HTML5 Canvas 填充与描边(Fill And Stroke)

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

 

// global variable 2d context
var ctx = null; 
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.");
        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);
}
 

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