如何使用pulltorefresh類在Gridview中顯示圖像

Question

我通常可以在gridview中顯示圖像。但是，我想使用pulltorefresh功能，並且我找到了一個庫來獲取功能。我很困惑如何整合我的圖像。

現在，gridview只顯示圖像鏈接在數組中。我如何使用imageAdapter而不是arrayAdapter來顯示圖像？

非常感謝。

這是活動類：

public final class PullToRefreshGridActivity extends Activity { 

static final int MENU_SET_MODE = 0; 

private LinkedList<String> mListItems; 
private PullToRefreshGridView mPullRefreshGridView; 
private GridView mGridView; 
private ArrayAdapter<String> mAdapter; 

/** Called when the activity is first created. */ 
@Override 
public void onCreate(Bundle savedInstanceState) { 
    super.onCreate(savedInstanceState); 
    setContentView(R.layout.activity_ptr_grid); 

    mPullRefreshGridView = (PullToRefreshGridView) findViewById(R.id.pull_refresh_grid); 
    mGridView = mPullRefreshGridView.getRefreshableView(); 

    // Set a listener to be invoked when the list should be refreshed. 
    mPullRefreshGridView.setOnRefreshListener(new OnRefreshListener2<GridView>() { 

     @Override 
     public void onPullDownToRefresh(PullToRefreshBase<GridView> refreshView) { 
      Toast.makeText(PullToRefreshGridActivity.this, "Pull Down!", Toast.LENGTH_SHORT).show(); 
      new GetDataTask().execute(); 
     } 

     @Override 
     public void onPullUpToRefresh(PullToRefreshBase<GridView> refreshView) { 
      Toast.makeText(PullToRefreshGridActivity.this, "Pull Up!", Toast.LENGTH_SHORT).show(); 
      new GetDataTask().execute(); 
     } 

    }); 

    mListItems = new LinkedList<String>(); 

    TextView tv = new TextView(this); 
    tv.setGravity(Gravity.CENTER); 
    tv.setText("Empty View, Pull Down/Up to Add Items"); 
    mPullRefreshGridView.setEmptyView(tv); 

    mAdapter = new ArrayAdapter<String>(this, android.R.layout.simple_list_item_1, mListItems); 
    mGridView.setAdapter(mAdapter); 
} 

private class GetDataTask extends AsyncTask<Void, Void, String[]> { 

    @Override 
    protected String[] doInBackground(Void... params) { 
     // Simulates a background job. 
     try { 
      Thread.sleep(2000); 
     } catch (InterruptedException e) { 
     } 
     return mStrings; 
    } 

    @Override 
    protected void onPostExecute(String[] result) { 
     mListItems.addFirst("Added after refresh..."); 
     mListItems.addAll(Arrays.asList(result)); 
     mAdapter.notifyDataSetChanged(); 

     // Call onRefreshComplete when the list has been refreshed. 
     mPullRefreshGridView.onRefreshComplete(); 

     super.onPostExecute(result); 
    } 
} 

@Override 
public boolean onCreateOptionsMenu(Menu menu) { 
    menu.add(0, MENU_SET_MODE, 0, 
      mPullRefreshGridView.getMode() == Mode.BOTH ? "Change to MODE_PULL_DOWN" 
        : "Change to MODE_PULL_BOTH"); 
    return super.onCreateOptionsMenu(menu); 
} 

@Override 
public boolean onPrepareOptionsMenu(Menu menu) { 
    MenuItem setModeItem = menu.findItem(MENU_SET_MODE); 
    setModeItem.setTitle(mPullRefreshGridView.getMode() == Mode.BOTH ? "Change to MODE_PULL_FROM_START" 
      : "Change to MODE_PULL_BOTH"); 

    return super.onPrepareOptionsMenu(menu); 
} 

@Override 
public boolean onOptionsItemSelected(MenuItem item) { 
    switch (item.getItemId()) { 
     case MENU_SET_MODE: 
      mPullRefreshGridView 
        .setMode(mPullRefreshGridView.getMode() == Mode.BOTH ? Mode.PULL_FROM_START 
          : Mode.BOTH); 
      break; 
    } 

