Android 列表视图刷新

Question

我有一个 ListView，它通过一个数组向我显示一些数据（它在另一个类中，我通过它的对象访问它）。

每当我通过上下文菜单从 ListView 中删除一个元素时，列表不会刷新，但该元素会从数组中删除。如何刷新列表以显示此内容？

代码：

     public void onCreateContextMenu(ContextMenu menu, View v,
        ContextMenuInfo menuInfo) {
    if (v.getId()==R.id.mainListView) {
        AdapterView.AdapterContextMenuInfo info = (AdapterView.AdapterContextMenuInfo)menuInfo;
        post=info.position;
      menu.setHeaderTitle(stocks[info.position]);
        String[] menuItems = stt;
        for (int i = 0; i<menuItems.length; i++) {
            menu.add(Menu.NONE, i, i, menuItems[i]);
            }
    }
  }

     @Override
      public boolean onContextItemSelected(MenuItem item) {
        AdapterView.AdapterContextMenuInfo info = (AdapterView.AdapterContextMenuInfo)item.getMenuInfo();
        int menuItemIndex = item.getItemId();
        String[] menuItems = stt;
        String menuItemName = menuItems[menuItemIndex];
        listItemName = stocks[info.position];
        stockname.remove(post-1);

    return true;
  }

Answer 1

我没有notifyDataSetChanged() 方法（Android 2.3）。

以下对我有用：

getListView().invalidate();

就我而言，我已经更改了整个适配器，但它仍然没有刷新，所以对我来说，上述方法是唯一可行的解​​决方案。

Answer 2

为我刷新列表：listView.invalidateViews();

会做的：

mDataChanged = true;
rememberSyncState();
requestLayout();
invalidate();

管理某些列表项删除或一次删除所有元素的情况。

在 API 24 中测试。

Answer 3

    private static ArrayList<Radio> m_streamsList;

    final ListView listView = (ListView) rootView.findViewById(R.id.stream_listRS);

    //my class where i insert data into my array
    m_myDBHelp = new DBHelper();
    m_streamsList = m_myDBHelp.selectStreamsList();

    // my list adapter - this is a class created by me
    RadioAdapter adapt = new RadioAdapter(context, m_streamsList);
    listView.setAdapter(adapt);

    ////////////------------- so . when i inserted a row in db, i need to refresh the list
    m_myDBHelp.insertStreamIntoDB(String name, String url);
    /// in my case method invalidate works fine
    listView.invalidate();
    m_streamsList = null;
    m_streamsList = m_myDBHelp.selectStreamsList();

    //you need to set adapter again
    RadioAdapter adapt2 = new RadioAdapter(context, m_streamsList);
    listView.setAdapter(adapt2);






import android.content.Context;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseAdapter;
import android.widget.ImageView;
import android.widget.LinearLayout;
import android.widget.TextView;

import com.example.npopa.musicplayern.R;
import com.example.npopa.musicplayern.Radio;

import java.util.ArrayList;

public class RadioAdapter extends BaseAdapter{
private ArrayList<Radio> m_streams;
private LayoutInflater m_stramInf;

public RadioAdapter(Context c, ArrayList<Radio> theStreams){
    m_streams = theStreams;
    m_stramInf = LayoutInflater.from(c);
}

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

@Override
public Object getItem(int arg0) {
    return null;
}

@Override
public long getItemId(int arg0) {
    return 0;
}

@Override
public View getView(int position, View convertView, ViewGroup parent) {
    //map to radio_s layout
    LinearLayout streamLay = (LinearLayout) m_stramInf.inflate(R.layout.all_songs_t, parent, false);

    TextView name = (TextView) streamLay.findViewById(R.id.song_title);
    TextView url = (TextView) streamLay.findViewById(R.id.song_artist);
    ImageView imgALb = (ImageView) streamLay.findViewById(R.id.albumicon);

    //get all_songs_t using position
    Radio currStream = m_streams.get(position);
    name.setText(currStream.getName());
    url.setText(currStream.getUrl());
    imgALb.setImageResource(R.drawable.radio_stream);

    //set position as tag
    streamLay.setTag(position);
    return streamLay;
}

}

public class Radio {
private int id;
private String name;
private String url;

public Radio(int id, String name, String url) {
    this.id = id;
    this.name = name;
    this.url = url;
}

public int getId() {
    return id;
}

public void setId(int id) {
    this.id = id;
}

public String getName() {
    return name;
}

public void setName(String name) {
    this.name = name;
}

public String getUrl() {
    return url;
}

public void setUrl(String url) {
    this.url = url;
}
}

Answer 4

您必须通知您的 ListView 适配器数据已更改。

listViewAdapater.notifyDataSetChanged();

如果由于某种原因这不起作用并且在某些奇怪的情况下它似乎没有通知，您可以通过构造函数使用更新后的数组重新分配您的适配器。

Answer 5

试试 getListView().refreshDrawableState