Question

我有以下代码用于在我的android网格视图中显示几个url图像。问题是，在网格视图中显示少量图像需要花费大量时间。这些是我的代码：

public class GridViewImageAdapter extends BaseAdapter {
private Activity activity;
private ArrayList<HashMap<String, String>> galleryAttributes = new ArrayList<HashMap<String, String>>();
private int imageWidth;
int ctr = 0;

public GridViewImageAdapter(Activity activity,
        ArrayList<HashMap<String, String>> galleryAttributes, int imageWidth) {
    this.activity = activity;
    this.galleryAttributes = galleryAttributes;
    this.imageWidth = imageWidth;
}

@Override
public int getCount() {
    // TODO Auto-generated method stub
    return galleryAttributes.size();
}

@Override
public Object getItem(int position) {
    // TODO Auto-generated method stub
    return galleryAttributes.get(position);
}

@Override
public long getItemId(int position) {
    // TODO Auto-generated method stub
    return position;
}

@Override
public View getView(int position, View convertView, ViewGroup parent) {
    // TODO Auto-generated method stub


    ImageView imageView;
    if(convertView == null){
        imageView = new ImageView(activity);
    }else{
        imageView = (ImageView) convertView;
    }

    LoadImage loadImage = new LoadImage();

    try {
        Bitmap image = loadImage.execute(galleryAttributes.get(position).get("Link")).get();
        imageView.setScaleType(ImageView.ScaleType.CENTER_CROP);
        imageView.setLayoutParams(new GridView.LayoutParams(imageWidth, imageWidth));
        imageView.setImageBitmap(image);

    } catch (InterruptedException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    } catch (ExecutionException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    }   

    return imageView;   
}


public class LoadImage extends AsyncTask<String, String, Bitmap>{

    @Override
    protected Bitmap doInBackground(String... params) {
        // TODO Auto-generated method stub
        try{
            BitmapFactory.Options o = new BitmapFactory.Options();
            o.inJustDecodeBounds = true;
            BitmapFactory.decodeStream((InputStream) new URL(params[0]).getContent(), null, o);
            final int REQUIRED_WIDTH = imageWidth;
            final int REQUIRED_HEIGHT = imageWidth;
            int scale = 1;
            while (o.outWidth / scale / 2 >= REQUIRED_WIDTH
                    && o.outHeight / scale / 2 >= REQUIRED_HEIGHT)
                scale *= 2;
            BitmapFactory.Options o2 = new BitmapFactory.Options();
            o2.inSampleSize = scale;
            return BitmapFactory.decodeStream((InputStream) new URL(params[0]).getContent(), null, o2);
        }

        catch(Exception e){
            e.printStackTrace();
        }
        return null;
    }   
}

Answer 1

尝试使用毕加索

http://square.github.io/picasso/

这个库将缓存从URL下载的图片，下次打开它时，它会加载得更快，因为你不需要再次下载它，只需从缓存中取出它。

如果初始显示也很慢，请尝试将其调整为合理的大小。

用法也很简单：

Picasso.with(context)
  .load(url)
  .resize(50, 50)
  .centerCrop()
  .into(imageView)

Answer 2

您可以使用Glide或Picasso。但Glide也有缩略图支持。

Glide.with（本） .load（galleryAttributes.get（位置）获得（ “链接”）） .thumbnail（0.1F） .into（ImageView的）;

Picasso.with（本）.load（galleryAttributes.get（位置）获得（ “链接”））代入（ImageView的）。

如何将图像URL快速加载到android网格视图中？

2 个答案: