Android自定义 ListView

Question

大家好我正在处理为员工显示任务的项目，这些任务需要由员工设置任务状态我通过菜单处理这个以更新统计信息这是数组适配器

public class MyArrayAdapter extends ArrayAdapter<Task> {
private static int viewCount = 0;

public MyArrayAdapter(Context context) {
    super(context, R.layout.listview_items, R.id.taskTitle);
}

@Override
public View getView(int position, View convertView, ViewGroup parent) {
    boolean created = false;
    if (convertView == null) {

        created = true;
        viewCount++;
    }

    View view = super.getView(position, convertView, parent);

    Task task = getItem(position);
    if (task != null) {
        TextView taskTitle = (TextView) view.findViewById(R.id.taskTitle);
        ImageView imageView = (ImageView) view.findViewById(R.id.taskImage);
        TextView taskStatus = (TextView) view.findViewById(R.id.taskStatus);
        TextView taskDate = (TextView) view.findViewById(R.id.taskDate);


        if (created && taskTitle != null) {
            taskTitle.setText(task.getTaskTitle());
        }
        if (imageView != null && task.image != null) {
            imageView.setImageDrawable(task.image);
        }
        if (taskStatus != null && task.taskStatus != null) {
            taskStatus.setText(task.getTaskStatus());
        }
        if (taskDate != null && task.taskDate != null) {
            taskDate.setText(task.getTaskDate());
        }
    }
    return view;
}

我需要更改 TextView “taskStatus”，我尝试这样做

        View v = adapter
            .getView(listView.getSelectedItemPosition(),null , null);
    TextView textView = (TextView) v.findViewById(R.id.taskStatus);
    textView.setText("Started");
    adapter.notifyDataSetChanged();

但是它不起作用任何人都可以帮助我

Answer 1

您应该从代码中删除以下行:

View v = adapter.getView(listView.getSelectedItemPosition(),null , null);
TextView textView = (TextView) v.findViewById(R.id.taskStatus);
textView.setText("Started");

并改为确定选定的 Task 实例:task，和

task.setTaskStatus("Started");
adapter.notifyDataSetChanged();

通过这种方式，您可以更改基础数据，并让适配器显示正确的 View (正确更新适当的 TextView，通过将此更改通知它；这就是 notifyDataSetChanged 方法。