How to modify RectTransform properties in script [Unity 4.6 beta]

Hey Friend Just Try This To Change Position and Width of an UI gameObject

if you want to use instance of an object use This leftButton.GetComponent<RectTransform>().anchoredPosition = new Vector2(-125, -36f); rightButton.GetComponent<RectTransform>().sizeDelta = new Vector2(x, y);

And if want to put script on a UI object then try this to change height and width

GetComponent<RectTransform>().anchoredPosition = new Vector2(-125, -36f);
GetComponent<RectTransform>().sizeDelta = new Vector2(x, y)

One day researching. I found an extension that can help us to deal with new UI system. u can improve this extension if you want.

public static class RectTransformExtensions
{
    public static void SetDefaultScale(this RectTransform trans) {
        trans.localScale = new Vector3(1, 1, 1);
    }
    public static void SetPivotAndAnchors(this RectTransform trans, Vector2 aVec) {
        trans.pivot = aVec;
        trans.anchorMin = aVec;
        trans.anchorMax = aVec;
    }

    public static Vector2 GetSize(this RectTransform trans) {
        return trans.rect.size;
    }
    public static float GetWidth(this RectTransform trans) {
        return trans.rect.width;
    }
    public static float GetHeight(this RectTransform trans) {
        return trans.rect.height;
    }

    public static void SetPositionOfPivot(this RectTransform trans, Vector2 newPos) {
        trans.localPosition = new Vector3(newPos.x, newPos.y, trans.localPosition.z);
    }

    public static void SetLeftBottomPosition(this RectTransform trans, Vector2 newPos) {
        trans.localPosition = new Vector3(newPos.x + (trans.pivot.x * trans.rect.width), newPos.y + (trans.pivot.y * trans.rect.height), trans.localPosition.z);
    }
    public static void SetLeftTopPosition(this RectTransform trans, Vector2 newPos) {
        trans.localPosition = new Vector3(newPos.x + (trans.pivot.x * trans.rect.width), newPos.y - ((1f - trans.pivot.y) * trans.rect.height), trans.localPosition.z);
    }
    public static void SetRightBottomPosition(this RectTransform trans, Vector2 newPos) {
        trans.localPosition = new Vector3(newPos.x - ((1f - trans.pivot.x) * trans.rect.width), newPos.y + (trans.pivot.y * trans.rect.height), trans.localPosition.z);
    }
    public static void SetRightTopPosition(this RectTransform trans, Vector2 newPos) {
        trans.localPosition = new Vector3(newPos.x - ((1f - trans.pivot.x) * trans.rect.width), newPos.y - ((1f - trans.pivot.y) * trans.rect.height), trans.localPosition.z);
    }

    public static void SetSize(this RectTransform trans, Vector2 newSize) {
        Vector2 oldSize = trans.rect.size;
        Vector2 deltaSize = newSize - oldSize;
        trans.offsetMin = trans.offsetMin - new Vector2(deltaSize.x * trans.pivot.x, deltaSize.y * trans.pivot.y);
        trans.offsetMax = trans.offsetMax + new Vector2(deltaSize.x * (1f - trans.pivot.x), deltaSize.y * (1f - trans.pivot.y));
    }
    public static void SetWidth(this RectTransform trans, float newSize) {
        SetSize(trans, new Vector2(newSize, trans.rect.size.y));
    }
    public static void SetHeight(this RectTransform trans, float newSize) {
        SetSize(trans, new Vector2(trans.rect.size.x, newSize));
    }
}

The source code I found from here: http://orbcreation.com