小编Rya*_*ley的帖子

我最近一直在学习 HTML 画布，并制作了一个在桌面上完美运行的简单绘图应用程序。但在移动设备上我无法绘制连续的线，只能绘制单个点。知道我做错了什么吗？链接到我的 codepen 版本

https://codepen.io/ryan-rigley/pen/oNXEvwm?fbclid=IwAR0rekoc1wcT2d4of0vCW32F0bzQDX1kW8DsJKiDq8t0ymLky1IkHyu8ozc

let color = "black";
let strokeSize = 10;

function changeColorAndSize(data, width) {
  color = data;
  strokeSize = width;
}
window.addEventListener("load", () => {
  const canvas = document.querySelector("#canvas");
  const ctx = canvas.getContext("2d");

  //resizing
  canvas.height = window.innerHeight;
  canvas.width = window.innerWidth;

  //variables
  let painting = false;

  //functions
  function startPosition(e) {
    painting = true;
    draw(e);
  }

  function endPosition() {
    painting = false;
    ctx.beginPath();
  }

  function draw(e) {
    if (!painting) {
      return;
    }
    e.preventDefault();
    ctx.lineWidth = strokeSize;
    ctx.lineCap = …