如何设置ArrayList <HashMap<String,String> &gt;在ArrayAdapter中

Question

Can we set an ArrayList containing HashMap into an ArrayAdapter ?

I'm using:

ArrayList<HashMap<String,String>> items = new ArrayList<HashMap<String,String>>();
ArrayAdapter<ArrayList<HashMap<String, String>>> ad = new ArrayAdapter<ArrayList<HashMap<String,String>>>(this, android.R.layout.simple_list_item_1,items);

but this gives me an error saying:

The constructor ArrayAdapter>>(searchname, int, ArrayList>) is undefined

Answer 1

ArrayAdapter wants to know the type of the items inside the list, not the type of the list itself. Remove the enclosing ArrayList<> and it should work.

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

ArrayAdapter<HashMap<String, String>> ad =
        new ArrayAdapter<HashMap<String,String>>(this,
            android.R.layout.simple_list_item_1,items);

Answer 2

have a look at this link Android Array Adapter with ArrayList and ListView not updating when the arraylist is changed .

basically you need to add your ArrayList into the ArrayAdapter through the add method.

Answer 3

You can convert the type HashMap<String,String>> to a class. For example, if the keys of the hashmap are countries and the values are lenguages, you can make a class called "Country" with this two variables (country,language). Then the AdapterClass have to extend the ArrayAdapter<Country> , in the getView method you can access both variables of each Country.