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1、&t;canvas></canvas>是HTML5中新增的标签，用于绘制图形，这篇文章主要 为大家详细介绍了HTML5 canvas基本绘图之绘制线条方法，感兴趣的小伙伴们可以参考一下&t;canvas></canvas>是HTML5中新增的标签，用于绘制图形，实际上，这个 标签和其他的标签一样，其特殊之处在于该标签可以获取一个CanvasRenderingContext2D对象，我们可以通过 JavaScript脚本来控制该对象进行绘图。&t;canvas></canvas>只是一个绘制图形的容器， 除了 id、class、style 等
2、属性外， 还有height和width属性。在 &t;canvas>>元素上绘图主要有三步：1. 获取<canvas>元素对应的 DOM 对象，这是一个 Canvas对象；2. 调用 Canvas 对象的 getContext()方法，得到一个 CanvasRenderingContext2D 对象；3. 调用 CanvasRenderingContext2D 对象进行绘图。线条属性除了上面用到的lineWidth属性，线条还有以下几个属性：&n bsp; li neCap属性设置或返回线条末端线帽的样式，可以取以下几个值：&n bsp;“ butt”向线条的每个末端添
3、加平直的边缘(默认) ； “ rou nd ”向线条的每个末端添加圆形线帽；&n bsp;“ square”向线条的每个末端添加正方形线帽。&n bsp; l in eJoin 属性当两条线交汇时设置或返回所创建边角的类型，可以取以 下几个值：&n bsp;“ miter” 创建尖角(默认)； “ bevel” 创建斜角；&n bsp;“ rou nd ”创建圆角。 miterLimit 属性设置或返回最大斜接长度(默认为 10)。斜接长度指的 是在两条线交汇处内角和外角之间的距离。只有当lineJoin属性为“ miter”时，miterLimit才有效。&n
4、bsp;JavaScript Code复制内容到剪贴板var can vas = docume nt.getEleme ntByld(ca nvas); &n bsp;&n bsp;&n bsp; &n bsp; var con text = can vas.getC on text(2d); &n bsp;&n bsp; / 测试 lineCap 属性 /设置基准线便于观察 &n bsp; &n bsp; con text.moveTo(10,10); &n bsp;&n bsp;&n bsp
5、; &n bsp; con text.li neTo(10,200); &n bsp; &n bsp;&n bsp; &n bsp; con text.moveTo(200,10); &n bsp;&n bsp;&n bsp; &n bsp; con text.li neTo(200,200); &n bsp;&n bsp;&n bsp; &n bsp; con text. lin eWidth=1; &n bsp;&n bsp;&n bsp; &n bsp; con text.stroke(); &n bsp ;&n bsp;&n bsp; &n bsp; /butt &n bsp;&n b
6、sp;&n bsp; &n bsp; con text.begi nPath(); &n bsp ;&n bsp;&n bsp; &n bsp; con text.moveTo(10,50); &n bsp;&n bsp;&n bsp; &n bsp; con text.li neTo(200,50); &n bsp; &n bsp;&n bsp; &n bsp; con text.li neCap=butt; &n bsp ;&n bsp;&n bsp; &n bsp; con text.li neWidth=10; &n bsp;&n bsp;&n bsp; &n bsp; con tex
7、t.stroke(); &n bsp ;&n bsp;&n bsp; &n bsp; /round &n bsp;&n bsp;&n bsp; &n bsp; con text.begi nPath(); &n bsp ;&n bsp;&n bsp; &n bsp; con text.moveTo(10,100); &n bsp;&n bsp; &n bsp; &n bsp; con text.li neTo(200,100); &n bsp;&n bsp;&n bsp; &n bsp; con text.li neCap=ro un d; &n bsp;&n bsp; &n bsp; &n
8、bsp; con text.li neWidth=10; &n bsp;&n bsp;&n bsp; &n bsp; con text.stroke(); &n bsp ;&n bsp;&n bsp; &n bsp; /square &n bsp;&n bsp;&n bsp; &n bsp; con text.begi nPath(); &n bsp ;&n bsp;&n bsp; &n bsp; con text.moveTo(10,150); &n bsp;&n bsp; &n bsp; &n bsp; con text.li neTo(200,150); &n bsp;&n bsp;&n
9、 bsp; &n bsp; con text.li neCap=square; &n bsp ;&n bsp;&n bsp; &n bsp; con text.li neWidth=10; &n bsp;&n bsp;&n bsp; &n bsp; con text.stroke(); &n bsp ;&n bsp; / 测试 linJoin 属性 &n bsp; &n bsp; /miter &n bsp;&n bsp;&n bsp; &n bsp; con text.begi nPath(); &n bsp ;&n bsp;&n bsp;
10、&n bsp; con text.moveTo(300,50); &n bsp;&n bsp;&n bsp; &n bsp; con text.li neTo(450,100); &n bsp;&n bsp;&n bsp; &n bsp; con text.li neTo(300,150); &n bsp;&n bsp; &n bsp; &n bsp; con text.li neJoin= miter; &n bsp;&n bsp;&n bsp; &n bsp; con text.li neWidth=10; &n bsp;&n bsp;&n bsp; &n bsp; con text.st
11、roke(); &n bsp ;&n bsp;&n bsp; &n bsp; /round &n bsp;&n bsp;&n bsp; &n bsp; con text.begi nPath(); &n bsp ;&n bsp;&n bsp; &n bsp; con text.moveTo(400,50); &n bsp;&n bsp;&n bsp; &n bsp; con text.li neTo(550,100); &n bsp;&n bsp;&n bsp; &n bsp; con text.li neTo(400,150); &n bsp;&n bsp;&n bsp; &n bsp; c
12、on text.li neJoin=ro un d; &n bsp;&n bsp; &n bsp; &n bsp; con text.li neWidth=10; &n bsp;&n bsp;&n bsp; &n bsp; con text.stroke(); &n bsp ;&n bsp;&n bsp; &n bsp; /square &n bsp;&n bsp;&n bsp; &n bsp; con text.begi nPath(); &n bsp ;&n bsp;&n bsp; &n bsp; con text.moveTo(500,50); &n bsp;&n bsp;&n bsp;
13、 &n bsp; con text.li neTo(650,100); &n bsp;&n bsp;&n bsp; &n bsp; con text.li neTo(500,150); &n bsp;&n bsp;&n bsp; &n bsp; con text.li neJoin=bevel; &n bsp ;&n bsp; &n bsp; &n bsp; con text.li neWidth=10; &n bsp;&n bsp;&n bsp; &n bsp; con text.stroke(); &n bsp ;&n bsp; / 测试 miterLimit 属
14、性 &n bsp; &n bsp; con text.begi nPath(); &n bsp ;&n bsp;&n bsp; &n bsp; con text.moveTo(700,50); &n bsp;&n bsp;&n bsp; &n bsp; con text.li neTo(850,100); &n bsp;&n bsp;&n bsp; &n bsp; con text.li neTo(700,150); &n bsp;&n bsp;&n bsp; &n bsp; con text.li neJoin= miter; &n bsp;&n bsp;&n bsp; &n bsp; con text.miterLimit=2; &n bsp;&n bsp;&n bsp; &n bsp; con text.li neWidth=10; &n bsp;&n bsp;&n bsp; &n bsp; con text.strokeStyle=#2913EC; &n bsp;&n bsp;&n bsp; &n bsp; con text.stroke(); &n bsp ;&n bsp;各属性的不同取值的效果如下：以上就是本文的全部内容，希望对大家的学习有所帮助
