1、打开Unity，新建一个空工程，具体如下图
2、在场景中添加 Cube，并把视图改为2D，布局如下图
3、在工程中，新建一个脚本，命名为 DrawRectangle2D，并右键脚本 Open C# Project 打开，具体如下图
4、在打开的脚本上编写代码，具体代码和代码说明如下图
5、脚本具体内容如下：using UnityEngine;public class DrawRectangle2D : MonoBehaviour { // Update is called once per frame void Update () { if (Input.GetKeyDown(KeyCode.A)) { ToDrawRectangle2D(transform, 1, 4, 3); } } private static LineRenderer GetLineRenderer(Transform t) { LineRenderer lr = t.GetComponent<LineRenderer>(); if (lr == null) { lr = t.gameObject.AddComponent<LineRenderer>(); } lr.startWidth = 0.1f; lr.endWidth = 0.1f; return lr; } //绘制空心长方形2D //distance指的是这个长方形与Transform t的中心点的距离 public static void ToDrawRectangle2D(Transform t, float distance, float length, float width){ LineRenderer lr = GetLineRenderer(t); lr.positionCount = 5; if (IsFacingRight(t)) { Vector2 forwardMiddle = new Vector2(t.position.x + distance, t.position.y); lr.SetPosition(0, forwardMiddle + new Vector2(0, width / 2)); lr.SetPosition(1, forwardMiddle + new Vector2(length, width / 2)); lr.SetPosition(2, forwardMiddle + new Vector2(length, -width / 2)); lr.SetPosition(3, forwardMiddle + new Vector2(0, -width / 2)); lr.SetPosition(4, forwardMiddle + new Vector2(0, width / 2)); } else { Vector2 forwardMiddle = new Vector2(t.position.x - distance, t.position.y); lr.SetPosition(0, forwardMiddle + new Vector2(0, width / 2)); lr.SetPosition(1, forwardMiddle + new Vector2(-length, width / 2)); lr.SetPosition(2, forwardMiddle + new Vector2(-length, -width / 2)); lr.SetPosition(3, forwardMiddle + new Vector2(0, -width / 2)); lr.SetPosition(4, forwardMiddle + new Vector2(0, width / 2)); } } public static bool IsFacingRight(Transform t){ if (t.localEulerAngles.y > 0) return false; else return true; }}
6、脚本编译正确，回到Unity界面，把脚本赋给 Cube，具体如下图
7、运行场景，然后按下 A 键，2D游戏的矩形范围攻击线绘制出来，具体如下图
8、到此，《Unity 实用教程 之 绘制2D游戏矩形攻击范围线》讲解结束，谢谢
