Unity/UIDropdown

Dropdown追加方法

1. UI/Dropdownを追加
2. Dropdownを選択肢Inspectorのoptionsから選択項目を編集する

Dropdown選択値取得サンプル

using UnityEngine;
using UnityEngine.UI;
public class Example : MonoBehaviour
{
    Dropdown m_Dropdown;
    public Text m_Text;
    void Start()
    {
        //Fetch the Dropdown GameObject
        m_Dropdown = GetComponent<Dropdown>();
        //Add listener for when the value of the Dropdown changes, to take action
        m_Dropdown.onValueChanged.AddListener(delegate {
                DropdownValueChanged(m_Dropdown);
            });
        //Initialise the Text to say the first value of the Dropdown
        m_Text.text = "First Value : " + m_Dropdown.value;
    }
    //Ouput the new value of the Dropdown into Text
    void DropdownValueChanged(Dropdown change)
    {
        m_Text.text =  "New Value : " + change.value;
    }
}

参考：https://docs.unity3d.com/ja/current/ScriptReference/UI.Dropdown-onValueChanged.html

選択項目の高さが狭い場合

templates/viewportのscaleのyを1から3とかにする

Dropdownの選択項目追加

using UnityEngine;
using UnityEngine.UI;
using System.Collections.Generic;
public class Example : MonoBehaviour
{
    //Use these for adding options to the Dropdown List
    Dropdown.OptionData m_NewData, m_NewData2;
    //The list of messages for the Dropdown
    List<Dropdown.OptionData> m_Messages = new List<Dropdown.OptionData>();
    //This is the Dropdown
    Dropdown m_Dropdown;
    string m_MyString;
    int m_Index;
    void Start()
    {
        //Fetch the Dropdown GameObject the script is attached to
        m_Dropdown = GetComponent<Dropdown>();
        //Clear the old options of the Dropdown menu
        m_Dropdown.ClearOptions();

        //Create a new option for the Dropdown menu which reads "Option 1" and add to messages List
        m_NewData = new Dropdown.OptionData();
        m_NewData.text = "Option 1";
        m_Messages.Add(m_NewData);

        //Create a new option for the Dropdown menu which reads "Option 2" and add to messages List
        m_NewData2 = new Dropdown.OptionData();
        m_NewData2.text = "Option 2";
        m_Messages.Add(m_NewData2);

        //Take each entry in the message List
        foreach (Dropdown.OptionData message in m_Messages)
        {
            //Add each entry to the Dropdown
            m_Dropdown.options.Add(message);
            //Make the index equal to the total number of entries
            m_Index = m_Messages.Count - 1;
        }
    }
}

参考：https://docs.unity3d.com/ja/current/ScriptReference/UI.Dropdown-options.html

ListデータをDropdownへ反映

List<string> cars = new List<string>();
string car = "jiro";
Dropdown carDropdown;
void Start()
{
    carDropdown = GameObject.Find("/Canvas/CarDropdown").GetComponent<Dropdown>();
    carDropdown.onValueChanged.AddListener(delegate {
       CarDropdownValueChanged(carDropdown);
    });
}
void InitDropdown()
{
    cars.Add("taro");
    cars.Add("jiro");
    List<Dropdown.OptionData> optionMessages = new List<Dropdown.OptionData>();
    Dropdown optionDropdown = GameObject.Find("CarDropdown").GetComponent<Dropdown>();
    optionDropdown.ClearOptions();
    foreach (string car in cars)
    {
        Dropdown.OptionData optionData;
        optionData = new Dropdown.OptionData();
        optionData.text = car;
        optionMessages.Add(optionData);
    }
    foreach (Dropdown.OptionData message in optionMessages)
    {
        optionDropdown.options.Add(message);
    }
    optionDropdown.value = cars.IndexOf(car);
}

void CarDropdownValueChanged(Dropdown change)
{
   car = cars[change.value];
}