说明

可使用Unity的Device Simulator在编辑器模式下测试UI在各种移动设备上的显示效果。

将下面的脚本挂在顶层UI节点（通常应是一个背景Panel）即可。（有时其后面应还有一个Bg，它不用被限制在安全区内显示）
UiAdaptScreenSafeArea.cs

using System.Collections;
using System.Collections.Generic;
using UnityEngine;

[RequireComponent(typeof(RectTransform))]
public class UiAdaptScreenSafeArea : MonoBehaviour
{
    private RectTransform _rectTrans;
    private void Start()
    {
        Init();
        AdaptAnchorsValue();
    }

    private void Init()
    {
        _rectTrans = GetComponent<RectTransform>();

        _rectTrans.anchorMin = Vector2.zero;
        _rectTrans.anchorMax = Vector2.one;
        _rectTrans.anchoredPosition = Vector2.zero;
        _rectTrans.sizeDelta = Vector2.zero;

    }

    private void AdaptAnchorsValue()
    {
        var maxWidth = Display.main.systemWidth;
        var maxHeight = Display.main.systemHeight;
        var safeArea = UnityEngine.Screen.safeArea;
        var anchorMin = safeArea.position;
        var anchorMax = safeArea.position + safeArea.size;
        anchorMin.x /= maxWidth;
        anchorMin.y /= maxHeight;
        anchorMax.x /= maxWidth;
        anchorMax.y /= maxHeight;

        _rectTrans.anchorMin = anchorMin;
        _rectTrans.anchorMax = anchorMax;
    }
}