Html 自动边距元素Enigma的偏移-如何检索x&;来自画布元素的y-鼠标事件
我尝试了除解决方案之外的所有方法,同时试图找出为什么我无法正确地检索位于自动水平边距页面中心的画布上鼠标按下事件的x和y位置 目前:Html 自动边距元素Enigma的偏移-如何检索x&;来自画布元素的y-鼠标事件,html,canvas,Html,Canvas,我尝试了除解决方案之外的所有方法,同时试图找出为什么我无法正确地检索位于自动水平边距页面中心的画布上鼠标按下事件的x和y位置 目前: 我在画布的包含父对象以及 对于画布本身 我正在从鼠标中减去左偏移和顶部偏移 events.pageX和.pageY 我的目标是返回用户将strokeRect拖到画布上的位置(鼠标向下)。我认为这是一个css问题,但我被难住了 body, header, aside, footer, div, canvas{ display: block; po
- 我在画布的包含父对象以及 对于画布本身
- 我正在从鼠标中减去左偏移和顶部偏移 events.pageX和.pageY
body, header, aside, footer, div, canvas{
display: block;
position: relative;
}
canvas {
z-index: 99;
background: #996;
}
#canvas-contain{
height: 600px;
width: 967px;
margin: 50px auto;
box-shadow: 0px 0px 5px 1px #222222;
}
<script>
rect.startX = e.pageX - this.offsetLeft;
rect.startY = e.pageY - this.offsetTop;
function mouseMove(e) {
if (drag) {
rect.w = (e.pageX - this.offsetLeft) - rect.startX;
rect.h = (e.pageY - this.offsetTop) - rect.startY ;
context.clearRect(0,0,canvas.width,canvas.height);
draw();
}
}
function draw() {
context.strokeRect(rect.startX, rect.startY, rect.w, rect.h);
}
</script>
<body>
<div id="ramRod">
<div id="canvas-contain">
<canvas id="canvas" height="600" width="967"></canvas>
</div>
<footer id="footer">
<div id="left-fb" class="foot-box"></div>
<div id="right-fb" class="foot-box"></div>
</footer>
</div>
</body>
正文、页眉、旁白、页脚、div、画布{
显示:块;
位置:相对位置;
}
帆布{
z指数:99;
背景:#996;
}
#画布包含{
高度:600px;
宽度:967px;
保证金:50px自动;
盒影:0px 0px 5px 1px#22222;
}
rect.startX=e.pageX-this.offsetLeft;
rect.startY=e.pageY-this.offsetTop;
函数mouseMove(e){
如果(拖动){
rect.w=(e.pageX-this.offsetLeft)-rect.startX;
rect.h=(e.pageY-this.offsetTop)-rect.startY;
clearRect(0,0,canvas.width,canvas.height);
draw();
}
}
函数绘图(){
strokeRect(rect.startX、rect.startY、rect.w、rect.h);
}
以下是如何在画布上跟踪鼠标事件
在代码中,您需要使用e.clientX/e.clientY而不是e.pageX/e.pageY
…还有小提琴:
正文{背景色:象牙;}
画布{边框:1px纯红;}
$(函数(){
var canvas=document.getElementById(“canvas”);
var ctx=canvas.getContext(“2d”);
var canvasOffset=$(“#画布”).offset();
var offsetX=canvasOffset.left;
var offsetY=canvasOffset.top;
功能手柄向下(e){
canMouseX=parseInt(e.clientX-offsetX);
canMouseY=parseInt(e.clientY-offsetY);
$(“#downlog”).html(“Down:“+canMouseX+”/“+canMouseY”);
//把你的鼠标下的东西放在这里
}
功能handleMouseUp(e){
canMouseX=parseInt(e.clientX-offsetX);
canMouseY=parseInt(e.clientY-offsetY);
$(“#uplog”).html(“Up:“+canMouseX+”/“+canMouseY”);
//把你的鼠标放在这里
}
函数handleMouseOut(e){
canMouseX=parseInt(e.clientX-offsetX);
canMouseY=parseInt(e.clientY-offsetY);
$(“#outlog”).html(“Out:+canMouseX+”/“+canMouseY);
//把你的老鼠屎放在这里
}
功能手柄移动(e){
canMouseX=parseInt(e.clientX-offsetX);
canMouseY=parseInt(e.clientY-offsetY);
$(“#movelog”).html(“移动:+canMouseX+”/“+canMouseY”);
//把你的mousemove放在这里
}
$(“#canvas”).mousedown(函数(e){handleMouseDown(e);});
$(“#canvas”).mousemove(函数(e){handleMouseMove(e);});
$(“#canvas”).mouseup(函数(e){handleMouseUp(e);});
$(“#canvas”).mouseout(函数(e){handleMouseOut(e);});
}); // end$(函数(){});
向下
移动
向上
退出
Hi Five。谢谢clientX,现在我知道了。顺便说一句,你的小提琴棒极了——谢谢你为每一个活动提供了高质量的演示。
<!doctype html>
<html>
<head>
<link rel="stylesheet" type="text/css" media="all" href="css/reset.css" /> <!-- reset css -->
<script type="text/javascript" src="http://code.jquery.com/jquery.min.js"></script>
<style>
body{ background-color: ivory; }
canvas{border:1px solid red;}
</style>
<script>
$(function(){
var canvas=document.getElementById("canvas");
var ctx=canvas.getContext("2d");
var canvasOffset=$("#canvas").offset();
var offsetX=canvasOffset.left;
var offsetY=canvasOffset.top;
function handleMouseDown(e){
canMouseX=parseInt(e.clientX-offsetX);
canMouseY=parseInt(e.clientY-offsetY);
$("#downlog").html("Down: "+ canMouseX + " / " + canMouseY);
// Put your mousedown stuff here
}
function handleMouseUp(e){
canMouseX=parseInt(e.clientX-offsetX);
canMouseY=parseInt(e.clientY-offsetY);
$("#uplog").html("Up: "+ canMouseX + " / " + canMouseY);
// Put your mouseup stuff here
}
function handleMouseOut(e){
canMouseX=parseInt(e.clientX-offsetX);
canMouseY=parseInt(e.clientY-offsetY);
$("#outlog").html("Out: "+ canMouseX + " / " + canMouseY);
// Put your mouseOut stuff here
}
function handleMouseMove(e){
canMouseX=parseInt(e.clientX-offsetX);
canMouseY=parseInt(e.clientY-offsetY);
$("#movelog").html("Move: "+ canMouseX + " / " + canMouseY);
// Put your mousemove stuff here
}
$("#canvas").mousedown(function(e){handleMouseDown(e);});
$("#canvas").mousemove(function(e){handleMouseMove(e);});
$("#canvas").mouseup(function(e){handleMouseUp(e);});
$("#canvas").mouseout(function(e){handleMouseOut(e);});
}); // end $(function(){});
</script>
</head>
<body>
<p id="downlog">Down</p>
<p id="movelog">Move</p>
<p id="uplog">Up</p>
<p id="outlog">Out</p>
<canvas id="canvas" width=300 height=300></canvas>
</body>
</html>