如何在适配器中更改imageview的图片？

Question

我解决了这个问题。您可以使用Handler将消息发送到您的Fragment，然后在您的片段中使用adapter.notifyDataSetChanged（）。

我想在单击时更改ImageView的图片，这些组件都在适配器中，并且我也使用adapter.notifyDataSetChanged（）;该适配器在Fragment中使用并将其放入GridView中，我发现了一些文章表示使用adapter.notifyDataSetChanged（）可以告诉程序更新其UI。 但是对我来说这是行不通的，我该怎么办？ 先感谢您。 这是我的代码和xml：

public class ResItemAdapter extends BaseAdapter{
private ViewHolder holder;
private LayoutInflater inflater;
private Context context;
private List<ResBean> lists;
private ResBean bean;
private int appType;
private DBUtil db;
private ResItemAdapter adapter;

public ResItemAdapter(Context con)
{
    this.context=con;
    inflater=(LayoutInflater)context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
    this.adapter=this;
}
public ResItemAdapter(Context con,List<ResBean> lists)
{
    this.lists = lists;
    this.context=con;
    inflater=(LayoutInflater)context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
    this.adapter=this;
}
public ResItemAdapter(Context con,List<ResBean> lists,int appType,DBUtil db)
{
    this.context=con;
    this.lists=lists;
    this.db=db;
    this.appType=appType;
    inflater=(LayoutInflater)context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
    this.adapter=this;
}

@Override
public int getCount()
{
    return lists.size();
}

@Override
public Object getItem(int position)
{
    return position;
}

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

@Override
public View getView(final int position, View convertView, ViewGroup parent)
{
    if(convertView==null)
    {
        holder=new ViewHolder();
        convertView=inflater.inflate(R.layout.res_item,null);
        convertView.setLayoutParams(new GridView.LayoutParams(LayoutParams.WRAP_CONTENT,150));
        holder.resLayout = (RelativeLayout)convertView.findViewById(R.id.res_item_select_s);
        holder.resItemImage=(ImageView)convertView.findViewById(R.id.res_item_image_s);
        holder.resItemName=(TextView)convertView.findViewById(R.id.res_item_name_s);
        holder.resItemDingyue=(TextView)convertView.findViewById(R.id.res_item_dingyue_s);
        holder.resItemStar=(ImageView)convertView.findViewById(R.id.res_item_star_s);
        holder.resItemSelectedBtn=(ImageView)convertView.findViewById(R.id.res_item_selected_btn_s);
        convertView.setTag(holder);
    }else{
        holder=(ViewHolder)convertView.getTag();
    }
    bean=lists.get(position);
    String imagePath = FileUtils.getItemImagePath(lists.get(position).getPath());
    if(imagePath.equals("")){
        holder.resItemImage.setBackgroundResource(R.drawable.moren);
    }else{
        try {
            holder.resItemImage.setImageBitmap(BitmapFactory.decodeFile(FileUtils.getItemImagePath(lists.get(position).getPath())));
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
    holder.resItemName.setText(bean.getName());
    holder.resItemDingyue.setText(bean.getBookCount()+"人订阅");
    setStar(bean);
    if(bean.isBook())
    {
        holder.resItemSelectedBtn.setImageDrawable(context.getResources().getDrawable(R.drawable.but_icon_subscribed));
    }else{          
        holder.resItemSelectedBtn.setImageDrawable(context.getResources().getDrawable(R.drawable.content_add_btn_empty));
    }
    holder.resLayout.setOnClickListener(new OnClickListener() {

        @Override
        public void onClick(View v)
        {
            PopWindow mPop = new PopWindow(context,lists.get(position));
            mPop.setResDetailPop(holder.resLayout);
        }
    });
    holder.resItemSelectedBtn.setOnClickListener(new OnClickListener()
    {
        @Override
        public void onClick(View v)
        {
            bean=lists.get(position);
            if(db.insertBookOrder(bean,appType))
            {
                Log.d("test","resId="+bean.getId()+"  position="+position);
                holder.resItemSelectedBtn.setImageDrawable(context.getResources().getDrawable(R.drawable.but_icon_subscribed));
                adapter.notifyDataSetChanged();
            }
        }
    });
    return convertView;
}
private void setStar(ResBean bean)
{
    int stars=bean.getRating();
    switch(stars)
    {
    case 0:
        holder.resItemStar.setBackgroundResource(R.drawable.small_star0);
        break;
    case 1:
        holder.resItemStar.setBackgroundResource(R.drawable.small_star1);
        break;
    case 2:
        holder.resItemStar.setBackgroundResource(R.drawable.small_star2);
        break;
    case 3:
        holder.resItemStar.setBackgroundResource(R.drawable.small_star3);
        break;
    case 4:
        holder.resItemStar.setBackgroundResource(R.drawable.small_star4);
        break;
    case 5:
        holder.resItemStar.setBackgroundResource(R.drawable.small_star5);
        break;
    }
}

