如何在网格视图底部添加进度条页脚？

如何在我的网格视图的底部添加一个进度条页脚，当我加载更多的网格视图项目时可见，并在请求的数据加载完成时隐藏进度栏？我需要知道如何在我的xml文件上实现它的UI，它可以应用于所有屏幕尺寸。下面，是我对我的网格视图代码：如何在网格视图底部添加进度条页脚？

<GridView xmlns:android="http://schemas.android.com/apk/res/android" 
    android:id="@+id/grid_view" 
    android:layout_width="fill_parent" 
    android:layout_height="fill_parent" 
    android:numColumns="auto_fit" 
    android:gravity="center" 
    android:stretchMode="columnWidth" 
    android:background="#ffb4d9"> 
</GridView>

GridViewActivity

public class GridViewActivity extends Activity implements AbsListView.OnScrollListener, AbsListView.OnItemClickListener{ 
    private GridView gridView; 
    private GridViewImageAdapter adapter; 
    private Utils utils; 
    private GenerateData generateData; 
    private ArrayList<HashMap<String, String>> galleryAttributes; 
    private int columnWidth; 
    private int urlPageIndex = 1; 
    private boolean hasRequestedMore; 

    @Override 
    protected void onCreate(Bundle savedInstanceState) { 
     super.onCreate(savedInstanceState); 
     setContentView(R.layout.activity_grid_view); 

     setTitle("Gallery"); 

     gridView = (GridView) findViewById(R.id.grid_view); 
     utils = new Utils(this); 
     InitializeGridLayout(); 

     galleryAttributes = new ArrayList<HashMap<String, String>>(); 
     generateData = utils.new GenerateData(urlPageIndex); 
     try { 
      galleryAttributes.addAll(generateData.execute().get()); 
     } catch (InterruptedException e) { 
      // TODO Auto-generated catch block 
      e.printStackTrace(); 
     } catch (ExecutionException e) { 
      // TODO Auto-generated catch block 
      e.printStackTrace(); 
     } 

     adapter = new GridViewImageAdapter(GridViewActivity.this, galleryAttributes , columnWidth); 
     gridView.setAdapter(adapter); 
     gridView.setOnScrollListener(this); 
     gridView.setOnItemClickListener(this); 

    } 

    public void InitializeGridLayout() { 
     Resources r = getResources(); 
     float padding = TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_DIP,AppConstant.GRID_PADDING, r.getDisplayMetrics()); 
     columnWidth = (int) ((utils.getScreenWidth() - ((AppConstant.NUM_OF_COLUMNS + 1) * padding))/AppConstant.NUM_OF_COLUMNS); 
     gridView.setNumColumns(AppConstant.NUM_OF_COLUMNS); 
     gridView.setColumnWidth(columnWidth); 
     gridView.setStretchMode(GridView.NO_STRETCH); 
     gridView.setPadding((int) padding, (int) padding, (int) padding,(int) padding); 
     gridView.setHorizontalSpacing((int) padding); 
     gridView.setVerticalSpacing((int) padding); 
    } 

    @Override 
    public void onItemClick(AdapterView<?> parent, View view, int position, 
      long id) { 
     // TODO Auto-generated method stub 
     Intent intent = new Intent(GridViewActivity.this, CarouselViewActivity.class); 
     intent.putExtra("position", position); 
     intent.putExtra("galleryAttributes", galleryAttributes); 
     startActivity(intent); 
     Log.e("onItemClick: ", ""+position); 
    } 

    @Override 
    public void onScrollStateChanged(AbsListView view, int scrollState) { 
     // TODO Auto-generated method stub 
     Log.e("onScrollStateChanged: ", ""+scrollState); 
    } 

    @Override 
    public void onScroll(AbsListView view, int firstVisibleItem, 
      int visibleItemCount, int totalItemCount) { 
     // TODO Auto-generated method stub 
     Log.e("onScroll: ","firstVisibleItem:"+firstVisibleItem+" visibleItemCount:"+visibleItemCount+" totalItemCount:"+totalItemCount); 
     if(!hasRequestedMore){ 
      int lastInScreen = firstVisibleItem+visibleItemCount; 
      if(lastInScreen>=totalItemCount){ 
       hasRequestedMore = true; 
       onLoadMoreItems();   
      } 
     } 
    } 

    public void onLoadMoreItems(){ 
     if(urlPageIndex<3){ 
      urlPageIndex++; 
      generateData = utils.new GenerateData(urlPageIndex); 
      try { 
       galleryAttributes.addAll(generateData.execute().get()); 
      } catch (InterruptedException e) { 
       // TODO Auto-generated catch block 
       e.printStackTrace(); 
      } catch (ExecutionException e) { 
       // TODO Auto-generated catch block 
       e.printStackTrace(); 
      } 
      adapter.notifyDataSetChanged(); 
      hasRequestedMore = false; 
     } 
    } 
}

