ListView數(shù)據(jù)更新實時顯示

要在ListView中實時更新數(shù)據(jù)并顯示，你可以使用以下方法：

1. 創(chuàng)建一個適配器類，繼承自BaseAdapter。

public class MyAdapter extends BaseAdapter {
    private Context context;
    private List<String> dataList;

    public MyAdapter(Context context, List<String> dataList) {
        this.context = context;
        this.dataList = dataList;
    }

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

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

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

    @Override
    public View getView(int position, View convertView, ViewGroup parent) {
        ViewHolder viewHolder;
        if (convertView == null) {
            convertView = LayoutInflater.from(context).inflate(R.layout.list_item, parent, false);
            viewHolder = new ViewHolder();
            viewHolder.textView = convertView.findViewById(R.id.text_view);
            convertView.setTag(viewHolder);
        } else {
            viewHolder = (ViewHolder) convertView.getTag();
        }
        viewHolder.textView.setText(dataList.get(position));
        return convertView;
    }

    static class ViewHolder {
        TextView textView;
    }
}

2. 在Activity中創(chuàng)建一個ListView和一個適配器實例。

public class MainActivity extends AppCompatActivity {
    private ListView listView;
    private MyAdapter adapter;
    private List<String> dataList;

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

        listView = findViewById(R.id.list_view);

        // 初始化數(shù)據(jù)列表
        dataList = new ArrayList<>();
        for (int i = 1; i <= 20; i++) {
            dataList.add("Item " + i);
        }

        // 創(chuàng)建適配器實例
        adapter = new MyAdapter(this, dataList);
        listView.setAdapter(adapter);
    }
}

3. 創(chuàng)建一個方法來更新數(shù)據(jù)列表并刷新適配器。

private void updateDataList(List<String> newDataList) {
    // 更新數(shù)據(jù)列表
    dataList.clear();
    dataList.addAll(newDataList);

    // 刷新適配器
    adapter.notifyDataSetChanged();
}

4. 在需要更新數(shù)據(jù)的地方調(diào)用updateDataList()方法。例如，你可以在接收到新數(shù)據(jù)時更新數(shù)據(jù)列表：

// 模擬接收到新數(shù)據(jù)
new Handler().postDelayed(() -> {
    List<String> newDataList = new ArrayList<>();
    for (int i = 21; i <= 30; i++) {
        newDataList.add("Item " + i);
    }
    updateDataList(newDataList);
}, 3000);

這樣，當(dāng)數(shù)據(jù)列表更新時，ListView將實時顯示新的數(shù)據(jù)。