Relative and absolute positioning C# example

This example demonstrates the difference between relative and absolute positioning.

Example overview

The example uses the automatic layout system to add boxes to a window and calculate their positions. One box demonstrates a relative offset of 25 px, while another box demonstrates the absolute position of 25 px, 25 px.

You can find the completed files that this example creates in this GitHub repository.

先决条件

This guide is for developers familiar with the Unity Editor, UI Toolkit, and C# scripting. Before you start, get familiar with the following:

Create the example with a C# script

Create a custom Editor window and add all the boxes with a C# script: four boxes with gray backgrounds for comparison purposes; one box with black background with the absolute position; one box with purple background with the relative position.

Create a Unity project with any template.
Right-click in the Project window, then select Create > UI Toolkit > Editor Window.
In the C# box of the UI Toolkit Editor Window Creator window, enter PositioningTestWindow.
Clear the UXML and USS checkboxes.
Select Confirm. This creates a C# file called PositioningTestWindow.cs.

Replace PositioningTestWindow.cs with the following content:

using UnityEditor;
using UnityEngine;
using UnityEngine.UIElements;

public class PositioningTestWindow : EditorWindow
{
    [MenuItem("Window/UI Toolkit/Positioning Test Window")]
    public static void ShowExample()
    {
        var wnd = GetWindow<PositioningTestWindow>();
        wnd.titleContent = new GUIContent("Positioning Test Window");
    }

    public void CreateGUI()
    {
        for (int i = 0; i < 4; i++)
        {
            var temp = new VisualElement();
            temp.style.width = 70;
            temp.style.height = 70;
            temp.style.marginBottom = 2;
            temp.style.backgroundColor = Color.gray;
            rootVisualElement.Add(temp);
        }

        // Relative positioning
        var relative = new Label("Relative\nPos\n25, 0");
        relative.style.width = 70;
        relative.style.height = 70;
        relative.style.left = 25;
        relative.style.marginBottom = 2;
        relative.style.backgroundColor = new Color(0.2165094f, 0, 0.254717f);
        rootVisualElement.Add(relative);

        // Absolute positioning
        var absolutePositionElement = new Label("Absolute\nPos\n25, 25");
        absolutePositionElement.style.position = Position.Absolute;
        absolutePositionElement.style.top = 25;
        absolutePositionElement.style.left = 25;
        absolutePositionElement.style.width = 70;
        absolutePositionElement.style.height = 70;
        absolutePositionElement.style.backgroundColor = Color.black;
        rootVisualElement.Add(absolutePositionElement);
    }
}

To see the example, from the menu, select Window > UI Toolkit > Positioning Test Window.

其他资源

Structure UI examples

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