这是我的utils的课，这就是被请求的数据：

public class Utils { 

private Context context; 
private Activity activity; 
private ProgressDialog progress; 

public Utils(){} 

public Utils(Context context){ 
    this.context = context; 
} 

public class GenerateData extends AsyncTask<Void, Void, ArrayList<HashMap<String, String>>>{ 
    private JSONArray dataJsonArr; 
    private JsonParser jParser; 
    private JSONObject json; 
    private JSONObject c; 
    private HashMap<String, String> map; 
    private ArrayList<HashMap<String,String>> galleryAttributes; 
    private int urlPageIndex; 


    public GenerateData(int urlPageIndex){ 
     this.urlPageIndex = urlPageIndex; 
     new InitializeJsonArray().execute(); 
    } 


    @Override 
    protected ArrayList<HashMap<String, String>> doInBackground(
      Void... params) { 
     // TODO Auto-generated method stub 

     try{ 
      for(int i = 0; i< dataJsonArr.length(); i++) 
      { 
       c = dataJsonArr.getJSONObject(i); 
       map = new HashMap<String, String>(); 
       map.put("Link", c.getString("Link")); 
       galleryAttributes.add(map); 
      } 
     } 

     catch (JSONException e) { 
      e.printStackTrace(); 
     } 
     return galleryAttributes; 
    } 

    public class InitializeJsonArray extends AsyncTask<Void, Void, Void>{ 

     @Override 
     protected Void doInBackground(Void... params) { 
      // TODO Auto-generated method stub 
      dataJsonArr = null; 
      jParser = new JsonParser(); 
      json = jParser.getJSONFromUrl(AppConstant.JSON_URL+urlPageIndex); 
      try { 
       dataJsonArr = json.getJSONArray(AppConstant.JSON_ARRAY_NAME); 
      } catch (JSONException e) { 
       // TODO Auto-generated catch block 
       e.printStackTrace(); 
      } 
      galleryAttributes = new ArrayList<HashMap<String, String>>(); 
      galleryAttributes.ensureCapacity(dataJsonArr.length()); 
      return null; 
     } 
    } 
} 

@SuppressLint("NewApi") public int getScreenWidth() { 
    int columnWidth; 
    WindowManager wm = (WindowManager) context.getSystemService(Context.WINDOW_SERVICE); 
    Display display = wm.getDefaultDisplay(); 

    final Point point = new Point(); 
    try { 
     display.getSize(point); 
    } catch (java.lang.NoSuchMethodError ignore) { 
     point.x = display.getWidth(); 
     point.y = display.getHeight(); 
    } 
    columnWidth = point.x; 
    return columnWidth; 
}

}

最后，我的适配器类：

public class GridViewImageAdapter extends BaseAdapter{ 
private Context context; 
private int imageWidth; 
private ArrayList<HashMap<String, String>> galleryAttributes; 
ImageView imageView; 

public GridViewImageAdapter(Context context, ArrayList<HashMap<String, String>> galleryAttributes, int imageWidth){ 
    this.galleryAttributes = galleryAttributes; 
    this.context = context; 
    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) { 

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

    Picasso.with(context).load(galleryAttributes.get(position).get("Link")).placeholder(R.drawable.loadingimage).into(imageView); 
    imageView.setScaleType(ImageView.ScaleType.CENTER_CROP); 
    imageView.setLayoutParams(new GridView.LayoutParams(imageWidth,imageWidth)); 
    return imageView; 
}

}

来源

2014-10-22 Kirby Aster Abadilla

你能请张贴GridView的XML？（）： – 2014-10-22 06:11:50

@HareshChhelana我张贴它上面，这是我的网格视图xml – 2014-10-22 06:13:01

我刚刚注意到这部分里面onLoadMoreItems（）： -galleryAttributes.addAll（generateData.execute（）。get（））; 我建议用： -generateData替换此部分。执行（）然后重写GenerateData的onPostExecute。把galleryAttributes.addAll（args）放在 – 2014-10-24 10:49:47