    return super.onOptionsItemSelected(item); 
} 

private String[] mStrings = {"https://lh6.googleusercontent.com/-55osAWw3x0Q/URquUtcFr5I/AAAAAAAAAbs/rWlj1RUKrYI/s1024/A%252520Photographer.jpg", 
     "https://lh4.googleusercontent.com/--dq8niRp7W4/URquVgmXvgI/AAAAAAAAAbs/-gnuLQfNnBA/s1024/A%252520Song%252520of%252520Ice%252520and%252520Fire.jpg", 
     "https://lh5.googleusercontent.com/-7qZeDtRKFKc/URquWZT1gOI/AAAAAAAAAbs/hqWgteyNXsg/s1024/Another%252520Rockaway%252520Sunset.jpg", 
     "https://lh3.googleusercontent.com/--L0Km39l5J8/URquXHGcdNI/AAAAAAAAAbs/3ZrSJNrSomQ/s1024/Antelope%252520Butte.jpg", 
     "https://lh6.googleusercontent.com/-8HO-4vIFnlw/URquZnsFgtI/AAAAAAAAAbs/WT8jViTF7vw/s1024/Antelope%252520Hallway.jpg", 
     "https://lh4.googleusercontent.com/-WIuWgVcU3Qw/URqubRVcj4I/AAAAAAAAAbs/YvbwgGjwdIQ/s1024/Antelope%252520Walls.jpg", 
     "https://lh6.googleusercontent.com/-UBmLbPELvoQ/URqucCdv0kI/AAAAAAAAAbs/IdNhr2VQoQs/s1024/Apre%2525CC%252580s%252520la%252520Pluie.jpg", 
     "https://lh3.googleusercontent.com/-s-AFpvgSeew/URquc6dF-JI/AAAAAAAAAbs/Mt3xNGRUd68/s1024/Backlit%252520Cloud.jpg", 
     "https://lh5.googleusercontent.com/-bvmif9a9YOQ/URquea3heHI/AAAAAAAAAbs/rcr6wyeQtAo/s1024/Bee%252520and%252520Flower.jpg", 
     "https://lh5.googleusercontent.com/-n7mdm7I7FGs/URqueT_BT-I/AAAAAAAAAbs/9MYmXlmpSAo/s1024/Bonzai%252520Rock%252520Sunset.jpg", 
     "https://lh6.googleusercontent.com/-4CN4X4t0M1k/URqufPozWzI/AAAAAAAAAbs/8wK41lg1KPs/s1024/Caterpillar.jpg", 
     "https://lh3.googleusercontent.com/-rrFnVC8xQEg/URqufdrLBaI/AAAAAAAAAbs/s69WYy_fl1E/s1024/Chess.jpg", 
     "https://lh5.googleusercontent.com/-WVpRptWH8Yw/URqugh-QmDI/AAAAAAAAAbs/E-MgBgtlUWU/s1024/Chihuly.jpg",}; 
} 

Answer 1

創建自定義適配器，在那裏你刷新每個細胞。創建一個包含String和Image屬性的對象，在GetDataTask中創建所有這些新對象的ArrayList並刷新您的適配器。

繼承人的適配器的一個簡單的例子和​​目標

public class CustomStepsAdapter extends BaseAdapter { 

    private Context mContext; 
    private ArrayList<CustomObject> details; 
    private LayoutInflater mInflater; 

    public CustomStepsAdapter(Context aContext, ArrayList<CustomObject> data) { 
     this.details = data; 
     this.mContext = aContext; 

     mInflater = LayoutInflater.from(aContext); 
    } 


    public int getCount() { 
     return details.size(); 
    } 

    public CustomObject getItem(int position) { 
     return details.get(position); 
    } 

    public long getItemId(int position) { 
     return position; 
    } 

    public View getView() { 
     return mInflater.inflate(R.layout.custom_step_options_cell, null); 
    } 

    public View getView(int position, View convertView, ViewGroup parent) { 

     final CustomObject item = getItem(position); 

     CustomStepCell cell = null; 
     if (convertView == null) { 
      convertView = getView(); 

      cell = new CustomStepCell(); 

      cell.itemName = (TextView) convertView.findViewById(R.id.option_name); 
      cell.image = (ImageView) convertView.findViewById(R.id.green_checkmark); 

      convertView.setTag(cell); 
     } 
     else 
     { 
      cell = (CustomStepCell) convertView.getTag(); 
     } 

     cell.itemName.setText(item.getItemName()); 
     cell.image = item.getImage(); 


     return convertView; 
    } 

    public boolean isShowPrices() { 
     return showPrices; 
    } 

    public void setShowPrices(boolean showPrices) { 
     this.showPrices = showPrices; 
    } 

    public static class CustomStepCell 
    { 
     public TextView itemName; 
     public ImageView image; 
    } 
} 


public class CustomObject 
{ 
    private String itemName; 
    private ImageView image; 

    public CustomObject() 
    { 
     this.itemName = ""; 
    } 

    public void setImage(ImageView anImage) 
    { 
     this.image = anImage; 
    } 

    public void setItemName(String anItemName) 
    { 
     this.itemName = anItemName; 
    } 

    public ImageView getImage() 
    { 
     return this.image; 
    } 

    public String getItemName() 
    { 
     return this.itemName; 
    } 

}