将列表添加到ArrayList <String> 并显示在ListView上

Question

I want to make a ListView from the time that I get from a TimePicker' I succeed to add the time into a variable. but when I'm trying to add them into the ListView I don't get anything.

    addArray = new ArrayList<String>();
    ArrayAdapter<String> adapter = new ArrayAdapter(chart_houres_cosher.this,android.R.layout.simple_list_item_1,addArray);
    ListView listView = (ListView) findViewById(R.id.leassons);
    listView.setAdapter(adapter);

Clicked button

    textView.setText( firstHouer + " : " + firstdMinute + " - " + seccoundHouer + " : " + seccoundMinute );
    addArray.add(firstHouer + " : " + firstdMinute + " - " + seccoundHouer + " : " + seccoundMinute);

I can see the outcome on the TextView but not on the ListView.

Answer 1

Once you change the data of adapter you have to invoke notifyDataSetChanged() to see the effects in the list view.

textView.setText( firstHouer + " : " + firstdMinute + " - " + seccoundHouer + " : " + seccoundMinute );
addArray.add(firstHouer + " : " + firstdMinute + " - " + seccoundHouer + " : " + seccoundMinute);
addArray.notifyDataSetChanged();
//^^^^^^^^^^^^^^^^^^^
// once adapter is linked and later data source is modified , notify it
// only then adapter go though the data source 
//and update the listView/RecyclerView accordingly

Answer 2

And where is your data? From your code you are trying to add an empty Array.

addArray = new ArrayList<String>();

You just declare addArray, it dosen't have any data in it. And you are adding empty array into ListView.