尝试在底部定位ProgressDialog这样的：

//In your asynctask 

ProgressDialog progressDialog; 

//In onPreExecute 

progressDialog = new ProgressDialog(context); 
progressDialog.setMessage("Fetching images"); 
progressDialog.setProgressStyle(ProgressDialog.STYLE_SPINNER); 
progressDialog.setIndeterminate(true); 
progressDialog.setCancelable(false); 
progressDialog.getWindow().setGravity(Gravity.BOTTOM); 
progressDialog.show(); 

//In onPostExecute 
progressDialog.dismiss();

希望它能帮助。

来源

2014-10-22 06:14:29

m_ctx里面，是否正确？对不起，因为我是Android编程新手 – 2014-10-22 06:16:37

是的。它的上下文@KirbyAsterAbadilla – 2014-10-22 06:17:05

谢谢，我会试试这个。 – 2014-10-22 06:19:13

试试这种方式，希望这会帮助你解决你的问题。

而不是采取只在您的布局采取垂直的LinearLayout作为父和GridView后放进度，GridView控件默认进度定的重量1到GridView.now走了，所以当你需要显示进度条就在你的代码和GONE可见当不再需要时。

activity_grid_view.xml

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" 
    android:layout_width="match_parent" 
    android:layout_height="match_parent" 
    android:orientation="vertical" 
    android:gravity="center"> 

    <GridView 
     android:id="@+id/grid_view" 
     android:layout_width="match_parent" 
     android:layout_height="0dp" 
     android:layout_weight="1" 
     android:numColumns="auto_fit" 
     android:gravity="center" 
     android:stretchMode="columnWidth" 
     android:background="#ffb4d9"> 
    </GridView> 

    <ProgressBar 
     android:id="@+id/progress_bar" 
     android:layout_width="wrap_content" 
     android:layout_height="wrap_content" 
     android:visibility="gone" /> 

</LinearLayout>

这里是代码如何为您的服务器响应，并更新数据，以您的活动实现接口。

WebServicesCallListener.java

public interface WebServicesCallListener { 
    public void onResponse(ArrayList<HashMap<String,String>> response); 
}

这里使用上述界面修改的Utils类

Utils.java

public class Utils { 

    private Context context; 

    public Utils(){} 

    public Utils(Context context){ 
     this.context = context; 
    } 

    public void getDataFromServer(final int urlPageIndex,final WebServicesCallListener listener){ 
     new AsyncTask<Void,Void,ArrayList<HashMap<String,String>>>(){ 
      @Override 
      protected ArrayList<HashMap<String, String>> doInBackground(Void... params) { 
       JsonParser jParser = new JsonParser(); 
       JSONObject json = jParser.getJSONFromUrl(AppConstant.JSON_URL + urlPageIndex); 
       JSONArray dataJsonArr; 
       try { 
        dataJsonArr = json.getJSONArray(AppConstant.JSON_ARRAY_NAME); 
       } catch (JSONException e) { 
        e.printStackTrace(); 
       } 
       ArrayList<HashMap<String, String>> galleryAttributes = new ArrayList<HashMap<String, String>>(); 
       galleryAttributes.ensureCapacity(dataJsonArr.length()); 
       for (int i = 0; i < dataJsonArr.length(); i++) { 
        JSONObject c = dataJsonArr.getJSONObject(i); 
        HashMap<String, String>() map = new HashMap<String, String>(); 
        map.put("Link", c.getString("Link")); 
        galleryAttributes.add(map); 
       } 
       return galleryAttributes; 
      } 

      @Override 
      protected void onPostExecute(ArrayList<HashMap<String, String>> data) { 
       super.onPostExecute(data); 
       listener.onResponse(data); 

      } 
     }.execute(); 
    } 
    @SuppressLint("NewApi") 
    public int getScreenWidth() { 
     int columnWidth; 
     WindowManager wm = (WindowManager) context.getSystemService(Context.WINDOW_SERVICE); 
     Display display = wm.getDefaultDisplay(); 

     final Point point = new Point(); 
     try { 
      display.getSize(point); 
     } catch (java.lang.NoSuchMethodError ignore) { 
      point.x = display.getWidth(); 
      point.y = display.getHeight(); 
     } 
     columnWidth = point.x; 
     return columnWidth; 
    } 
}

