LineRenderer实现一个画线组件

 using System;

 using UnityEngine;

 class UILine

 {

     GameObject targetObj;

     LineRenderer lineRenderer;      //LineRenderer渲染出的线段的两个端点是3D世界中的点

     int index = ;

     int poinCount = ;  //线段的端点数

     Vector3 position;

     public void Start(GameObject go, Color beginColor, Color endColor, float begineWidth, float endWidth)

     {

         targetObj = go;

         if (null != targetObj)

         {

             targetObj.SetActive(true);

             lineRenderer = targetObj.GetComponent<LineRenderer>();

             if (null == lineRenderer)

                 lineRenderer = targetObj.AddComponent<LineRenderer>();

         }

         if (null != lineRenderer)

         {

             //颜色

             lineRenderer.startColor = beginColor;

             lineRenderer.endColor = endColor;

             //宽度

             lineRenderer.startWidth = begineWidth;

             lineRenderer.endWidth = endWidth;

         }

         index = poinCount = ;

     }

     public void Update()

     {

         if (Input.GetMouseButton())

         {

             //屏幕坐标转换为世界坐标

             position = Camera.main.ScreenToWorldPoint(new Vector3(Input.mousePosition.x, Input.mousePosition.y, 1.0f));

             //端点数+1

             poinCount++;

             //设置线段的端点数

             lineRenderer.positionCount = poinCount;

             //连续绘制线段

             while (index < poinCount)

             {

                 //两点确定一条直线，所以我们依次绘制点就可以形成线段了

                 lineRenderer.SetPosition(index, position);

                 index++;

             }

         }

     }

     public static UILine BeginLine(GameObject go, Color beginColor, Color endColor, float beginWidth, float endWidth)

     {

         UILine line = new UILine();

         line.Start(go, beginColor, endColor, beginWidth, endWidth);

         return line;

     }

 }