你可以透過多種方法使用Canva繪製路徑,盒、圓、字元以及新增影像。
注意: 預設為
畫方
<span style="color: #008000"><!--</span><span style="color: #008000">fillStyle是填充样式,如果不设置fillStyle属性,默认填充色为黑色,fillRect是画一个矩形,参数为X,Y,Width,Height</span><span style="color: #008000">--></span><span style="color: #0000ff"><!</span><span style="color: #ff00ff">DOCTYPE html</span><span style="color: #0000ff">></span><span style="color: #0000ff"><</span><span style="color: #800000">html</span><span style="color: #0000ff">></span><span style="color: #0000ff"><</span><span style="color: #800000">head</span><span style="color: #0000ff">></span><span style="color: #0000ff"><</span><span style="color: #800000">meta </span><span style="color: #ff0000">charset</span><span style="color: #0000ff">="UTF-8"</span><span style="color: #ff0000"> name</span><span style="color: #0000ff">="author"</span><span style="color: #ff0000"> content</span><span style="color: #0000ff">="赵慧娟"</span><span style="color: #0000ff">></span><span style="color: #0000ff"><</span><span style="color: #800000">title</span><span style="color: #0000ff">></</span><span style="color: #800000">title</span><span style="color: #0000ff">></span><span style="color: #0000ff"><</span><span style="color: #800000">script </span><span style="color: #ff0000">src</span><span style="color: #0000ff">="Scripts/jquery-1.10.2.js?1.1.10"</span><span style="color: #0000ff">></</span><span style="color: #800000">script</span><span style="color: #0000ff">></span><span style="color: #0000ff"><</span><span style="color: #800000">script </span><span style="color: #ff0000">type</span><span style="color: #0000ff">="text/javascript"</span><span style="color: #0000ff">></span><span style="background-color: #f5f5f5; color: #000000">$(</span><span style="background-color: #f5f5f5; color: #0000ff">function</span><span style="background-color: #f5f5f5; color: #000000">(){</span><span style="background-color: #f5f5f5; color: #0000ff">var</span><span style="background-color: #f5f5f5; color: #000000"> canvas</span><span style="background-color: #f5f5f5; color: #000000">=</span><span style="background-color: #f5f5f5; color: #000000">document.getElementById(</span><span style="background-color: #f5f5f5; color: #000000">"</span><span style="background-color: #f5f5f5; color: #000000">myCanvas</span><span style="background-color: #f5f5f5; color: #000000">"</span><span style="background-color: #f5f5f5; color: #000000">)</span><span style="background-color: #f5f5f5; color: #0000ff">var</span><span style="background-color: #f5f5f5; color: #000000"> ctx</span><span style="background-color: #f5f5f5; color: #000000">=</span><span style="background-color: #f5f5f5; color: #000000">canvas.getContext(</span><span style="background-color: #f5f5f5; color: #000000">"</span><span style="background-color: #f5f5f5; color: #000000">2d</span><span style="background-color: #f5f5f5; color: #000000">"</span><span style="background-color: #f5f5f5; color: #000000">); ctx.fillStyle</span><span style="background-color: #f5f5f5; color: #000000">=</span><span style="background-color: #f5f5f5; color: #000000">"</span><span style="background-color: #f5f5f5; color: #000000">deeppink</span><span style="background-color: #f5f5f5; color: #000000">"</span><span style="background-color: #f5f5f5; color: #000000">; ctx.fillRect(</span><span style="background-color: #f5f5f5; color: #000000">10</span><span style="background-color: #f5f5f5; color: #000000">,</span><span style="background-color: #f5f5f5; color: #000000">10</span><span style="background-color: #f5f5f5; color: #000000">,</span><span style="background-color: #f5f5f5; color: #000000">100</span><span style="background-color: #f5f5f5; color: #000000">,</span><span style="background-color: #f5f5f5; color: #000000">100</span><span style="background-color: #f5f5f5; color: #000000">);<br> <span style="color: #339966"> //ctx.moveTo(0,0); //定义开始坐标</span><br><span style="color: #339966"> //ctx.lineTo(100,100); //定义结束坐标</span><br><span style="color: #339966"> //ctx.stroke(); //绘制线条</span><br></span>
