将实例添加到ArrayList

Question

我已经创建了一个新的ArrayList，我只需要向其添加实例，但是Java却说“无法解析符号'add'”。 我已经看了这个问题：（how to change from arrays to one array list），但我仍然收到错误消息

代码：

public class EventController {

     ArrayList<Event> events = new ArrayList<>();

Event e1 = new Event("Drake", "5th October 2019", "19:30-late", "Leeds", "First Direct Arena");
    Event e2 = new Event("Drake", "6th October 2019", "21:30-late", "Leeds", "First Direct Arena");
    Event e3 = new Event("Ed Sheeran", "21st October 2019", "19:00-late", "Leeds", "First Direct Arena");
    Event e4 = new Event("Ed Sheeran", "22nd October 2019", "20:30-late", "Leeds", "First Direct Arena");
    Event e5 = new Event("Jorja Smith", "3rd November 2019", "19:30-late", "Leeds", "First Direct Arena");
    Event e6 = new Event("Jorja Smith", "4rd November 2019", "20:30-late", "Leeds", "First Direct Arena");
    Event e7 = new Event("Coldplay", "15th December 2019", "17:30-late", "Leeds", "First Direct Arena");
    Event e8 = new Event("Coldplay", "16th December 2019", "19:30-late", "Leeds", "First Direct Arena");

    events.add(e1);
}

错误：

Answer 1

您需要将代码放入构造函数或函数中。

public class EventController {

    public EventController() {
       ArrayList<Event> events = new ArrayList<>();

       Event e1 = new Event("Drake", "5th October 2019", "19:30-late", "Leeds", "First Direct Arena");
       Event e2 = new Event("Drake", "6th October 2019", "21:30-late", "Leeds", "First Direct Arena");
       Event e3 = new Event("Ed Sheeran", "21st October 2019", "19:00-late", "Leeds", "First Direct Arena");
       Event e4 = new Event("Ed Sheeran", "22nd October 2019", "20:30-late", "Leeds", "First Direct Arena");
       Event e5 = new Event("Jorja Smith", "3rd November 2019", "19:30-late", "Leeds", "First Direct Arena");
       Event e6 = new Event("Jorja Smith", "4rd November 2019", "20:30-late", "Leeds", "First Direct Arena");
       Event e7 = new Event("Coldplay", "15th December 2019", "17:30-late", "Leeds", "First Direct Arena");
       Event e8 = new Event("Coldplay", "16th December 2019", "19:30-late", "Leeds", "First Direct Arena");

       events.add(e1);
    }
}

Answer 2

您必须将类扩展为Activity，或者可以在方法中编写代码以执行ArrayList（）的添加。