Dropdown.options

Description

The list of possible options. A text string and an image can be specified for each option.

This is the list of options within the Dropdown. Each option contains Text and/or image data that you can specify using OptionData before adding to the Dropdown list. This also unlocks the ability to edit the Dropdown, including the insertion, removal, and finding of options, as well as other useful tools.

//Create a new Dropdown GameObject by going to the Hierarchy and clicking Create>UI>Dropdown. Attach this script to the Dropdown GameObject.

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;
        }
    }

//This OnGUI function is used here for a quick demonstration. See the UI Section for more information about setting up your own UI.
    void OnGUI()
    {
        //TextField for user to type new entry to add to Dropdown
        m_MyString = GUI.TextField(new Rect(0, 40, 100, 40), m_MyString);

        //Press the "Add" Button to add a new entry to the Dropdown
        if (GUI.Button(new Rect(0, 0, 100, 40), "Add"))
        {
            //Make the index the last number of entries
            m_Index = m_Messages.Count;
            //Create a temporary option
            Dropdown.OptionData temp = new Dropdown.OptionData();
            //Make the option the data from the TextField
            temp.text = m_MyString;

            //Update the messages list with the TextField data
            m_Messages.Add(temp);

            //Add the Textfield data to the Dropdown
            m_Dropdown.options.Insert(m_Index, temp);
        }

        //Press the "Remove" button to delete the selected option
        if (GUI.Button(new Rect(110, 0, 100, 40), "Remove"))
        {
            //Remove the current selected item from the Dropdown from the messages List
            m_Messages.RemoveAt(m_Dropdown.value);
            //Remove the current selection from the Dropdown
            m_Dropdown.options.RemoveAt(m_Dropdown.value);
        }
    }
}