这里改变的Utils实施

GridViewActivity.java

public class GridViewActivity extends Activity implements AbsListView.OnScrollListener, AbsListView.OnItemClickListener{ 
    private GridView gridView; 
    private GridViewImageAdapter adapter; 
    private Utils utils; 
    private GenerateData generateData; 
    private ArrayList<HashMap<String, String>> galleryAttributes; 
    private int columnWidth; 
    private int urlPageIndex = 1; 
    private boolean hasRequestedMore; 

    @Override 
    protected void onCreate(Bundle savedInstanceState) { 
     super.onCreate(savedInstanceState); 
     setContentView(R.layout.activity_grid_view); 
     setTitle("Gallery"); 
     gridView = (GridView) findViewById(R.id.grid_view); 
     utils = new Utils(this); 
     InitializeGridLayout(); 

     galleryAttributes = new ArrayList<HashMap<String, String>>(); 

     utils.getDataFromServer(new WebServicesCallListener() { 
      @Override 
      public void onResponse(ArrayList<HashMap<String, String>> response) { 
       galleryAttributes.addAll(response); 
       adapter = new GridViewImageAdapter(GridViewActivity.this, galleryAttributes , columnWidth); 
       gridView.setAdapter(adapter); 
      } 
     }); 
     gridView.setOnScrollListener(this); 
     gridView.setOnItemClickListener(this); 

    } 

    public void InitializeGridLayout() { 
     Resources r = getResources(); 
     float padding = TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_DIP,AppConstant.GRID_PADDING, r.getDisplayMetrics()); 
     columnWidth = (int) ((utils.getScreenWidth() - ((AppConstant.NUM_OF_COLUMNS + 1) * padding))/AppConstant.NUM_OF_COLUMNS); 
     gridView.setNumColumns(AppConstant.NUM_OF_COLUMNS); 
     gridView.setColumnWidth(columnWidth); 
     gridView.setStretchMode(GridView.NO_STRETCH); 
     gridView.setPadding((int) padding, (int) padding, (int) padding,(int) padding); 
     gridView.setHorizontalSpacing((int) padding); 
     gridView.setVerticalSpacing((int) padding); 
    } 

    @Override 
    public void onItemClick(AdapterView<?> parent, View view, int position,long id) { 
     Intent intent = new Intent(GridViewActivity.this, CarouselViewActivity.class); 
     intent.putExtra("position", position); 
     intent.putExtra("galleryAttributes", galleryAttributes); 
     startActivity(intent); 
     Log.e("onItemClick: ", ""+position); 
    } 

    @Override 
    public void onScrollStateChanged(AbsListView view, int scrollState) { 
     Log.e("onScrollStateChanged: ", "" + scrollState); 
    } 

    @Override 
    public void onScroll(AbsListView view, int firstVisibleItem,int visibleItemCount, int totalItemCount) { 
     Log.e("onScroll: ", "firstVisibleItem:" + firstVisibleItem + " visibleItemCount:" + visibleItemCount + " totalItemCount:" + totalItemCount); 
     if(!hasRequestedMore){ 
      int lastInScreen = firstVisibleItem+visibleItemCount; 
      if(lastInScreen>=totalItemCount){ 
       hasRequestedMore = true; 
       onLoadMoreItems(); 
      } 
     } 
    } 

    public void onLoadMoreItems(){ 
     if(urlPageIndex<3){ 
      urlPageIndex++; 
      utils.getDataFromServer(urlPageIndex,new WebServicesCallListener() { 
       @Override 
       public void onResponse(ArrayList<HashMap<String, String>> response) { 
        galleryAttributes.addAll(response); 
        adapter.notifyDataSetChanged(); 
        hasRequestedMore = false; 
       } 
      }); 
     } 
    } 
}

来源

2014-10-22 06:18:30

感谢这个！我现在唯一需要做的是将进度条显示为可见并隐藏它的逻辑。 – 2014-10-22 06:39:55

@ KirbyAsterAbadilla，是的非常好赶上我认为这你很容易做到。 – 2014-10-22 06:42:35

是的，但我认为我需要改进我的工作，因为我认为从Web服务请求数据是导致onLoadMoreItems（）触发时我的活动滞后的原因，但它不是。 – 2014-10-22 07:05:03

如何在网格视图底部添加进度条页脚？

回答

相关问题