Question

在我的应用程序中，我想更改用户单击的列表视图中的imageview。开始我通过适配器类传递列表视图中的图像，但点击项目我想更改图像视图中的图像在listview中，我如何在特定位置更改图像。??

MainActivity

public class MainActivity extends Activity {
     ListView listView;
 public static int pos = 0;
    String[] Prayers = new String[] { "REFLETINDO A IMAGEM DE CRISTO",
            "PROVIDÊNCIA PARA TODOS OS CASOS", "A CRUZ REVELA O AMOR DE DEUS",
            "REFLETINDO O AMOR DE CRISTO", "CRISTO CRUCIFICADO POR NÓS",
            "AMOR IMENSURÁVEL", "DÁDIVA DO AMOR DE DEUS",
            "NÃO PARA CONDENAR, MAS PARA SALVAR",
            "O CENTRO DE MINHA ESPERANÇA",


    };

    String[] Dias = new String[] { "Dia1", "Dia2", "Dia3", "Dia4", "Dia5",
            "Dia6", "Dia7", "Dia8", "Dia9", "Dia10", "Dia11", "Dia12",
            "Dia13", "Dia14", "Dia15", "Dia16", "Dia17", "Dia18",


    };
    LinearLayout lay1 ,lay2;
    int i=0;
    int img ;

    List<RowItem> rowItems;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.fragment_main);

       img = R.drawable.praying_hands_normal ;


       rowItems = new ArrayList<RowItem>();
       for (int i = 0; i < 50; i++) {
           RowItem item = new RowItem( Dias[i], Prayers[i],img);
           rowItems.add(item);
       }

       listView = (ListView) findViewById(R.id.listview);
       BaseClass adapter = new BaseClass(this, rowItems);
       listView.setAdapter(adapter);
       //listView.setOnItemClickListener(this);

            // get the position of the clicked item 
        View t = null;
            listView.setOnItemClickListener(new AdapterView.OnItemClickListener() {

                @Override
                public void onItemClick(AdapterView<?> parent, View view,
                        int position, long id) {
                    // TODO Auto-generated method stub

                    pos = position;
                    //Toast.makeText(getApplication(), String.valueOf(pos), Toast.LENGTH_LONG).show();
                    Intent i = new Intent(MainActivity.this ,OpenActivity.class);
                    startActivity(i);

                }
            });

    }

Adapterclass

    public View getView(int position, View convertView, ViewGroup parent) {
                ViewHolder holder = null;

                LayoutInflater mInflater = (LayoutInflater) context
                        .getSystemService(Activity.LAYOUT_INFLATER_SERVICE);
                if (convertView == null) {
                    convertView = mInflater.inflate(R.layout.list, null);
                    holder = new ViewHolder();

                    holder.txtDias = (TextView) convertView.findViewById(R.id.dias);
                    holder.txtPrayers = (TextView) convertView
                            .findViewById(R.id.prayers);
                    holder.imageView = (ImageView) convertView
                            .findViewById(R.id.symbol);
                    convertView.setTag(holder);
                } else {
                    holder = (ViewHolder) convertView.getTag();
                }

                RowItem rowItem = (RowItem) getItem(position);

                holder.txtPrayers.setText(rowItem.getDesc());
                holder.txtDias.setText(rowItem.getTitle());
                holder.imageView.setImageResource(R.drawable.praying_hands_normal);
          if(pos == position && OpenActivity.a + OpenActivity.b +
                  OpenActivity.c == 1 || OpenActivity.a + OpenActivity.b +
                  OpenActivity.c == 2)
          {
              holder.imageView.setImageResource(R.drawable.praying_hands_bookmark);

          } 

          else if(pos == position && OpenActivity.a + OpenActivity.b +
                  OpenActivity.c == 3 )
          {
              holder.imageView.setImageResource(R.drawable.praying_hands_selected);
          }


        return convertView;

}

Answer 1

onItemClick（）方法中的参数具有“视图视图”，其中afaik是您按下的项目。 view.findViewById（）关注该行。

试试这个。

listView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
    @Override
    public void onItemClick(AdapterView<?> parent, View view, int position, long id) {

     // Add following to your listener
     ImageView image = (ImageView) view.findViewById( R.id.item_image );
     image.setBackground( getResources().getDrawable( R.drawable.new_item_image ));

     // Or
     Drawable img = ( Drawable ) getResources().getDrawable( R.drawable.new_item_image ));
     image.setBackground( img );

   }
});

编辑：在您从意图返回时保持项目更改，请尝试此

在MainActivity中，添加一个View，Context＆amp; ImageView的，

public class MainActivity extends Activity {
  public View row;
  public Context ctx;
  public ImageView newImage;

  // your code

在onItemClickListener中添加此内容，

  row = view; 
  ctx = getBaseContext();
  newImage = ( ImageView ) getResources().getDrawable( R.drawable.new_item_image ));

现在添加一个名为“setImage”的新方法（在MainActivity类中），

public void setImage( View row ) {
  ImageView item_image = ( ImageView ) row.findViewById( R.id.item_image );
  item_image.setBackground( newImage );
}

当您离开新活动时，请先调用它，

MainActivity.setImage( MainActivity.row );

告诉我这是否有效，我自己没试过。

Answer 2

回到Activity后，ListView刷新了，在这个时候，每个项目的getView（）都会执行，但你的RowItem仍然保留旧的ImageId，这就是为什么上一张图片看得见，只需在项目点击时修改RowItem的imageId：

@Override 
public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
    RowItem rowItem = rowItems.get(position);
    rowItem.setImageId(R.drawable.new_item_image);

    Intent i = new Intent(MainActivity.this ,OpenActivity.class);
    startActivity(i);
}

--------------- 3小时后更新---------------

将BaseClass保存在onCreate（）方法之外，通知onResume（）更改的数据集：

public class MainActivity extends Activity {

    private BaseClass adapter;

    protected void onCreate(Bundle savedInstanceState) {
        ...
        adapter = new BaseClass(this, rowItems);
        ...
    }

    @Override
    public void onResume() {
        super.onResume();
        adapter.notifyDataSetChanged();
    }

}

顺便说一下，你也应该发布BaseClass代码。

如何更改列表视图中单击项目的图像

2 个答案: