How to change alpha of children

Question

in Unity I have a game object as parent and two child text-objects as children. Also there is an image child-object (three children altogether).

Now I want to change the alpha of the game-object's three children. How do I accomplish this programmatically?

I have this code but it doesn't work with text and image-objects:

public void setAlpha(float alpha) {
SpriteRenderer[] children = GetComponentsInChildren<SpriteRenderer>();
Color newColor;
foreach(SpriteRenderer child in children) {
    newColor = child.color;
    newColor.a = alpha;
    child.color = newColor;
    }
}

Answer 1

Your code would work if you were working with a SpriteRenderer.

You can accomplish that by changing the alpha channel of the color property of the Text and Image, very similar from what you did:

public void setAlpha(float alpha) {
    Color newColor;

    Image[] childrenImg = GetComponentsInChildren<Image>();
    foreach(Image img in childrenImg) {
        newColor = img.color;
        newColor.a = alpha;
        img.color = newColor;
    }

    Text[] childrenText = GetComponentsInChildren<Text>();
    foreach(Text text in childrenText) {
        newColor = text.color;
        newColor.a = alpha;
        text.color = newColor;
    }
}

Don't forget to include using UnityEngine.UI; on top of your script, as Text and Image are UI elements.