[英]Reducing BitmapDrawable size
I am reducing size of images with this function: 我正在使用此功能缩小图像的大小:
Drawable reduceImageSize (String path)
{
BitmapDrawable bit1 = (BitmapDrawable) Drawable.createFromPath(path);
Bitmap bit2 = Bitmap.createScaledBitmap(bit1.getBitmap(), 640, 360, true);
BitmapDrawable bit3 = new BitmapDrawable(getResources(),bit2);
return bit3;
}
And its working fine, the only problem is when I call this function multiple time the app is getting slow, is there any way to optimize this function? 而且它工作正常,唯一的问题是,当我多次调用该函数使应用程序变慢时,是否有任何方法可以优化此函数? Maybe reducing size via matrix?
也许通过矩阵减小尺寸? Also I am reading images from SD Card and need the back as Drawable for animations, and this function provides this.
另外,我正在从SD卡读取图像,并且需要背面为Drawable进行动画处理,而此功能可提供此功能。
Use BitmapFactory.Options
and inJustDecodeBounds
to scale it down: 使用
BitmapFactory.Options
和inJustDecodeBounds
将其缩小:
Bitmap bitmap = getBitmapFromFile(path, width, height);
public static Bitmap getBitmapFromFile(String path, int width, int height) {
final BitmapFactory.Options options = new BitmapFactory.Options();
options.inJustDecodeBounds = true;
BitmapFactory.decodeFile(path, options);
// Calculate inSampleSize
options.inSampleSize = calculateInSampleSize(options, width, height);
options.inJustDecodeBounds = false;
Bitmap bitmap = BitmapFactory.decodeFile(path, options);
return bitmap;
}
public static int calculateInSampleSize(BitmapFactory.Options options, int reqWidth, int reqHeight) {
// Raw height and width of image
final int height = options.outHeight;
final int width = options.outWidth;
int inSampleSize = 1;
if (height > reqHeight || width > reqWidth) {
if (width > height) {
inSampleSize = Math.round((float)height / (float)reqHeight);
} else {
inSampleSize = Math.round((float)width / (float)reqWidth);
}
}
return inSampleSize;
}
Read more about it here: Loading Large Bitmaps Efficiently 在这里阅读有关它的更多信息: 有效地加载大型位图
Also, I'm not sure where you are calling this method but if you have many of them please make sure you are caching the Bitmaps using LruCache
or similar: Caching Bitmaps 另外,我不确定您在哪里调用此方法,但是如果有很多方法,请确保使用
LruCache
或类似方法来缓存位图 : 缓存位图
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