位图的 ListView 内存不足

Question

我让用户在 ImageView 上绘制东西，然后单击保存以保存绘图。稍后，用户可以在一个 ListView 中看到所有保存的绘图，该 ListView 具有一个 ImageView 和两个带有一些细节的 TextView。

为避免保存和检索位图，我将绘制的所有 xy 点存储在 txt 文件中，并在使用 createBitmap 方法绘制点并在适配器内的 ImageView 上设置位图时重新创建位图。

当用户删除或更新列表时，我完成并重新启动列表活动以重新加载文件并重新创建所有这些位图，但以前的位图没有被回收，因为我不知道在哪里调用回收方法！！

所以问题自然是有时我会因为所有位图而出现 OutOfMemory 错误。 问题：我在哪里可以为位图调用回收，或者我如何在不使用这么多内存的情况下实现它 这是列表适配器

public class CustomGalleryListAdapter extends ArrayAdapter<String>{
private final Activity context;
private final String[] name_plus_details;
private final String[] imageinfo;
public CustomGalleryListAdapter(Activity context,
String[] name_plus_details, String[] imageinfo) {
super(context, R.layout.gallery_list_single_item_layout, name_plus_details);
this.context = context;
this.name_plus_details = name_plus_details;
this.imageinfo = imageinfo;
}
@Override
public View getView(int position, View view, ViewGroup parent) {
    Paint mPaint,mPaint2;
    mPaint = new Paint();
    mPaint.setAntiAlias(true);
    mPaint.setDither(true);
    mPaint.setColor(Color.BLUE);
    mPaint.setStyle(Paint.Style.STROKE);
    mPaint.setStrokeJoin(Paint.Join.ROUND);
    mPaint.setStrokeCap(Paint.Cap.ROUND);
    mPaint.setStrokeWidth(23/4);

    mPaint2 = new Paint();
    mPaint2.setAntiAlias(true);
    mPaint2.setDither(true);
    mPaint2.setColor(Color.GREEN);
    mPaint2.setStyle(Paint.Style.STROKE);
    mPaint2.setStrokeJoin(Paint.Join.ROUND);
    mPaint2.setStrokeCap(Paint.Cap.ROUND);
    mPaint2.setStrokeWidth(17/4);


    LayoutInflater inflater = context.getLayoutInflater();
    Bitmap mBitmap = Bitmap.createBitmap(600/5, 700/5, Bitmap.Config.ARGB_8888);
    Canvas mCanvas = new Canvas(mBitmap);
    String[] imagedata = imageinfo[position].split(":");
    String[] points;
    for(int i=0;i<imagedata.length;i++){
        if(imagedata[i].contains(";")){
            points=imagedata[i].split(";");
            if(points[0].length()>0){
                int drawx1 = Integer.parseInt(points[0].split(",")[0]);
                int drawy1 = Integer.parseInt(points[0].split(",")[1]);
                mCanvas.drawCircle(drawx1/5, drawy1/5, 15/4, mPaint2);
            }
            for(int h=0;h+1<points.length-1;h++){
                int drawx1 = Integer.parseInt(points[h].split(",")[0]);
                int drawy1 = Integer.parseInt(points[h].split(",")[1]);
                int drawx2 = Integer.parseInt(points[h+1].split(",")[0]);
                int drawy2 = Integer.parseInt(points[h+1].split(",")[1]);
                mCanvas.drawLine(drawx1/5, drawy1/5, drawx2/5, drawy2/5, mPaint);
            }
        }
    }
    View rowView= inflater.inflate(R.layout.gallery_list_single_item_layout, null, true);
    TextView detailsTextView = (TextView) rowView.findViewById(R.id.txt);
    TextView name_field = (TextView) rowView.findViewById(R.id.gallery_name_field);

    ImageView imageView = (ImageView) rowView.findViewById(R.id.img);
    imageView.setImageDrawable(new BitmapDrawable(getContext().getResources(),mBitmap));
    imageView.setScaleType(ImageView.ScaleType.FIT_XY);      
    imageView.setBackgroundColor(Color.GRAY);
    String[] text_parts = name_plus_details[position].split("ENDNAME");
    name_field.setText(text_parts[0]);
    detailsTextView.setText("\n"+text_parts[1]);

    return rowView;

}
}

Answer 1

首先 - 阅读以下内容： http://developer.android.com/training/displaying-bitmaps/cache-bitmap.html

我认为，据我了解，您已经为您的位图制作了类似图集的东西 - 这看起来好多了。

使用此解决方案还将为您提供一种非常方便的方式来处理位图： http://developer.android.com/reference/android/util/LruCache.html#entryRemoved(boolean, K, V, V)

Answer 2

尝试使用支架，这样您就不会为每个单元格膨胀视图，因为您只是在重复使用它们。看看这个：http://developer.android.com/training/improving-layouts/smooth-scrolling.html#ViewHolder 网上也有很多例子告诉你如何在 ArrayAdapter 中使用 holder