我如何获得notifyDatasetChanged（）与一个ListAdapter工作？ [英] How do I get notifyDatasetChanged() to work with a ListAdapter?

问题描述

现在我用setAdapter更新我的ListView，但我认为正确的方法是使用notifiyDatasetChanged（），我不能得到这在我的主要工作类（它在适配器）。以下是错误：

该方法notifyDatasetChanged（）是未定义的类型ListAdapter

我猜有这样做的更好的办法？ - 任何人都可以点我在正确的方向

下面是我的code的相关部分：

 公共类ScoreList扩展SherlockFragmentActivity {    私人的ListView listViewScore;    静态列表＆LT;分值GT; listScore =新的ArrayList＆LT;分值GT;（）;
    @覆盖
    公共无效的onCreate（捆绑savedInstanceState）{        super.onCreate（savedInstanceState）;
        的setContentView（R.layout.score_list）;
        CTX =这一点;
        listScore = dbh.getAllScores（）;        listViewScore =（ListView控件）findViewById（R.id.score_list）;        listViewScore.setAdapter（新ScoreListAdapter（CTX，
                R.layout.score_row_item，listScore））;
        listViewScore.getAdapter（）notifyDatasetChanged（）。 //这是我得到的错误
    }
}
 

这里的适配器：

 公共类ScoreListAdapter扩展ArrayAdapter＆LT;分值GT; {
    私人诠释的资源;
    私人LayoutInflater吹气;    公共ScoreListAdapter（上下文CTX，INT RESOURCEID，列表与LT;分数＆GT;对象）{
        超（CTX，RESOURCEID，对象）;
        资源= RESOURCEID;
        吹气= LayoutInflater.from（CTX）;
        //语境= CTX;
    }    @覆盖
    公共查看getView（最终诠释的立场，观点convertView，父母的ViewGroup）{        convertView =（的LinearLayout）inflater.inflate（资源，NULL）;        分数分数=的getItem（位置）;        TextView的txtName的=（TextView中）convertView.findViewById（R.id.name）;
        txtName.setText（score.getName（））;        TextView的txtScoreChange =（TextView中）convertView
                .findViewById（R.id.scoreChange）;
        INT scoreChange =的Integer.parseInt（score.getScoreChange（））;
        如果（scoreChange大于0）
            txtScoreChange.setText（++ scoreChange）;
        否则如果（scoreChange℃，）
            txtScoreChange.setText（+ scoreChange）;
        其他
            txtScoreChange.setText（）;        TextView的txtScoreTotal =（TextView中）convertView
                .findViewById（R.id.scoreTotal）;
        txtScoreTotal.setText（score.getScoreTotal（））;        最终的LinearLayout currentRow =（LinearLayout中）convertView
                .findViewById（R.id.scoreRowLayout）;        notifyDataSetChanged（）;
        返回convertView;
    }
}
 

解决方案

创建自定义适配器的一个实例，因此你可以在任何地方使用它，你喜欢...

 公共类ScoreList扩展SherlockFragmentActivity {私人的ListView listViewScore;私人ScoreListAdapter适配器;静态列表＆LT;分值GT; listScore =新的ArrayList＆LT;分值GT;（）;
@覆盖
公共无效的onCreate（捆绑savedInstanceState）{    super.onCreate（savedInstanceState）;
    的setContentView（R.layout.score_list）;
    CTX =这一点;
    listScore = dbh.getAllScores（）;    listViewScore =（ListView控件）findViewById（R.id.score_list）;    适配器=新ScoreListAdapter（CTX，R.layout.score_row_item，listScore）;
    listViewScore.setAdapter（适配器）;
    adapter.notifyDatasetChanged（）;
}
}
 

顺便说一句，如果你的listScore阵列已经被加载，那么你就需要使用

  adapter.notifyDatasetChanged（）;
 

Right now I use setAdapter to update my ListView, but I think the proper way is to use notifiyDatasetChanged() and I can't get that to work in my main class (it's in the adapter). Here is the error:

The method notifyDatasetChanged() is undefined for the type ListAdapter

I'm guessing there is a better way of doing this - can anyone point me in the right direction?

Here's the relevant parts of my code:

public class ScoreList extends SherlockFragmentActivity {

    private ListView listViewScore;

    static List<Score> listScore = new ArrayList<Score>();
    @Override
    public void onCreate(Bundle savedInstanceState) {

        super.onCreate(savedInstanceState);
        setContentView(R.layout.score_list);
        ctx = this;
        listScore = dbh.getAllScores();

        listViewScore = (ListView) findViewById(R.id.score_list);

        listViewScore.setAdapter(new ScoreListAdapter(ctx,
                R.layout.score_row_item, listScore));
        listViewScore.getAdapter().notifyDatasetChanged(); //this is where I get the error
    }
}

Here's the adapter:

public class ScoreListAdapter extends ArrayAdapter<Score> {
    private int resource;
    private LayoutInflater inflater;

    public ScoreListAdapter(Context ctx, int resourceId, List<Score> objects) {
        super(ctx, resourceId, objects);
        resource = resourceId;
        inflater = LayoutInflater.from(ctx);
        //context = ctx;
    }

    @Override
    public View getView(final int position, View convertView, ViewGroup parent) {

        convertView = (LinearLayout) inflater.inflate(resource, null);

        Score score = getItem(position);

        TextView txtName = (TextView) convertView.findViewById(R.id.name);
        txtName.setText(score.getName());

        TextView txtScoreChange = (TextView) convertView
                .findViewById(R.id.scoreChange);
        int scoreChange = Integer.parseInt(score.getScoreChange());
        if (scoreChange > 0)
            txtScoreChange.setText("+" + scoreChange);
        else if (scoreChange < 0)
            txtScoreChange.setText("" + scoreChange);
        else
            txtScoreChange.setText("");

        TextView txtScoreTotal = (TextView) convertView
                .findViewById(R.id.scoreTotal);
        txtScoreTotal.setText(score.getScoreTotal());

        final LinearLayout currentRow = (LinearLayout) convertView
                .findViewById(R.id.scoreRowLayout);                 

        notifyDataSetChanged();
        return convertView;
    }   
}

解决方案

Create an instance of your custom adapter, so you can use it anywhere you like...

public class ScoreList extends SherlockFragmentActivity {

private ListView listViewScore;

private ScoreListAdapter adapter;

static List<Score> listScore = new ArrayList<Score>();
@Override
public void onCreate(Bundle savedInstanceState) {

    super.onCreate(savedInstanceState);
    setContentView(R.layout.score_list);
    ctx = this;
    listScore = dbh.getAllScores();

    listViewScore = (ListView) findViewById(R.id.score_list);

    adapter = new ScoreListAdapter(ctx, R.layout.score_row_item, listScore);
    listViewScore.setAdapter(adapter);
    adapter.notifyDatasetChanged(); 
}
}

By the way, if your listScore array is already loaded, then you do not need to use

adapter.notifyDatasetChanged(); 

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