使用OnContextItemSelected从ListView项中检索文本 [英] Retrieving text from a ListView item with OnContextItemSelected

问题描述

我有一个带有经典上下文菜单的ListView，其中包含删除和类似选项。由于我要从SharedPreferences对象中删除，因此我需要检索键，它是设置到ListView项中的文本。

I've a ListView with a 'classic' context menu with delete and similar options. Since I'm deleting from a SharedPreferences object, I need to retrieve the key, which is the text set into ListView's items.

我尝试了以下代码：

    @Override
    public boolean onContextItemSelected(MenuItem item){
        AdapterContextMenuInfo saved = (AdapterContextMenuInfo) item.getMenuInfo();

        TextView view = (TextView)findViewById((int) saved.id);

        Log.d("DEBUG:", "before key");
        String key = view.getText().toString();
        Log.d("DEBUG:", "after...");

        switch (item.getItemId()){
            case R.id.conmenu_delete:
                return true;

            case R.id.conmenu_copy:
                return true;

            case R.id.conmenu_send:
                return true;

            default:
                return super.onContextItemSelected(item);
        }
    }

但是，不幸的是，在尝试检索

But, unfortunately, it crashes while trying to retrieve the text from the View, as I know from logs.

推荐答案

您已经正确投射了 AdapterContextMenuInfo 。

从那里，您可以获取targetView，然后可以将其再次投射到小部件中。我猜这是一个 TextView 。在该 TextView 上，您可以调用简单的 getText（）方法。

You have already correctly casted the AdapterContextMenuInfo.
From there, you can get the targetView which you can cast again into the widget. I guess it's a TextView in your case. On that TextView you can call the simple getText() method.

@Override
public boolean onContextItemSelected(MenuItem item) {

           AdapterContextMenuInfo info = (AdapterContextMenuInfo) item.getMenuInfo();
           String key = ((TextView) info.targetView).getText().toString();

           switch (item.getItemId()){
                case R.id.conmenu_delete:
                    return true;

                case R.id.conmenu_copy:
                    return true;

                case R.id.conmenu_send:
                    return true;

                default:
                    return super.onContextItemSelected(item);
          }
}

如果您的列表中填充了自定义对象，必须将其转换为相应的类型，例如：

If your list is populated with custom objects, you obviously have to cast it to the respective type, for example:

Person person = (Person) getListAdapter().getItem(info.position);
String key = person.getName();

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