BaseAdapter和ContextMenu

Question

你好，堆栈溢出社区，

基本上，我有一个图库，用gridView + imageView显示一些图像

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="fill_parent" android:layout_height="fill_parent">

    <GridView android:id="@+id/PhoneImageGrid"
            android:layout_width="fill_parent" android:layout_height="fill_parent"
            android:numColumns="auto_fit" android:verticalSpacing="12dp"
            android:horizontalSpacing="12dp" android:columnWidth="90dp"
            android:stretchMode="columnWidth" android:gravity="center" />

        <ImageView android:id="@+id/thumbImage" android:layout_width="wrap_content"
            android:layout_height="wrap_content" android:layout_centerInParent="true" 

            android:scaleType="centerCrop"
            />

​

我想对适配器显示的每个imageView使用setOnLongClick。但是，当单击imageView上的long时，我希望显示一个带有某些项的ContextMenu (例如，长时间单击imageView，显示带有一些项的contextMenu :图像信息，发送此图像.)。不幸的是，我不知道如何在适配器中充气这个菜单(可能不是一个好方法)。

在我的主要活动中有以下几行

_adapter = new ImageAdapter(activity,storedObjects.getAlbums());
imagegrid.setAdapter(_adapter);

我的适配器(删除了一些无用的行)

  public class ImageAdapter extends BaseAdapter {

    private Albums albums;
    private Context context;
    private LayoutInflater inflater;     



    public ImageAdapter(Context context, Albums albums) {

        this.albums = albums;
        this.context = context;
        inflater = (LayoutInflater)context.getSystemService (Context.LAYOUT_INFLATER_SERVICE);
        if(albums.getAlbumsListSize() == 0) {
            Toast.makeText(context, "There is no album to display", Toast.LENGTH_LONG).show();
        }
    }




    public View getView(final int position, View view, ViewGroup parent) {

        ViewHolder holder;

        if (view == null) {       
            holder = new ViewHolder();       
            view = inflater.inflate(R.layout.galleryitem, null);       
            holder.imageview = (ImageView) view.findViewById(R.id.thumbImage);        
            holder.checkbox = (CheckBox) view.findViewById(R.id.itemCheckBox); 
            holder.textview = (TextView) view.findViewById(R.id.album_name); 
            holder.checkbox.setChecked(true);
            //Bitmap loadingBM = BitmapFactory.decodeResource(context.getResources(),R.drawable.loading_image);
            //holder.imageview.setImageBitmap(loadingBM);
            view.setTag(holder);
        }

        else {
            holder = (ViewHolder) view.getTag();
        }

        holder.imageview.setClickable(true);


        holder.imageview.setOnLongClickListener(new OnLongClickListener() {


            public boolean onLongClick(View v) {

                Log.v(TAG,"onLongClick ok !");
                return false;
            }

        });


        imageDownloader.download(this.context, albums.getAllAlbums().get(position).getThumbnailUri(), holder.imageview);            


        return view;
    }

问题：

1. setOnLongClickListener工作正常，当我单击图像时，日志显示在logcat中，但是，如何为每个imageView ?

创建一个菜单

显然，我只能在我的主要活动中重写onCreateContextMenu。我想我可以把每个ImageView传递给onCreateContextMenu(ContextMenu菜单，View，ContextMenuInfo menuInfo)，但是如何传递呢？

如果你能帮我解决这个问题，我会非常感激的。

非常感谢

弗洛伦特·瓦尔德列夫

Answer 1

与其在setOnLongClickListener上使用ImageView，不如用GridView调用registerForContextMenu。然后，实现onCreateContextMenu和onContextItemSelected。

下面是一个简单的ListActivity，向您展示它是如何工作的。

public class GreetingActivity extends ListActivity {
  private static final String[] mGreetings = { "Hello", "Goodbye" };
  private static final String[] mPeople = { "Alice", "Bob", "Charlie" };

  @Override
  public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);

    ArrayAdapter<String> adapter = new ArrayAdapter<String>(this,
        android.R.layout.simple_list_item_1, mPeople);
    setListAdapter(adapter);
    ListView listView = getListView();
    registerForContextMenu(listView);
  }

  @Override
  public void onCreateContextMenu(ContextMenu menu, View v,
      ContextMenu.ContextMenuInfo menuInfo) {
    for (int i = 0; i < mGreetings.length; ++i) {
      String greeting = mGreetings[i];
      menu.add(v.getId(), i, ContextMenu.NONE, "Say " + greeting);
    }
  }

  @Override
  public boolean onContextItemSelected(MenuItem item) {
    AdapterView.AdapterContextMenuInfo menuInfo
        = (AdapterView.AdapterContextMenuInfo) item.getMenuInfo();
    int adapterPosition = menuInfo.position;
    String person = mPeople[adapterPosition];

    int menuItemId = item.getItemId();
    String greeting = mGreetings[menuItemId];

    String msg = String.format("%s, %s!", greeting, person);
    Toast.makeText(this, msg, Toast.LENGTH_SHORT).show();

    return true;
  }
}

Answer 2

非常感谢@chiuki，它的工作原理与预期一样

public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
    ...
final GridView imagegrid = (GridView) findViewById(R.id.PhoneImageGrid);                                        
registerForContextMenu(imagegrid);  
storedObjects.storeThumbnailsURI();     
_adapter = new ImageAdapter(activity,storedObjects.getAlbums());
imagegrid.setAdapter(_adapter); 
}


@Override
public void onCreateContextMenu(ContextMenu menu, View v,ContextMenuInfo menuInfo) {  
      AdapterContextMenuInfo info = (AdapterContextMenuInfo) menuInfo;
    Log.v("context menu","context menu");
    menu.setHeaderTitle("Context Menu");  
    menu.add(0, START_SLIDESHOW_ON_THIS_ALBUM, 0, "Start SlideShow for this Album");  
    menu.add(0, DOWNLOAD_WHOLE_ALBUM, 0, "Download this Album");  

}   

@Override
public boolean onContextItemSelected(MenuItem item) {
    AdapterContextMenuInfo info = (AdapterContextMenuInfo) item.getMenuInfo();
    switch (item.getItemId()) {

    case START_SLIDESHOW_ON_THIS_ALBUM:
        selectThisAlbumOnly(info);
        startSlideShow();   
    break;
    case DOWNLOAD_WHOLE_ALBUM:

    break;        
    }
    return true;
}   

在适配器中，确保没有任何setClickable = true

干杯

弗洛伦特