class BitmapTask extends AsyncTask<Integer,Void,Bitmap>
{
    private final WeakReference<ImageView> reference;
    private String path;

    public BitmapTask(ImageView imageView,String path)
    {
        reference=new WeakReference<ImageView>(imageView);
        this.path=path;
    }
    @Override
    protected Bitmap doInBackground(Integer... arg0)
    {
        try {
            return BitmapFactory.decodeStream(new FileInputStream(FileUtils.getImagePath(path)));
        } catch (FileNotFoundException e) {
            e.printStackTrace();
        }
        return null;
    }
    @Override
    protected void onPostExecute(Bitmap bitmap)
    {
        if(reference!=null&& bitmap!=null)
        {
            final ImageView view=reference.get();
            if(view!=null)
            {
                view.setImageBitmap(bitmap);
            }
        }
    }
}
class ViewHolder
{
    public RelativeLayout resLayout;
    public ImageView resItemImage;
    public ImageView resItemStar;
    public TextView resItemName;
    public TextView resItemDingyue;
    public ImageView resItemSelectedBtn;
}}

XML：

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:id="@+id/res_item_select_s"
android:layout_width="match_parent"
android:layout_height="fill_parent"
android:background="@color/background_default" >

<RelativeLayout
    android:layout_width="match_parent"
    android:layout_height="fill_parent"
    android:layout_marginBottom="50dip"
    android:layout_marginTop="12dip" >

    <ImageView
        android:id="@+id/res_item_image_s"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentLeft="true"
        android:layout_marginLeft="10dip"
        android:layout_marginTop="5dip"
        android:contentDescription="@string/description"/>

    <RelativeLayout
        android:id="@+id/res_item_content_s"
        android:layout_width="200dip"
        android:layout_height="wrap_content"
        android:layout_alignBottom="@id/res_item_image_s"
        android:layout_marginLeft="8dip"
        android:layout_marginTop="5dip"
        android:layout_toRightOf="@id/res_item_image_s"
        android:orientation="vertical" >

        <TextView
            android:id="@+id/res_item_name_s"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_alignParentTop="true"
            android:textSize="20sp" />

        <ImageView
            android:id="@+id/res_item_star_s"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_below="@id/res_item_name_s"
            android:layout_centerVertical="true"
            android:contentDescription="@string/description" />

        <TextView
            android:id="@+id/res_item_dingyue_s"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_alignParentBottom="true"
            android:layout_marginTop="5dip"
            android:textSize="12sp" />
    </RelativeLayout>

    <ImageView
        android:id="@+id/res_item_selected_btn_s"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentRight="true"
        android:layout_alignParentTop="true"
        android:background="#00000000"
        android:contentDescription="@string/description"/>
</RelativeLayout>

Answer 1

为什么不尝试选择器呢？我认为您可以通过将abc.xml放置在drawable文件夹中来实现，您可以在单击item之前和之后提供图像。 然后在程序中使用R.drawable.abc

abc.xml
    <?xml version="1.0" encoding="utf-8"?>
    <selector xmlns:android="http://schemas.android.com/apk/res/android" >

      <item android:drawable="@drawable/selectedimage" android:state_pressed="true"
              android:state_selected="true" />
        <item android:drawable="@drawable/unselected" />
    </selector>

Answer 2

我解决了这个问题。您可以使用Handler将消息发送到您的Fragment，然后在您的片段中使用adapter.notifyDataSetChanged（）。

任何人都可以告诉我，为什么要在片段中放入adapter.notifyDataSetChanged（）？我在活动中使用的适配器中使用的最后一个APP可以。