Question

我有一个从列表中输出json数据的活动。但现在我想在一个片段中实现它。在这个片段中，我想将其视为gridview。这两个文件都运行正常。但是当我尝试实现AsyncTask时，我得到几个redflags作为无法访问的代码。有人可以帮帮我吗？

已编辑：新

    public class SalesFragment extends Fragment {
        GridView gridView;

        @Override
        public View onCreateView(LayoutInflater inflater, ViewGroup container,
                Bundle savedInstanceState) {
            View gv = inflater.inflate(R.layout.hot_sales, null);
            gridView = (GridView) gv.findViewById(R.id.grid_view);
            bindGridview();
            return gv;
        }

        public void bindGridview() {

           new MyAsyncTask(getActivity(),gridView).execute("");
        }

        class MyAsyncTask extends AsyncTask<String, String, String> {
            GridView mGridView;
            Activity mContext;
            Response response;
           public  MyAsyncTask(Activity context,GridView gview) {
             this.mGridView=gview;
             this.mContext=context;
            }

           protected String doInBackground(String... params)  {

               File file = new File( Environment.getExternalStorageDirectory().getAbsolutePath() + "/Android/data/sample.txt");
                if(file.exists()) {
                    try{
                           Reader inputStreamReader = new InputStreamReader(new FileInputStream(file));

                           Gson gson = new Gson();
                           this.response = gson.fromJson(inputStreamReader, Response.class);
                        } catch (FileNotFoundException e) {
                           e.printStackTrace();
                        } catch (@SuppressWarnings("hiding") IOException e){
                           e.printStackTrace();
                        }
                }else{
                    System.out.println("Error");
                }
                return null;
                }

           @Override
           protected void onPostExecute(String result) {

                super.onPostExecute(result);

                //List<HashMap<String,String>> aList = new ArrayList<HashMap<String,String>>();

                for(Sales sales : this.response.sales){
                    HashMap<String, String> hm = new HashMap<String,String>();

                    if (sales.getCategories1().contains("12")){
                        //hm.put("sale_title", "" + sales.getShort_title());
                        for(Shop shop : this.response.shops){
                            String image_file = new String( Environment.getExternalStorageDirectory().getAbsolutePath()
                                    + "/images/" + shop.getImage());
                            if(shop.getId().equals(sales.getShop_id())){
                                hm.put("shop_image", image_file );
                                System.out.println(shop_image);
                            }
                        }

                  if(hm.size()>0){
                        gridView.setAdapter(new ImageAdapter(MainActivity.this,R.layout.grid_layout , imgArray, titleArray));
                             }
                    }
                }



           }
        }
    }

如何在上面的图像上调用图像到gridview？请帮忙。

Answer 1

在片段

中有一个简单的步骤来创建asyntask

在activityCreateview

上的代码放置代码中

new MyAsyncTask(getActivity(), mListView).execute("");

getActivity()是与片段和活动进行通信的方法

在asynstak的帖子

context.mListView.setArrayAdapter(...........)

这是

public class SalesFragment extends Fragment {
GridView gridView;
    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
            Bundle savedInstanceState) {
        View gv = inflater.inflate(R.layout.hot_sales, null);
       gridView = (GridView) gv.findViewById(R.id.grid_view);
        bindGridView()
        return gv;
        //return super.onCreateView(inflater, container, savedInstanceState);
    }

public void bindGridview()
{

   new MyAsyncTask(getActivity(), gridView).execute("");
}

class MyAsyncTask extends AsyncTask<String, String, String>
{
    GridView mGridView;
    Activity mContex;
   public  MyAsyncTask(Activity contex,GridView gview)
    {
     this.mGridView=gview;
     this.mContex=contex;
    }

   protected String doInBackground(String... params)
    {

       //fetch data
    }

   @Override
    protected void onPostExecute(String result) {
      {   

        for(Sales sales : this.response.sales){
            HashMap<String, String> hm = new HashMap<String,String>();

            if (sales.getCategories1().contains("12")){
                //hm.put("sale_title", "" + sales.getShort_title());
                for(Shop shop : this.response.shops){
                    String image_file = new String(        Environment.getExternalStorageDirectory().getAbsolutePath()
                            + "/images/" + shop.getImage());
                    if(shop.getId().equals(sales.getShop_id())){
                        hm.put("shop_image", image_file );
                        System.out.println(shop_image);
                    }
                }
            }
        }
               if(hm.size()>0)
              mcontext.mGridView.setAdapter(new ImageAdapter(mContext),hm);
      }

在获取数据之前使其模型像

public class ImageModel
    {
        String title;
        String img;
    }


ArrayList<ImageModel> arrayList=new ArrayList<ImageModel>();

用所需数据填充数组列表然后

mcontext.mGridView.setAdapter(new ImageAdapter(mContext),hm,arrayList);

//in image adapter

public class ImageAdapter extends ArrayAdapter<String> {

public ImageAdapter(Context context, HashMap<String, String> hm,ArrayList<ImageModel> images ) 
        {
            super(context, R.layout.activity_t);

        }
//--code
   }

在适配器中使用哈希映射并为位置分配图像设置数据并从模型中获取值

在Fragment android中实现AsyncTask

1 个答案: