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[BUG] AddListener does not work

Discussion in 'Immediate Mode GUI (IMGUI)' started by Wattosan, May 30, 2017.

  1. Wattosan

    Wattosan

    Joined:
    Mar 22, 2013
    Posts:
    450
    Using Unity version 5.5.2f1.

    Code (CSharp):
    1. GameObject go = Instantiate(mapEntryObject, MapGrid, false);
    2. Button button = go.GetComponent<Button>();
    3. button.onClick.AddListener(DisableActivePanel);
    4. Debug.Log("added the listener");
    I am instantiating two objects at runtime (this is code in a for loop). After this I get the button and add the listener. The Debug.Log gets called, which means this code actually runs and no errors are encountered. However, when I look at the instantiated objects in the scene, the button does not have any OnClick() events added to it.
     
    Wattosan, May 30, 2017
    #1

  2. karl_jones

    karl_jones

    Unity Technologies

    Joined:
    May 5, 2015
    Posts:
    7,850
    This is not a bug. The ones shown in the editor are persistent listeners(not added via script). If you want to add a persistent listener by script this can be done using the Editor api(wont work in a build). This is used for setting up event listeners so that they can be serialised in the scene, not for runtime use.
    https://docs.unity3d.com/ScriptReference/Events.UnityEventTools.AddPersistentListener.html
     
    karl_jones, May 31, 2017
    #2

  3. Wattosan

    Wattosan

    Joined:
    Mar 22, 2013
    Posts:
    450
    Thank you! You're correct that it works. Why doesn't the persistent listener work in a build?
     
    Wattosan, May 31, 2017
    #3

  4. karl_jones

    karl_jones

    Unity Technologies

    Joined:
    May 5, 2015
    Posts:
    7,850
    Persistent listeners are stored in the scene. They persist between scene reloads or play/stop a scene in the editor. You can't make persistent changes to a scene in a build, so the option is Editor only. It would be nice to see the non persistent listeners for an event though, perhaps in the future.
     
    karl_jones, May 31, 2017
    #4

  5. n7pankake

    n7pankake

    Joined:
    Nov 18, 2017
    Posts:
    18
    And how we can click objects then ?
     
    n7pankake, Apr 30, 2019
    #5

  6. MaDDoX

    MaDDoX

    Joined:
    Nov 10, 2009
    Posts:
    764
    MaDDoX, Oct 28, 2019
    #6
    pmain8 likes this.