覆盖 ArrayAdapter 的 getView 以填充 3 个 Textview

Question

从我的 Activity，我正在调用我的 MovieTask 扩展 AsyncTask。我在 MovieTask 的 doInBackground 方法中成功解析了来自服务器的 Json 响应。

现在，我的 activity 中有一个列表视图，我想使用扩展 ArrayAdapter.

的 MovieListAdapter 填充列表视图

对于每个视图（即一行），我想填充 3 TextViews。我正在重写 MovieListAdapter 的 getView 方法来填充相同的内容。但是我不明白如何将数据从我的 activity 发送到 getView 方法到 getView 方法来填充文本视图？

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

    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 ?
     }

}

Answer 1

当您在 AdapterView 上 setAdapter() 例如 ListView 时，getView() 会在内部调用，并且从中返回的视图会填充到 AdapterView.

您可能想阅读并了解 AdapterView 和 Adapter 的工作原理。继续阅读这里的一些文档：

您需要做的是：

为您的数据创建一个模型，例如：

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：

<?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>

更改您的适配器以处理 Movie 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 for 循环之后设置适配器，例如：

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));
}

覆盖 ArrayAdapter 的 getView 以填充 3 个 Textview

Overriding getView of ArrayAdapter to fill 3 Textviews

android

listview

android-adapter