For loop with UI buttons alternative in new UI?

Question

In an old project I had old UI and I had an loop that went through around 30 buttons. Each button had its own index that I used to do some action.

 for (var i = 2; i<=30; i++) {
 
     if (GUI.Button(Rect((28.2/100)*width, offset+(perc_btnY/100)*height , 80, 50), "+10")){ //Buy btn
     // tons of code that uses index of this button
         }
     }

So if button had index of 5, I would do something in some array at position 5 in other script, thus giving me freedom to use only that for loop for 30 buttons and get unique behavior for each of them.

Is there an alternative for new UI ? I know that I can instantiate buttons on canvas but can I somehow replicate all my functionality with one for loop?

What I need to do in this example :

 // pseudo code 
 
 for (var i = 2; i<=30; i++) {
  
      // if user clicks on this button
        InfoClass.Something.SomeList[indexOfThisButton].Remove(5);
      }

I don't like idea of having one script for each button that would hold an index variable and control button. Somehow idea of having 30 scripts on one UI element doesn't seem right.

Thanks.

Answer 1

Best Answer

Answer by drod7425 · Mar 23, 2015 at 12:49 PM

With the new UI, you don't need to constantly check if a button is being clicked. Instead, you add OnClick listeners to the button:

 public Button[] buttons;
 
 void Start () {
     for(int i = 0; i < buttons.Length;i++ ) {
         int capturedIterator = i;
         buttons[i].onClick.AddListener(() => DoSomething(capturedIterator));
     }
 }
 
 public void DoSomething(int index) {
     
 }

I haven't tested that code, but it should be something generally like this. Also, make sure you are using UnityEngine.UI.

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Answer 2

Answer by YoungDeveloper · Mar 23, 2015 at 12:41 PM

Create the buttons in scene or generate them via script and store them in array/list - public inspector array.

If you are adding buttons from inspector:

 //pseudocode
 
 //using UnityEngine.UI;
 
 public Image[] buttons;
 
 for(int i = 0; i < buttons.Length; i++){
     Debug.Log(buttons[i].gameObject.name);
 }

 //if you want to remove the elements
 for(int i = buttons.Length-1; i >= 0 ; i--){
     Destroy(buttons[i].gameObject);
 }

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Hamsterlings · Mar 23, 2015 at 12:48 PM 0

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Thanks for reply!

$$anonymous$$y initial plan was along those lines as well.

How can I tell which button did user press without assigning new script to that button though ?

I know that I can create script and use lambda expression, for example, to find the button in list, but that means that I will have 30 buttons with 30 scripts.

Whole point of code in my post is to use one for loop to create and recognize which button was pressed by index.

YoungDeveloper · Mar 23, 2015 at 01:07 PM 0

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Yesterday i created same thing for the project you are asking. I had buttons in a scroll list, in user specified amount. $$anonymous$$y setup was that all those buttons were a child under one parent. Each button contains a class (inherited from mono) which can be added on gameobject. When i generate button in for loop i getcomponent of that class and set i index for that button. Each button also contains click event, when that is clicked i run method wich has no params, that method is located in the same script i store it's button index. From that point i launch buttons manager button and simply pass that index to know which of all i pressed.

drod7425 · Mar 23, 2015 at 01:17 PM 0

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You can do what you are asking about with my answer. Just put Debug.Log(index); in the DoSomething method.

For loop with UI buttons alternative in new UI?

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