覆盖ArrayAdapter的getView以填充3个Textviews [英] Overriding getView of ArrayAdapter to fill 3 Textviews

问题描述

在我的活动中，我正在调用扩展了 AsyncTask 的 MovieTask .我从服务器获取了Json响应，该响应已在 MovieTask 的 doInBackground 方法内成功解析.

From my Activity, I am calling my MovieTask that extendsAsyncTask. I get Json response from the server which I have successfully parsed inside the doInBackground method of MovieTask.

现在，我在活动中有一个列表视图，我想使用扩展了 ArrayAdapter 的 MovieListAdapter 填充列表视图.

Now, I have a listview in my activity and I want to populate the listview using MovieListAdapter that extends ArrayAdapter.

对于每个视图(即一行)，我要填充3个 TextView .我覆盖了 MovieListAdapter 的 getView 方法以填充相同内容.但是我不明白如何将数据从我的活动发送到 getView 方法到 getView 方法以填充文本视图?

For every view (i.e. a row), I want to fill 3 TextViews. I am overriding getView method of MovieListAdapter to fill the same. But I don't understand how to send the data to getView method from my activity to getView method to populate the textviews?

public class MovieTask extends AsyncTask<String, Void, String>{        

    @Override
    protected String  doInBackground(String... urls) {
        //I HAVE GOT THE JSON DATA THAT CONTAINS AN ARRAY..
        //EACH ENTRY IN ARRAY SHOULD BE FILLED IN A SINGLE ROW IN LISTVIEW

        getMovieDataFromJson(result);
    }

    private void getMovieDataFromJson(String JsonString) throws JSONException {

        JSONObject jsonObject = new JSONObject(JsonString);
        JSONArray results = jsonObject.getJSONArray("results");

        for (int i=0; i<results.length(); i++){
            String title = results.getJSONObject(i).getString("original_title");
            String date = results.getJSONObject(i).getString("release_date");
            long id = results.getJSONObject(i).getLong("id");
            double vote = results.getJSONObject(i).getDouble("vote_average");


             //HERE I NEED TO CALL THE GETVIEW METHOD SO THAT IT FILLS THE ROW OF THE LISTVIEW WITH THESE VALUES - title, date and vote
        }
}

MovieListAdapter.java

MovieListAdapter.java

    public class MovieListAdapter extends ArrayAdapter<String > {
    public MovieListAdapter(Context context, int resource, int textViewResourceId, List<String> objects) {
        super(context, resource, textViewResourceId, objects);
    }

    @Override
    public View getView(int position, View convertView, ViewGroup parent) {
       // I NEED TO PREPARE EACH ROW OF LISTVIEW HERE
       //EVERY ROW CONTAINS 3 TEXTVIEWS WHICH I NEED TO FILL
       //BUT HOW DO I SEND DATA TO FILL THE TEXTVIEW ?
     }

}

推荐答案

当您在 AdapterView 上 setAdapter()时，例如 ListView ，在内部调用 getView()，从同一视图返回的视图将填充在 AdapterView 中.

When you setAdapter() on an AdapterView for example ListView, getView() is called internally and the views returned from the same are populated in the AdapterView.

您可能想阅读并了解 AdapterView 和 Adapter 的工作方式.继续阅读这里的一些文档:

You might want to read and learn about how AdapterViews and Adapters work. Go ahead and read some docs here:

• 将ArrayAdapter与ListView一起使用
• 用于ListView的自定义ArrayAdapter
• 网格视图和适配器

您需要做的是:

• 为您的数据创建模型，例如:

• Create a model for your data like:

public class Movie {
    public long id;
    public String date;
    public String title;
    public double vote;

    public Movie(long id, String date, String title, double vote) {
        this.id = id;
        this.date = date;
        this.title = title;
        this.vote = vote;
    }
}

创建布局以显示电影详细信息，例如:

Create a layout to show movie details like:

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical">

    <TextView
        android:id="@+id/lbl_date"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content" />

    <TextView
        android:id="@+id/lbl_title"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content" />

    <TextView
        android:id="@+id/lbl_vote"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content" />

</LinearLayout>

更改适配器以处理电影，而不是 String ，例如:

public class MovieListAdapter extends ArrayAdapter<Movie > {
    public MovieListAdapter(Context context, List<Movie> objects) {
        super(context, 0, objects);
    }

    @Override
    public View getView(int position, View convertView, ViewGroup parent) {
        if (convertView == null) {
            convertView = LayoutInflater.from(getContext()).inflate(R.layout.movie_item, parent, false);
        }

        ((TextView) convertView.findViewById(R.id.lbl_date))
                .setText(getItem(position).date);

        ((TextView) convertView.findViewById(R.id.lbl_title))
                .setText(getItem(position).title);

        ((TextView) convertView.findViewById(R.id.lbl_vote))
                .setText(String.valueOf(getItem(position).vote));

        return convertView;
    }
}

最后在您的for循环之后设置适配器:

Finally set the adapter after your for loop like:

private void getMovieDataFromJson(String JsonString) throws JSONException {
    JSONObject jsonObject = new JSONObject(JsonString);
    JSONArray results = jsonObject.getJSONArray("results");

    ArrayList<Movie> movies = new ArrayList<>();

    for (int i=0; i<results.length(); i++){
        String title = results.getJSONObject(i).getString("original_title");
        String date = results.getJSONObject(i).getString("release_date");
        long id = results.getJSONObject(i).getLong("id");
        double vote = results.getJSONObject(i).getDouble("vote_average");

        movies.add(new Movie(id, date, title, vote));
    }

    myMoviesListView.setAdapter(new MovieListAdapter(MainActivity.this, movies));
}

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