基本上我编码的是能够在文本框中键入单词.当按下按钮提交时,该词会被发布到HTML5画布,以便人们可以看到它.我现在要做的是能够在HTML5画布上拖动该单词.我在实现这一点上遇到了一些困难,并且想知道是否有人可以帮我解决这个问题？这是我的代码到目前为止我所做的:
var fname;
var canvas;
var ctx;
var canvasX;
var canvasY;
var mouseIsDown;
function addTitle2() {
canvas = document.getElementById("canvas");
ctx = canvas.getContext("2d");
canvas.addEventListener("mousedown", mouseDown, false);
canvas.addEventListener("mousemove", mouseXY, false);
document.body.addEventListener("mouseup", mouseUp, false);
var fname = document.forms[0].fname.value;
ctx.fillStyle = "black";
ctx.strokeStyle = "black";
ctx.font = "35px Arial";
ctx.fillText(fname, Math.random() * 500, Math.random() * 400);
ctx.stroke();
}
function mouseUp() {
mouseIsDown = 0;
mouseXY();
}
function mouseDown() {
mouseIsDown = 1;
mouseXY();
}
function mouseXY(e) {
e.preventDefault();
canvasX = e.pageX - canvas.offsetLeft;
canvasY …我想知道如何使用setInterval和clearInterval在javascript中停止计时器十秒后？这是我的代码示例,请你告诉我哪里出错了:
<!DOCTYPE html>
<html>
<head>
<script>
var tt=setInterval(function(){startTime()},1000);
function startTime()
{
var today = new Date();
var h=today.getHours();
var m=today.getMinutes();
var s=today.getSeconds();
// add a zero in front of numbers<10
m=checkTime(m);
s=checkTime(s);
today=checkTime(today);
document.getElementById('txt').innerHTML=s;
}
function checkTime(tt)
{
if (tt==10)
{
tt="0" + tt;
console.log(tt);
clearInterval(tt);
}
return tt;
}
</script>
</head>
<body onload="startTime()">
<div id="txt"></div>
</body>
</html>