Search Unity

Question Having trouble with ListView's itemMake/itemBind parameters

Discussion in 'UI Toolkit' started by niel-archer, Sep 26, 2021.

  1. niel-archer

    niel-archer

    Joined:
    Nov 29, 2016
    Posts:
    17
    I'm following this example for ListView https://docs.unity3d.com/Packages/com.unity.ui@1.0/api/UnityEngine.UIElements.ListView.html#UnityEngine_UIElements_ListView and I need to use a list entry more complicated than a simple Label.

    I've created a class (called ListEntry)., that extends VisualElement, to hold four labels ListEntry will contain a method to do the binding of another object (ListItem) to the ListEntry.

    How would I create the itemMake and ItemBind parameters to do that, or am I fundamentally misunderstanding this?
     
    Last edited: Sep 27, 2021
    niel-archer, Sep 26, 2021
    #1

  2. HugoBD-Unity

    HugoBD-Unity

    Unity Technologies

    Joined:
    May 14, 2018
    Posts:
    499
    Hi @niel-archer !

    There's a simple example on how to set up a ListView in the sample window. (Window/UI Toolkit/Samples)

    Would something like this work for your use case ?
    Func<VisualElement> makeItem = () => new ListEntry();
    
Action<VisualElement, int> bindItem = (e, i) => (e as ListEntry).item = items[i];
     
    HugoBD-Unity, Sep 27, 2021
    #2

  3. niel-archer

    niel-archer

    Joined:
    Nov 29, 2016
    Posts:
    17
    I saw that example, and as stated in OP, I have a more complicated entry with more than one field. I have found a way to do it using similar method to that example, but I would really like to put the code into the class for the new ListEntry so that it is all together and I don't have to crawl through hundreds or thousands of lines of code to find it if/when it needs to be updated.
     
    niel-archer, Sep 27, 2021
    #3

  4. HugoBD-Unity

    HugoBD-Unity

    Unity Technologies

    Joined:
    May 14, 2018
    Posts:
    499
    I think I understand. You could add a BindItem method in your ListEntry class that holds the binging logic. Then call this method in the bindItem callback. The result would look something like this.
    Code (CSharp):
    1. Action<VisualElement, int> bindItem = (e, i) => (e as ListEntry).BindItem(items[i]);
    Does it answer your question?
     
    HugoBD-Unity, Sep 27, 2021
    #4

  5. niel-archer

    niel-archer

    Joined:
    Nov 29, 2016
    Posts:
    17
    Many thanks. That looks like what I am after. I will give it a try as soon as I can find time.
     
    niel-archer, Sep 28, 2021
    #5
    HugoBD-Unity likes this.

  6. niel-archer

    niel-archer

    Joined:
    Nov 29, 2016
    Posts:
    17
    Thanks for your help, that was exactly what I needed.
     
    niel-archer, Sep 28, 2021
    #6