前段时间看了某个平台的后台，发现订单显示使用的canvas进行绘画，直观，明了的表达出了订单的走势如下
所以自己心痒痒的，就自己模仿了一个-->贴上代码
<style>
#canvasmain{position: relative;width: 1000px;height: 500px;}
#canvas{position: absolute;top: 0;left: 0;}
#canvassub{position: absolute}
#tip{position: absolute;min-width: 50px;max-width: 70px;background-color: rgba(0, 0, 0, 0.77);color: #fff;text-align: center;border-radius: 6px;-webkit-border-radius: 6px;-moz-border-radius: 6px;pointer-events: none;}
#a,#b{cursor:pointer;}
</style>
<div id="canvasmain">
<canvas id="canvas">
你的浏览器居然不支持Canvas？！赶快换一个吧！！
</canvas>
<canvas id="canvassub"></canvas>
<div id="tip"></div>
</div>
<div>
<p id="line">折线图</p>
<p id="bar">条形图</p>
</div>
<script>
function createCanvas() {
var canvas = document.getElementById("canvas");
canvas.width = 1000;
canvas.height = 500;
var context = canvas.getContext("2d");
if (!canvas.getContext)
return;
this.json = [
{ key: 1, "number": 0 },
{ key: 2, "number": 14 },
{ key: 3, "number": 25 },
{ key: 4, "number": 1 },
{ key: 5, "number": 98 },
{ key: 6, "number": 11 },
{ key: 7, "number": 21 },
{ key: 8, "number": 32 },
{ key: 9, "number": 23 },
{ key: 10, "number": 36 },
{ key: 11, "number": 1 },
{ key: 12, "number": 52 },
{ key: 13, "number": 65 },
{ key: 14, "number": 45 },
{ key: 15, "number": 86 },
{ key: 16, "number": 10 },
{ key: 17, "number": 45 },
{ key: 18, "number": 54 },
{ key: 19, "number": 35 },
{ key: 20, "number": 10 },
{ key: 21, "number": 64 },
{ key: 22, "number": 45 },
{ key: 23, "number": 35 },
{ key: 24, "number": 23 },
{ key: 25, "number": 24 },
{ key: 26, "number": 10 },
{ key: 27, "number": 43 },
{ key: 28, "number": 66 },
{ key: 29, "number": 25 },
{ key: 30, "number": 44 },
{ key: 31, "number": 100 }
];
this.arrnumber = [];
this.maxnumber = 0;
this.wframe = 100;
this.hframe = 50;
this.wlocation = canvas.width - 100;
this.hlocation = canvas.height - 100;
this.wlocationAverage = this.wlocation / this.json.length;
this.moduleArrNumber = function (type) {
for (var i = 0, j = this.json.length; i < j; i++) {
this.arrnumber.push(this.json[i].number);
}
if (type === ‘max‘)
return Math.max.apply(null, this.arrnumber);
else
return Math.min.apply(null, this.arrnumber);
}
this.type = ‘line‘;
var canvassub = document.getElementById("canvassub");
canvassub.width = this.wlocation;
canvassub.height = this.hlocation;
var contextsub = canvassub.getContext("2d");
canvassub.style.top = this.hframe + "px";
canvassub.style.left = this.wframe + "px";
if (typeof this.moduleCanvas != ‘function‘) {
createCanvas.prototype.moduleCanvas = function () {
context.fillStyle = "black";
context.font = "30px Arial";
context.textAlign = "left";
context.textBaseline = "alphabetic";
context.fillText("9月份订单", 10, 30);
context.strokeStyle = ‘#9D9D9D‘;
context.lineWidth = 1;
context.font = "italic small-caps bold 14px Arial";
for (var i = 0; (k = i * (this.hlocation / 10)) <= this.hlocation; i++) {
this.moduleArrNumber(‘max‘) > 10 ? (this.moduleArrNumber(‘max‘) > 100 ? (this.moduleArrNumber(‘max‘) > 1000 ? (this.moduleArrNumber(‘max‘) > 1000 ? this.maxnumber = 10000 : this.maxnumber = 1000) : this.maxnumber = 100) : this.maxnumber = 10) : this.maxnumber = 1;
context.beginPath();
context.moveTo(this.wframe, k + this.hframe);
context.lineTo(this.wlocation + this.wframe, k + this.hframe);
context.stroke();
context.textBaseline = "middle";
context.fillText((10 - i) * this.maxnumber, this.wframe - 50, k + this.hframe);
}
for (var j = 0; (k = j * ((this.wlocation - 1) / this.json.length)) <= this.wlocation; j++) {
context.beginPath();
context.moveTo(k + this.wframe, this.hframe);
context.lineTo(k + this.wframe, this.hlocation + this.hframe);
context.stroke();
if (this.json.length > j)
context.textAlign = "center",context.fillText(this.json[j].key, k + (this.wlocationAverage / 2 + this.wframe), this.hlocation + this.hframe + 40);
}
}
}
if (typeof this.lineChart != ‘function‘) {
createCanvas.prototype.lineChart = function () {
this.type = ‘line‘;
context.strokeStyle = ‘red‘;
context.lineWidth = 2;
var tenmaxnumber = this.maxnumber * 10;
for (var i = 0; i < this.json.length; i++) {
context.beginPath();
context.moveTo(i * this.wlocationAverage + (this.wlocationAverage / 2 + this.wframe), (1 - (this.json[i].number / tenmaxnumber)) * this.hlocation + this.hframe);
