java - 将 Hashmap 数组添加到 Listview

Question

我是 Android 编程的初学者，我在完成这个简单的任务时遇到了很多麻烦。

我有一个数组列表:

ArrayList<HashMap<String, String>> tableList = new ArrayList<HashMap<String, String>>();

我想将每个键/值对添加到 ListView。

如何将它们添加到 ListView？我在网上看到了无数关于使用适配器的解释，但它们都使用了我一无所知的变量。

Answer 1

构建您自己的适配器类:

public class MyAdapter extends BaseAdapter {

    private Activity activity;
    private HashMap<String, String> map;

    public MyAdapter(Activity activity, HashMap<String, String> map) {
        this.activity = activity;
        this.map = map;
    }

    public int getCount() {
        return map.size();
    }    

    public View getView(final int position, View convertView, ViewGroup parent) {
        if (convertView == null) {
            LayoutInflater inflater = (LayoutInflater) activity
                    .getSystemService(Context.LAYOUT_INFLATER_SERVICE);
            convertView = inflater.inflate(R.layout.my_list_item,
                    null);
        }

            // Recommended to use a list as the dataset passed in the constructor.
            // Otherwise not sure how you going to map a position to an index in the dataset.
            String key = // get a key from the HashMap above
            String value = map.get(key);

            TextView keyView = convertView.findViewById(R.id.item_key);
            keyView.setText(key);

            TextView valueView = convertView.findViewById(R.id.item_value);
            valueView .setText(value);

        return convertView;
    }    
}

然后，将其传递给您的 ListView setAdapter 方法:

MyAdapter myAdapter = new MyAdapter(this, map);
ListView listview = (ListView) findViewById(R.id.listview);
listview.setAdapter(myAdapter);

示例布局/my_list_item.xml:

<LinearLayout xmlns:android:http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
>

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

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