How to update UI image mid-game (Unity, C#)

Question

Hello, I'm trying to update a UI image when you click on different buttons. I am currently able to change the UI image only at the start of the game by using C# scripts to set the UI image's source image to something. I believe I have written the correct code that adds a layer of image changing to change the UI image - basically, I'm able to change the image of the image that directly changes the image of the UI image. When I plug this line of code into Start() it works perfectly. When I put it in a function and assign a button to fire the program when it is clicked on, it doesn't work. It also doesn't work when I plug the code into Update() which makes me think that my code only allows for the image change at the start of the game. Here is my code: " public Sprite FrogImage;

 void Start()
 {

 }

 public void FClickCharacter()
 {
     GameObject.FindWithTag("ChoosedCharacter").GetComponent<SelectedCharacter>().sprite1 = FrogImage;
 }
 public void MClickCharacter()
 {

 }
 public void PClickCharacter()
 {

 }
 public void VClickCharacter()
 {

 }

" FrogImage is an image I set in Unity, and "SelectedCharacter" is a different script containing "sprite1" which changes the UI image. When I assign FClickCharacter to a button and click the button it doesn't work. When I put it into Start() the UI image is set to "FrogImage" at the start of the game. When I put it into Update() it just is the original value of sprite1. Any suggestions or tips would be very appreciated, thanks!

Answer 1

Answer by mak431020 · Aug 21, 2021 at 05:42 AM

First you have to declare a Image and find the gameobject sprite in the start or awake then store the gameobject sprite in the image. Then you can do what you want

 Image frogSprite;
 
 void Start()
  {
     frogSprite = GameObject.FindWithTag("ChoosedCharacter").GetComponent<SelectedCharacter>().sprite1;
  }
  public void FClickCharacter()
  {
       frogSprite = FrogImage;
  }

Add comment · Share

Answer 2

Frm what I see in you code, I'm actually surprised you get it working in the start method. If I understand well, sprite1 is a member of the SelectedCharacter class. You could use a property in the SelectedCharacter class to update the image when you set the sprite value like this.

 using UnityEngine;
 using UnityEngine.UI;
 
 public class SelectedCharacter : MonoBehaviour
 {
     private Image image;
 
     private Sprite sprite1;
     public Sprite Sprite1{
         get => sprite1;
         set {
             sprite1 = value;
             image.sprite = sprite1;
         }
     }
 
     void Awake() {
         image = GetComponent<Image>();
     }
 
     //Rest of your code
 }

This way, you can now assign the value in your function with this call

 public void FClickCharacter()
 {
     GameObject.FindWithTag("ChoosedCharacter").GetComponent<SelectedCharacter>().Sprite1 = FrogImage;
 }

It should automatically update the image sprite when changing the value. If it doesn't work, you should check in the scene view when being in play mode if you have a character with the ChoosedCharacter tag and if this object is enabled. If not, the Find method will fail.

How to update UI image mid-game (Unity, C#)

2 Replies

Your answer

Follow this Question

Related Questions