目录:
预期效果(静态图演示效果)编辑
2.实现思路
用户可直接用 JS 代码来制作动态背景。
3.实现步骤
1.1新建决策报表,添加body初始化后事件.
JS代码如下:
$("body").prepend('<canvas id="canvas" style="position:absolute;z-index:-2;"></canvas>');
//在body中插入canvas画布,并置于底层
var canvas = document.getElementById('canvas');
var ctx = canvas.getContext('2d');
canvas.width = canvas.parentNode.offsetWidth;
canvas.height = canvas.parentNode.offsetHeight;
//如果浏览器支持requestAnimFrame则使用requestAnimFrame否则使用setTimeout
window.requestAnimFrame = (function(){
return window.requestAnimationFrame ||
window.webkitRequestAnimationFrame ||
window.mozRequestAnimationFrame ||
function( callback ){
window.setTimeout(callback, 1000 / 60);
};
})();
//初始角度为0
var step = 0;
//定义三条不同波浪的颜色
var lines = ["rgba(0,222,255, 0.2)",
"rgba(157,192,249, 0.2)",
"rgba(0,168,255, 0.2)"];
function loop(){
ctx.clearRect(0,0,canvas.width,canvas.height);
step++;
//画3个不同颜色的矩形
for(var j = lines.length - 1; j >= 0; j--) {
ctx.fillStyle = lines[j];
//每个矩形的角度都不同,每个之间相差45度
var angle = (step+j*45)*Math.PI/180;
var deltaHeight = Math.sin(angle) * 50;
var deltaHeightRight = Math.cos(angle) * 50;
ctx.beginPath(); -
ctx.moveTo(0, canvas.height/2+deltaHeight);
ctx.bezierCurveTo(canvas.width /2, canvas.height/2+deltaHeight-50, canvas.width / 2, canvas.height/2+deltaHeightRight-50, canvas.width, canvas.height/2+deltaHeightRight);
ctx.lineTo(canvas.width, canvas.height);
ctx.lineTo(0, canvas.height);
ctx.lineTo(0, canvas.height/2+deltaHeight);
ctx.closePath();
ctx.fill();
}
requestAnimFrame(loop);
}
loop();