原生js实现折线图图表效果代码-html代码-BFW代码库

原生js实现折线图图表效果代码

代码语言：html

所属分类：图表

代码描述：原生js实现折线图图表效果代码

下面为部分代码预览，完整代码请点击下载或在bfwstudio webide中打开

<!DOCTYPE html>
<html lang="en" >
<head>
  <meta charset="UTF-8">

<style>
    body {
  margin: 0;
  overflow: hidden;
  background: #152B39;
  font-family: Courier, monospace;
  font-size: 14px;
  color:#ccc; 
}

.wrapper {
  display: block;
  margin: 5em auto;
  border: 1px solid #555;
  width: 700px;
  height: 350px;
  position: relative;
}
p{text-align:center;}
.label {
  height: 1em;
  padding: .3em;
  background: rgba(255, 255, 255, .8);
  position: absolute;
  display: none;
  color:#333;
  
}
</style>
</head>
<body>
<!-- partial:index.partial.html -->
<div class="wrapper">
  <canvas id='c'></canvas>
  <div class="label">text</div>
</div>
<p>Please mouse over the dots</p>
<!-- partial -->
  <script >
      var label = document.querySelector(".label");
var c = document.getElementById("c");
var ctx = c.getContext("2d");
var cw = c.width = 700;
var ch = c.height = 350;
var cx = cw / 2,
  cy = ch / 2;
var rad = Math.PI / 180;
var frames = 0;

ctx.lineWidth = 1;
ctx.strokeStyle = "#999";
ctx.fillStyle = "#ccc";
ctx.font = "14px monospace";

var grd = ctx.createLinearGradient(0, 0, 0, cy);
grd.addColorStop(0, "hsla(167,72%,60%,1)");
grd.addColorStop(1, "hsla(167,72%,60%,0)");

var oData = {
  "2008": 10,
  "2009": 39.9,
  "2010": 17,
  "2011": 30.0,
  "2012": 5.3,
  "2013": 38.4,
  "2014": 15.7,
  "2015": 9.0
};

var valuesRy = [];
var propsRy = [];
for (var prop in oData) {

  valuesRy.push(oData[prop]);
  propsRy.push(prop);
}


var vData = 4;
var hData = valuesRy.length;
var offset = 50.5; //offset chart axis
var chartHeight = ch - 2 * offset;
var chartWidth = cw - 2 * offset;
var t = 1 / 7; // curvature : 0 = no curvature 
var speed = 2; // for the animation

var A = {
  x: offset,
  y: offset
}
var B = {
  x: offset,
  y: offset + chartHeight
}
var C = {
  x: offset + chartWidth,
  y: offset + chartHeight
}

/*
      A  ^
	    |  |  
	    + 25
	    |
	    |
	    |
	    + 25  
      |__|_________________________________  C
      B
*/

// CHART AXIS -------------------------
ctx.beginPath();
ctx.moveTo(A.x, A.y);
ctx.lineTo(B.x, B.y);
ctx.lineTo(C.x, C.y);
ctx.stroke();

// vertical ( A - B )
var aStep = (chartHeight - 50) / (vData);

var Max = Math.ceil(arrayMax(valuesRy) / 10) * 10;
var Min = Math.floor(arrayMin(valuesRy) / 10) * 10;
var aStepValue = (Max - Min) / (vData);
console.log("aStepValue: " + aStepValue); //8 units
var verticalUnit = aStep / aStepValue;

var a = [];
ctx.textAlign = "right";
ctx.textBaseline = "middle";
for (var i = 0; i <= vData; i++) {

  if (i == 0) {
    a[i] = {
      x: A.x,
      y: A.y + 25,
      val: Max
    }
  } else {
    a[i] = {}
    a[i].x = a[i - 1].x;
    a[i].y = a[i - 1].y + aStep;
    a[i].val = a[i - 1].val - aStepValue;
  }
  drawCoords(a[i], 3, 0);
}

//horizontal ( B - C )
var b = [];
ctx.textAlign = "center";
ctx.textBaseline = "hanging";
var bStep = chartWidth / (hData + 1);

for (var i = 0; i < hData; i++) {
  if (i == 0) {
    b[i] = {
      x: B.x + bStep,
      y: B.y,
      val: propsRy[0]
    };
  } else {
    b[i] = {}
    b[i].x = b[i - 1].x + bStep;
    b[i].y = b[i - 1].y;
    b[i].val = propsRy[i]
  }
  drawCoords(b[i], 0, 3)
}

function drawCoords(o, offX, offY) {
  ctx.beginPath();
  ctx.moveTo(o.x - offX, o.y - offY);
  ctx.lineTo(o.x + offX, o.y + offY);
  ctx.stroke();

  ctx.fillText(o.val, o.x - 2 * offX, o.y + 2 * offY);
}
//------------------------------------------.........完整代码请登录后点击上方下载按钮下载查看