if (this.json.length > i + 1)
context.lineTo((i + 1) * this.wlocationAverage + (this.wlocationAverage / 2 + this.wframe), (1 - (this.json[i + 1].number / tenmaxnumber)) * this.hlocation + this.hframe);
context.stroke();
context.fillStyle = ‘black‘;
context.textAlign = "center";
context.fillText(this.json[i].number, i * this.wlocationAverage + (this.wlocationAverage / 2 + this.wframe), (1 - (this.json[i].number / tenmaxnumber)) * this.hlocation + this.hframe - 5);
context.beginPath();
context.fillStyle = "green";
context.arc(i * this.wlocationAverage + (this.wlocationAverage / 2 + this.wframe), (1 - (this.json[i].number / tenmaxnumber)) * this.hlocation + this.hframe, 3, 0, 360, false);
context.fill();
context.closePath();
}
}
}
if (typeof this.barChart != ‘function‘) {
createCanvas.prototype.barChart = function () {
this.type = ‘bar‘;
var tenmaxnumber = this.maxnumber * 10;
for (var i = 0; i < this.json.length; i++) {
context.beginPath();
context.fillStyle = "#F00";
context.fillRect(i * this.wlocationAverage + (this.wlocationAverage / 4 + this.wframe), this.hlocation + this.hframe, this.wlocationAverage / 2, -(this.json[i].number / tenmaxnumber) * this.hlocation);
context.closePath();
context.fillStyle = ‘black‘;
context.textAlign = "center";
context.fillText(this.json[i].number, i * this.wlocationAverage + (this.wlocationAverage / 2 + this.wframe), (1 - (this.json[i].number / tenmaxnumber)) * this.hlocation + this.hframe - 5);
}
}
}
if (typeof this.clearRect != ‘function‘) {
createCanvas.prototype.clearRect = function () {
context.clearRect(0, 0, canvas.width, canvas.height);
contextsub.clearRect(0,0,canvassub.width,canvassub.height);
}
}
}
var cc = new createCanvas();
cc.moduleCanvas();
cc.lineChart();
var position = 0, positionchange = 0;
var canvassub = document.getElementById("canvassub");
var contextsub = canvassub.getContext("2d");
var tip = document.getElementById("tip");
document.getElementById("canvassub").onmousemove = function (e) {
var e = e || window.event;
if (e.offsetX > cc.wframe || e.offsetY > cc.hframe) {
positionchange = Math.floor(e.offsetX / cc.wlocationAverage);
tip.style.display = "block";
tip.innerText = ‘今天共有‘ + cc.json[Math.floor(e.offsetX / cc.wlocationAverage)].number + ‘张订单‘;
tip.setAttribute("style", "top:" + (cc.hlocation - (cc.json[Math.floor(e.offsetX / cc.wlocationAverage)].number / (cc.maxnumber * 10)) * cc.hlocation) + "px;left:" + (parseFloat(Math.floor(e.offsetX / cc.wlocationAverage) + 0.5) * cc.wlocationAverage + cc.wframe) + "px;padding: 3px;");
if (cc.type === ‘line‘ && position !== positionchange) {
contextsub.clearRect(0,0,cc.wlocation,cc.hlocation);
contextsub.beginPath();
contextsub.fillStyle = "blue";
contextsub.arc((parseFloat(Math.floor(e.offsetX / cc.wlocationAverage) + 0.5) * cc.wlocationAverage), (cc.hlocation - (cc.json[Math.floor(e.offsetX / cc.wlocationAverage)].number / (cc.maxnumber * 10)) * cc.hlocation), 4, 0, 360, false);
contextsub.fill();
contextsub.closePath();
position = Math.floor(e.offsetX / cc.wlocationAverage);
}
else if (cc.type === ‘bar‘ && position !== positionchange) {
contextsub.clearRect(0, 0, cc.wlocation, cc.hlocation);
contextsub.beginPath();
contextsub.fillStyle = "blue";
contextsub.fillRect((parseFloat(Math.floor(e.offsetX / cc.wlocationAverage) + 0.25) * cc.wlocationAverage), canvassub.height, cc.wlocationAverage * 0.5, -(cc.json[Math.floor(e.offsetX / cc.wlocationAverage)].number / cc.maxnumber / 10) * cc.hlocation);
contextsub.closePath();
position = Math.floor(e.offsetX / cc.wlocationAverage);
}
}
}
document.getElementById("canvassub").onmouseout = function () {
tip.style.display = "none";
}
document.getElementById("line").onclick = function () {
cc.clearRect();
cc.moduleCanvas();
setTimeout(‘cc.lineChart()‘,300);
}
document.getElementById("bar").onclick = function () {
cc.clearRect();
cc.moduleCanvas();
setTimeout(‘cc.barChart()‘, 300);
}
</script>
效果如下
参考教材：http://blog.csdn.net/clh604/article/details/8536059 http://www.w3school.com.cn/tags/html_ref_canvas.asp
注：Internet Explorer 9+, Firefox, Opera, Chrome, 和 Safari 支持 <canvas> 元素. （注意: Internet Explorer 8 及更早 IE 版本的浏览器不支持 <canvas> 元素.）
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时间： 2024-10-11 06:47:43