php - android从mysql数据库中获取图像列表

Question

我可以使用异步任务从 mysql 数据库加载一个图像，但现在我想加载 5 个图像并在 ListView 中显示它们，所以我首先想知道如何使 doInbackground 方法 返回一个从 mysql 数据库中获取的图像列表:

 @Override
        protected Bitmap doInBackground(String... params) {
            String id = params[0];
            String add = "http://192.168.1.11/save/load_image_from_db.php?id=" + id;
            URL url;
            Bitmap image = null;
            try {
                final BitmapFactory.Options options = new BitmapFactory.Options();
                //options.inJustDecodeBounds = true;
                //options.inSampleSize = 4;
                //options.inJustDecodeBounds = false;
                url = new URL(add);
                HttpURLConnection connection = (HttpURLConnection) url.openConnection();
                image = BitmapFactory.decodeStream(connection.getInputStream(),null,options);
            } catch (MalformedURLException e) {
                e.printStackTrace();
            } catch (IOException e) {
                e.printStackTrace();
            }
            return image;
        }

Answer 1

在这种情况下，你必须返回一个图像的 ArrayList，代码将是这样的，(注意:我没有测试过这段代码)

    @Override protected Bitmap doInBackground(String... params) {
     String id = params[0]; 

    String add1 = "http://192.168.1.11/save/load_image_from_db.php?id=" + id; 
    String add2="http://another photo";
    String add3="http://another photo";
    String[] adds={add1, add2, add3};
    URL url;

    ArrayList <Bitmap> imageList=new ArrayList();

     Bitmap image = null; 

    for (int i=0;i<adds.length;i++){

    try { 
    final BitmapFactory.Options options = new BitmapFactory.Options(); null //options.inJustDecodeBounds = true; //options.inSampleSize = 4;  null//options.inJustDecodeBounds = false;

 url = new URL(adds[i]); null HttpURLConnection connection =(HttpURLConnection) url.openConnection();  nullimage = BitmapFactory.decodeStream(connection.getInputStream(),null,options);  null} catch (MalformedURLException e) { e.printStackTrace();  null} catch (IOException e) { e.printStackTrace();  null}

    imageList.add( image);
    image=null;
    }
     return imageList; 
    }