我按照本教程http://mobile.tutsplus.com/tutorials/android/android-user-interface-design-horizontal-view-paging/
我有一个看起来像这样的寻呼机适配器(下面的代码),我收到一条错误消息,说我的图像太大。( java.lang.OutOfMemoryError: 位图大小超出 VM 预算。 )
我知道很多人问过这个问题,我用谷歌搜索并找到了很多解决方案。但是,我似乎无法正确运行它。我是新手,希望能在这里得到一些答案,因为我不知道我还能做什么。
位图解码适用于图像,但如果我的图像采用如下布局怎么办。如何缩小图像?
public class TutorialPagerAdapter extends PagerAdapter {
Activity activity;
int imageArray[];
private Resources resource;
private class MyPagerAdapter extends PagerAdapter {
public int getCount() {
return 5;
}
public Object instantiateItem(View collection, int position) {
LayoutInflater inflater = (LayoutInflater) collection.getContext()
.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
int resId = 0;
switch (position) {
case 0:
resId = R.layout.farleft;
try{
mImageView = (ImageView) collection.findViewById(R.id.tutorial);
mImageView.setImageBitmap(decodeSampledBitmapFromResource(activity.getResources(), R.id.tutorial, 100, 100));
}
catch (NullPointerException e)
{
e.printStackTrace();
}
break;
case 1:
resId = R.layout.left;
break;
case 2:
resId = R.layout.middle;
break;
case 3:
resId = R.layout.right;
break;
case 4:
resId = R.layout.farright;
break;
}
View view = inflater.inflate(resId, null);
((ViewPager) collection).addView(view, 0);
return view;
}
@Override
public void destroyItem(View arg0, int arg1, Object arg2) {
((ViewPager) arg0).removeView((View) arg2);
}
@Override
public boolean isViewFromObject(View arg0, Object arg1) {
return arg0 == ((View) arg1);
}
@Override
public Parcelable saveState() {
return null;
}
public static Bitmap decodeSampledBitmapFromResource(String res, int reqWidth, int reqHeight) {
// First decode with inJustDecodeBounds=true to check dimensions
final BitmapFactory.Options options = new BitmapFactory.Options();
options.inJustDecodeBounds = true;
BitmapFactory.decodeFile(res, options);
// Calculate inSampleSize
options.inSampleSize = calculateInSampleSize(options, reqWidth, reqHeight);
// Decode bitmap with inSampleSize set
options.inJustDecodeBounds = false;
return BitmapFactory.decodeFile(res, options);
}
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;}
}
编辑
我试过mImageView.setImageBitmap(decodeSampledBitmapFromResource...)
了,但我在这一行得到了空指针异常。