHeight;
float left = (newWidth - scaledWidth) / 2;
float top = (newHeight - scaledHeight) / 2;
RectF targetRect = new RectF(left, top, left + scaledWidth, top + scaledHeight);
Bitmap dest = Bitmap.createBitmap(newWidth, newHeight, source.getConfig());
Canvas canvas = new Canvas(dest);
canvas.drawBitmap(source, null, targetRect, null);
return dest;
}

编辑:增加了可能导致问题的缩放方法

public static Bitmap scaleDown(int resource, int reqWidth, int reqHeight) {
BitmapFactory.Options options = new BitmapFactory.Options();
options.inJustDecodeBounds = true;
BitmapFactory.decodeResource(Shared.context.getResources(), resource);
// Calculate inSampleSize
options.inSampleSize = calculateInSampleSize(options, reqWidth, reqHeight);
// Decode bitmap with inSampleSize set
options.inJustDecodeBounds = false;
return BitmapFactory.decodeResource(Shared.context.getResources(), resource, options);
}

到目前为止，我还不确定是什么导致了oppo设备的崩溃

Answer 1

试试这个:

options.inJustDecodeBounds = true;
options.inScaled = false;
options.inDensity = 0;
options.inMutable = true; //API 11. Pass to canvas? Might crash without this.
//Load the image here... BitmapFactory.decodeResource()...
... //Some calculations.
options.inJustDecodeBounds = false;
options.inPreferredConfig = Bitmap.Config.ARGB_8888;