})</script></head><body><canvas id="myCanvas" width="100" height="100"></canvas></body></html>
運行結果:
##畫圓
<span style="color: #008000"><!--</span><span style="color: #008000">arc画圆,参数是X,Y,半径,起始角,结束角,顺时针/逆时针(可选)XY指的是圆点的距离</span><span style="color: #008000">--></span><span style="color: #0000ff"><!</span><span style="color: #ff00ff">DOCTYPE html</span><span style="color: #0000ff">></span><span style="color: #0000ff"><</span><span style="color: #800000">html</span><span style="color: #0000ff">></span><span style="color: #0000ff"><</span><span style="color: #800000">head</span><span style="color: #0000ff">></span><span style="color: #0000ff"><</span><span style="color: #800000">meta </span><span style="color: #ff0000">charset</span><span style="color: #0000ff">="UTF-8"</span><span style="color: #ff0000"> name</span><span style="color: #0000ff">="author"</span><span style="color: #ff0000"> content</span><span style="color: #0000ff">="赵慧娟"</span><span style="color: #0000ff">></span><span style="color: #0000ff"><</span><span style="color: #800000">title</span><span style="color: #0000ff">></</span><span style="color: #800000">title</span><span style="color: #0000ff">></span><span style="color: #0000ff"><</span><span style="color: #800000">script </span><span style="color: #ff0000">src</span><span style="color: #0000ff">="Scripts/jquery-1.10.2.js?1.1.10"</span><span style="color: #0000ff">></</span><span style="color: #800000">script</span><span style="color: #0000ff">></span><span style="color: #0000ff"><</span><span style="color: #800000">script </span><span style="color: #ff0000">type</span><span style="color: #0000ff">="text/javascript"</span><span style="color: #0000ff">></span><span style="background-color: #f5f5f5; color: #000000">$(</span><span style="background-color: #f5f5f5; color: #0000ff">function</span><span style="background-color: #f5f5f5; color: #000000">(){</span><span style="background-color: #f5f5f5; color: #0000ff">var</span><span style="background-color: #f5f5f5; color: #000000"> canvas</span><span style="background-color: #f5f5f5; color: #000000">=</span><span style="background-color: #f5f5f5; color: #000000">document.getElementById(</span><span style="background-color: #f5f5f5; color: #000000">"</span><span style="background-color: #f5f5f5; color: #000000">myCanvas</span><span style="background-color: #f5f5f5; color: #000000">"</span><span style="background-color: #f5f5f5; color: #000000">)</span><span style="background-color: #f5f5f5; color: #0000ff">var</span><span style="background-color: #f5f5f5; color: #000000"> ctx</span><span style="background-color: #f5f5f5; color: #000000">=</span><span style="background-color: #f5f5f5; color: #000000">canvas.getContext(</span><span style="background-color: #f5f5f5; color: #000000">"</span><span style="background-color: #f5f5f5; color: #000000">2d</span><span style="background-color: #f5f5f5; color: #000000">"</span><span style="background-color: #f5f5f5; color: #000000">); ctx.fillStyle</span><span style="background-color: #f5f5f5; color: #000000">=</span><span style="background-color: #f5f5f5; color: #000000">"</span><span style="background-color: #f5f5f5; color: #000000">deeppink</span><span style="background-color: #f5f5f5; color: #000000">"</span><span style="background-color: #f5f5f5; color: #000000">; ctx.arc(</span><span style="background-color: #f5f5f5; color: #000000">50</span><span style="background-color: #f5f5f5; color: #000000">,</span><span style="background-color: #f5f5f5; color: #000000">50</span><span style="background-color: #f5f5f5; color: #000000">,</span><span style="background-color: #f5f5f5; color: #000000">50</span><span style="background-color: #f5f5f5; color: #000000">,</span><span style="background-color: #f5f5f5; color: #000000">0</span><span style="background-color: #f5f5f5; color: #000000">,</span><span style="background-color: #f5f5f5; color: #000000">2</span><span style="background-color: #f5f5f5; color: #000000">*</span><span style="background-color: #f5f5f5; color: #000000">Math.PI); ctx.stroke();<br><span class="hl-identifier"> <span style="color: #339966">//ctx</span><span class="hl-code"><span style="color: #339966">.