设置outWidth和outHeight而不是inSampleSize来解码位图有什么危险

Question

要在android中调整位图大小，我正在考虑做

BitmapFactory.Options options = new BitmapFactory.Options();
options.inSampleSize = 1;
options.inJustDecodeBounds = true;
BitmapFactory.decodeFile(filepath, options);
// options.inSampleSize = ImageResizer.calculateInSampleSize(options, x, y);
options.outWidth = x;
options.outHeight = y;
options.inJustDecodeBounds = false;
Bitmap bmp = BitmapFactory.decodeFile(filepath, options);

请注意哪条线被注释掉了。我的方法与更常见的

有何不同（比较和对比）

BitmapFactory.Options options = new BitmapFactory.Options();
options.inSampleSize = 1;
options.inJustDecodeBounds = true;
BitmapFactory.decodeFile(filepath, options);
options.inSampleSize = ImageResizer.calculateInSampleSize(options, x, y);
// options.outWidth = x;
// options.outHeight = y;
options.inJustDecodeBounds = false;
Bitmap bmp = BitmapFactory.decodeFile(filepath, options);

如果我保留所有这些怎么样？如在

BitmapFactory.Options options = new BitmapFactory.Options();
options.inSampleSize = 1;
options.inJustDecodeBounds = true;
BitmapFactory.decodeFile(filepath, options);
options.inSampleSize = ImageResizer.calculateInSampleSize(options, x, y);
options.outWidth = x;
options.outHeight = y;
options.inJustDecodeBounds = false;
Bitmap bmp = BitmapFactory.decodeFile(filepath, options);

Answer 1

  

设置outWidth和outHeight而不是inSampleSize来解码位图有什么危险

outWidth和outHeight是输出值。它们不是输入值。自己设置它们没有任何用处。