根据点击触摸画线

代码中有一个物体是拥有Linedrend组件的，自行设置

using System.Collections;

using System.Collections.Generic;

using UnityEngine;

using UnityEngine.UI;

using UnityEngine.EventSystems;

using System;

public class TouchListener : MonoBehaviour, IPointerDownHandler, IPointerExitHandler

{

    private Image image;

    public Text text;

    private bool isEnter = false;

    private bool isSlider = false;

    //带有LineRender物体

    public GameObject target;

    public void OnPointerDown(PointerEventData eventData)

    {

        if (isEnter == false)

            isEnter = true;

    }

    public void OnPointerExit(PointerEventData eventData)

    {

        if (isSlider == true)

        {

            isEnter = false;

            isSlider = false;

            int count = Convert.ToInt32(text.text) + 1;

            if (count >= 10)

                return;

            text.text = count.ToString();

            StartCoroutine(DeleteLine());

        }

    }

    void Start()

    {

        image = GetComponent<Image>();

        text = UnityHelp.GettheChildNodeComponentScripts<Text>(this.gameObject, "Text");

        target = GameObject.Find("GameObject");

    }

    private LineRenderer line;

    int i = 0;

    // Update is called once per frame

    void Update()

    {

        //if (isEnter && Input.touchCount > 0 && Input.GetTouch(0).phase == TouchPhase.Moved)

        if (isEnter && Input.GetMouseButton(0))

        {

            isSlider = true;

            line = target.GetComponent<LineRenderer>();

            line.startColor = Color.white;

            line.endColor = Color.white;

            line.startWidth = 0.5f;

            line.endWidth = 0.5f;

            i++;

            // 设置顶点数

            line.positionCount = i;

            //设置顶点位置(顶点的索引，将鼠标点击的屏幕坐标转换为世界坐标)

            //line.SetPosition(i - 1, Camera.main.ScreenToWorldPoint(new Vector3(Input.GetTouch(0).position.x, Input.GetTouch(0).position.y, 15)));

            line.SetPosition(i - 1, Camera.main.ScreenToWorldPoint(new Vector3(Input.mousePosition.x, Input.mousePosition.y, 15)));

        }

    }

    IEnumerator DeleteLine()

    {

        yield return new WaitForSeconds(2.0f);

        line.positionCount = 0;

        i = 0;

    }

}