EDIT:
I saw the question is not exact!
I get a different layout when building my game and different layout when starting in the editor!
This is when i BUILD the project:
This is when i start in the Game preview:
I add the elements through code, i have prefabs for it.
My code:
loginForm = Resources.Load<GameObject>("UI/loginForm");
EventHelper = Resources.Load<GameObject>("UI/UI_base/EventSystem");
UIHelper = Resources.Load<GameObject>("UI/UI_base/UIHandler");
GameObject.Instantiate(EventHelper, new Vector3(0, 0, 0), Quaternion.identity);
GameObject UIObj = (GameObject)GameObject.Instantiate(UIHelper, UIHelper.transform.position, UIHelper.transform.rotation);
GameObject loginObj = (GameObject)GameObject.Instantiate(loginForm, loginForm.transform.position, loginForm.transform.rotation);
loginObj.transform.SetParent(UIObj.transform, false);
I have been testing the 4.6 UI and to make this work, click your button in the scene, then scroll all the way down in the inspector. From there, you should see a onclick tab in the inspector on the bottom. Then click the plus, drag and drop a empty gameobject into the onclick tab, then drag the script into the empty gameobject. Then make a function called Instantiateobject. Then put the instantiated code in there. Remove everything but the Instantiated object.Save the code, then in the Onclick tab for the button, click the thing that says function. From there, select the script in the drop down, then click the instantiatedobject. That means when you click the button, it will instantiate the object. Then, you can add another gameobject in the onclick tab and you can drag one of the ui’s in it and click functions, select the gameobject name, and click SetActive(bool) and checkmark the button next to the functions button, and disable yhe UI to have in the SetActive in the OnClock. That means when you click it, it will activate the button.