如何让js funtion运行一次？ [英] How should I make js funtion run once?

问题描述

我需要在2个盒子之间绘制一条线，但只需要一次，每当我再次点击时，我看到线条变得越来越厚。我真的需要执行它一次，因为我需要将它保存到数据库，我不想要冗余数据，如果它在执行时一直保存/绘图。



var try1 = true

window.addEventListener（keydown，check，false&& try1 == true）;

function check（key）{

if（key.keyCode ==65）{





c.beginPath（）;

c.moveTo（150,150）;

c.lineTo（300,150）;

c.strokeStyle =red;

c.stroke（）;

try1 = false;

}}



我尝试了什么：



我在链接中尝试了什么，并尝试使用af进行循环。我很遗憾没有成功!!!

I need to draw a line between 2 boxes, but only once, whenever i click again, i see the line is getting thicker and thicker. I really need to execute it once cause later on I need to save it to a db, and I dont want redundant data, if it keeps saving/drawing when its executed.

var try1 = true
window.addEventListener("keydown",check,false && try1 ==true);
function check(key) {
if (key.keyCode == "65") {


c.beginPath();
c.moveTo(150,150);
c.lineTo(300,150);
c.strokeStyle ="red";
c.stroke();
try1 = false;
}}

What I have tried:

I tried whats in the link, and tried to use af for loop. I sadly didnt succeed yet!!!

推荐答案

检查方法中的try1检查

Put the "try1" check in the check method

var try1 = true
window.addEventListener("keydown",check);
function check(key) {
if (try1 == true && key.keyCode == "65") {

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