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  • html5 canvas 奇怪的形状垂直渐变

    <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
    <html xmlns="http://www.w3.org/1999/xhtml">
    <head>
    <meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
    <title>填充渐变形状</title>
    <script src="js/modernizr.js"></script>
    </head>
    
    <body>
    <script type="text/javascript">
    window.addEventListener('load',eventWindowLoaded,false);
    function eventWindowLoaded(){
        canvasApp();
    }
    function canvasSupport(){
        return Modernizr.canvas;
    }
    function canvasApp(){
        if(!canvasSupport()){
            return;
        }else{
            var theCanvas = document.getElementById('canvas')
            var context = theCanvas.getContext("2d")
    
        }
        drawScreen();
        function drawScreen(){
            //水平渐变值必须保持为0
            var gr = context.createLinearGradient(0,0,0,100);
            //添加颜色端点
            gr.addColorStop(0,'rgb(255,0,0)');
            gr.addColorStop(.5,'rgb(0,255,0)');    
            gr.addColorStop(1,'rgb(0,0,255)');        
            //应用fillStyle生成渐变
            context.fillStyle = gr;
            context.beginPath();
            context.moveTo(0,0);
            context.lineTo(50,0);
            context.lineTo(100,50);
            context.lineTo(50,100);
            context.lineTo(0,100);
            context.lineTo(0,0);
            context.stroke();
            context.fill();
            context.closePath();
            
        
        }
    }
    $(document).ready(function(e) {
        
    });
    
    </script>
    <canvas id="canvas" width="500" height="500">
    你的浏览器无法使用canvas
    小白童鞋;你的支持是我最大的快乐!!
    </canvas>
    </body>
    </html>

    水平渐变无非就是createLinearGradient(0,0,100,0)

    垂直渐变无非就是createLinearGradient(0,0,0,100)

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  • 原文地址:https://www.cnblogs.com/LoveOrHate/p/4428166.html
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