HTML5 Canvas 填充与描边(Fill And Stroke)
演示HTML5 Canvas Fill 与Stroke文字效果，基于Canvas如何实
现纹理填充与描边。
一：颜色填充与描边
颜色填充可以通过fillStyle来实现，描边颜色可以通过strokeStyle来实现。简单示例
如下：
// fill and stroke text
ctx.font = '60pt Calibri';
ctx.lineWidth = 3;
ctx.strokeStyle = 'green';
ctx.strokeText('Hello World!', 20, 100);
ctx.fillStyle = 'red';
ctx.fillText('Hello World!', 20, 100);
二：纹理填充与描边
HTML5 Canvas还支持纹理填充，通过加载一张纹理图像，然后创建画笔模式，创建
纹理模式的API为ctx.createPattern(imageTexture,"repeat");第二参数支持四个
值，分别为”repeat-x”, ”repeat-y”, ”repeat”,”no-repeat”意思是纹理分别沿着
X轴，Y轴，XY方向沿重复或者不重复。纹理描边与填充的代码如下：
var woodfill = ctx.createPattern(imageTexture,"repeat");
ctx.strokeStyle = woodfill;
ctx.strokeText('Hello World!', 20, 200);
// fill rectangle
ctx.fillStyle = woodfill;
ctx.fillRect(60, 240, 260, 440);
纹理图片：
三：运行效果
代码：
<!DOCTYPE html> <html> <head> <meta http-equiv="X-UA-Compatible" content="chrome=IE8"> <meta http-equiv="Content-type" content="text/html;charset=UTF-8"> <title>Canvas Fill And Stroke Text Demo</title> <link href="default.css" rel="stylesheet" /> <script> var ctx = null; // global variable 2d context var imageTexture = null; window.onload = function() { var canvas = document.getElementById("text_canvas"); console.log(canvas.parentNode.clientWidth); canvas.width = canvas.parentNode.clientWidth; canvas.height = canvas.parentNode.clientHeight; if (!canvas.getContext) { console.log("Canvas not supported. Please install a HTML5 compatible browser."); return; } // get 2D context of canvas and draw rectangel ctx = canvas.getContext("2d"); ctx.fillStyle="black"; ctx.fillRect(0, 0, canvas.width, canvas.height); // fill and stroke text ctx.font = '60pt Calibri'; ctx.lineWidth = 3; ctx.strokeStyle = 'green'; ctx.strokeText('Hello World!', 20, 100); ctx.fillStyle = 'red'; ctx.fillText('Hello World!', 20, 100); // fill and stroke by pattern imageTexture = document.createElement('img'); imageTexture.src = "../pattern.png"; imageTexture.onload = loaded(); } function loaded() { // delay to image loaded setTimeout(textureFill, 1000/30); } function textureFill() { // var woodfill = ctx.createPattern(imageTexture, "repeat-x"); // var woodfill = ctx.createPattern(imageTexture, "repeat-y"); // var woodfill = ctx.createPattern(imageTexture, "no-repeat"); var woodfill = ctx.createPattern(imageTexture, "repeat"); ctx.strokeStyle = woodfill; ctx.strokeText('Hello World!', 20, 200); // fill rectangle ctx.fillStyle = woodfill; ctx.fillRect(60, 240, 260, 440); } </script> </head> <body> <h1>HTML5 Canvas Text Demo - By Gloomy Fish</h1> <pre>Fill And Stroke</pre> <div id="my_painter"> <canvas id="text_canvas"></canvas> </div> </body> </html>
