Access "Left", "Right", "Top" and "Bottom" of RectTransform via script

Hi, I know this is an old thread but I landed here in 2019 so I guess this is still valuable. I just created a little script to answer your question. Create a new script called RectTransformExtensions (or whatever you want), and put that in there:

 using UnityEngine;

 public static class RectTransformExtensions
 {
     public static void SetLeft(this RectTransform rt, float left)
     {
         rt.offsetMin = new Vector2(left, rt.offsetMin.y);
     }
 
     public static void SetRight(this RectTransform rt, float right)
     {
         rt.offsetMax = new Vector2(-right, rt.offsetMax.y);
     }
 
     public static void SetTop(this RectTransform rt, float top)
     {
         rt.offsetMax = new Vector2(rt.offsetMax.x, -top);
     }
 
     public static void SetBottom(this RectTransform rt, float bottom)
     {
         rt.offsetMin = new Vector2(rt.offsetMin.x, bottom);
     }
 }

Now you can call these methods like this :

 myRectTransform.SetLeft(100);

Hope this helps!

Actually, we cannot access the top, left, right, bottom individually as I know. so "Left", "Right", "Top" and "Bottom" of RectTransform properties so we have offsetMin and offsetMax which return a vector as follows

PanelSpacerRectTransform.offsetMin = new Vector2(0, 0); // new Vector2(left, bottom); PanelSpacerRectTransform.offsetMax = new Vector2(-360, -0); // new Vector2(-right, -top);

The easiest and cleanest solution is to simply use RectTransform.SetInsetAndSizeFromParentEdge. See this page for more information : https://docs.unity3d.com/462/Documentation/ScriptReference/RectTransform.SetInsetAndSizeFromParentEdge.html

If you want your object to fill the entire space of the parent, just do this:

         RectTransform rectTransform = gameObjectButton.GetComponent<RectTransform>();
         rectTransform .SetInsetAndSizeFromParentEdge(RectTransform.Edge.Bottom, 0, 0);
         rectTransform .SetInsetAndSizeFromParentEdge(RectTransform.Edge.Top, 0, 0);
         rectTransform .SetInsetAndSizeFromParentEdge(RectTransform.Edge.Left, 0, 0);
         rectTransform .SetInsetAndSizeFromParentEdge(RectTransform.Edge.Right, 0, 0);

Bump. Hope it gives you some idea.

http://forum.unity3d.com/threads/setting-top-and-bottom-on-a-recttransform.265415/

@Eldoir thanks for this!