Hide/show panel using dropdown Unity

Question

I just started a unity project for some basic game stuff.

This might be wrong question or invalid process.

I have done hide/show panel on button click, Now I want to hide/show after value change of dropdown.

I have two panel, one for basic info and other for security info. And after select dropdown value I want to display one of these panel and hide second panel.

But I have no idea how to achieve that.

I am tring some basic logic and stuck on that.

What I did:

using UnityEngine;
using UnityEngine.UI;
using UnityEngine.Events;
using System.Collections;

public class WithrowModalPanel : MonoBehaviour
{

    public Button cancelButton;
    public GameObject modalPanelObject;
    public GameObject modalPanelObjectAdvance;
    public Dropdown myDropdown;

    private static WithrowModalPanel modalPanel;

    public static WithrowModalPanel Instance()
    {
        if (!modalPanel)
        {
            modalPanel = FindObjectOfType(typeof(WithrowModalPanel)) as WithrowModalPanel;
            if (!modalPanel)
                Debug.LogError("There needs to be one active ModalPanel script on a GameObject in your scene.");
        }

        return modalPanel;
    }

    void Update()
    {
        switch (myDropdown.value)
        {
            case 1:
                Debug.Log("Basic panel!");
                modalPanelObject.SetActive(true);
                modalPanelObjectAdvance.SetActive(false);
                break;

            case 2:
                Debug.Log("Advance panel!");
                modalPanelObjectAdvance.SetActive(true);
                modalPanelObject.SetActive(false);
                break;
        }
    }
}

I just stared unity and didnt have much idea about its structure.

Answer 1

Note that Dropdown.value is 0-base indexed so the first entry is 0 not 1. I don't know your complete setup but I guess that was the main issue in your attempt.

Then Dropdowns have an event onValueChanged instead of doing it in Update you should rather register a listener to it

private void Start()
{
    // Just to be sure it is always only added once
    // I have the habit to remove before adding a listener
    // This is valid even if the listener was not added yet
    myDropdown.onValueChanged.RemoveListener(HandleValueChanged);
    myDropdown.onValueChanged.AddListener(HandleValueChanged);
}

private void OnDestroy()
{
    // To avoid errors also remove listeners as soon as they
    // are not needed anymore
    // Otherwise in the case this object is destroyed but the dropdown is not
    // it would still try to call your listener -> Exception
    myDropdown.onValueChanged.RemoveListener(HandleValueChanged);
}

private void HandleValueChanged(int newValue)
{
    switch (newValue)
    {
        case 0:
            Debug.Log("Basic panel!");
            modalPanelObject.SetActive(true);
            modalPanelObjectAdvance.SetActive(false);
            break;

        case 1:
            Debug.Log("Advance panel!");
            modalPanelObjectAdvance.SetActive(true);
            modalPanelObject.SetActive(false);
            break;
    }
}

---

Hint: you could use the generic of FindObjectOfType

modalPanel = FindObjectOfType<WithrowModalPanel>();