</span><span class="hl-identifier"><span style="color: #339966">fillText</span><span class="hl-brackets"><span style="color: #339966">(</span><span class="hl-quotes"><span style="color: #339966">"</span><span class="hl-string"><span style="color: #339966">Hello World</span><span class="hl-quotes"><span style="color: #339966">"</span><span class="hl-code"><span style="color: #339966">,</span><span class="hl-number"><span style="color: #339966">10</span><span class="hl-code"><span style="color: #339966">,</span><span class="hl-number"><span style="color: #339966">50</span><span class="hl-brackets"><span style="color: #339966">)</span><span class="hl-code"><span style="color: #339966">; //绘制实心字体</span><br><span style="color: #339966"> //<span class="hl-identifier">ctx<span class="hl-code">.<span class="hl-identifier">strokeText<span class="hl-brackets">(<span class="hl-quotes">"<span class="hl-string">Hello World<span class="hl-quotes">"<span class="hl-code">,<span class="hl-number">10<span class="hl-code">,<span class="hl-number">50<span class="hl-brackets">)<span class="hl-code">; //绘制空心字体</span></span></span></span></span></span></span></span></span></span></span></span></span></span><br></span></span></span></span></span></span></span></span></span></span></span></span></span>})</span><span style="color: #0000ff"></</span><span style="color: #800000">script</span><span style="color: #0000ff">></span><span style="color: #0000ff"><</span><span style="color: #800000">style </span><span style="color: #ff0000">type</span><span style="color: #0000ff">="text/css"</span><span style="color: #0000ff">></span><span style="background-color: #f5f5f5; color: #800000">canvas</span><span style="background-color: #f5f5f5; color: #000000">{</span><span style="background-color: #f5f5f5; color: #ff0000">border</span><span style="background-color: #f5f5f5; color: #000000">:</span><span style="background-color: #f5f5f5; color: #0000ff"> 1px solid #000</span><span style="background-color: #f5f5f5; color: #000000">;</span><span style="background-color: #f5f5f5; color: #000000">}</span><span style="color: #0000ff"></</span><span style="color: #800000">style</span><span style="color: #0000ff">></span><span style="color: #0000ff"></</span><span style="color: #800000">head</span><span style="color: #0000ff">></span><span style="color: #0000ff"><</span><span style="color: #800000">body</span><span style="color: #0000ff">></span><span style="color: #0000ff"><</span><span style="color: #800000">canvas </span><span style="color: #ff0000">id</span><span style="color: #0000ff">="myCanvas"</span><span style="color: #ff0000"> width</span><span style="color: #0000ff">="100"</span><span style="color: #ff0000"> height</span><span style="color: #0000ff">="100"</span><span style="color: #0000ff">></</span><span style="color: #800000">canvas</span><span style="color: #0000ff">></span><span style="color: #0000ff"></</span><span style="color: #800000">body</span><span style="color: #0000ff">></span><span style="color: #0000ff"></</span><span style="color: #800000">html</span><span style="color: #0000ff">></span>運行結果:
漸層
createLinearGradient(x,y,x1,y1) - 建立線條漸層
createRadialGradient(x,y,r,x1,y1,r1) - 建立一個徑向/圓漸層
// 创建渐变var grd=ctx.createLinearGradient(0,0,200,0); grd.addColorStop(0,"red"); grd.addColorStop(1,"blue"); // 填充渐变ctx.fillStyle=grd; ctx.fillRect(10,10,150,80);運行結果:
徑向/圓漸層
#var c=document.getElementById("myCanvas"); var ctx=c.getContext("2d"); // 创建渐变 var grd=ctx.createRadialGradient(75,50,5,90,60,100); grd.addColorStop(0,"red"); grd.addColorStop(1,"white"); // 填充渐变 ctx.fillStyle=grd; ctx.fillRect(10,10,150,80);運行結果:
圖片
#<!DOCTYPE html><html><head><meta charset="UTF-8" name="author" content="赵慧娟"><title></title><script src="Scripts/jquery-1.10.2.js?1.1.10"></script><style type="text/css">canvas{border: 1px solid #000;}#flower{border: 1px solid #000;width: 100px;height: 100px;}</style></head><body><img src="img/a.ico" id="flower" /><canvas id="myCanvas" width="100" height="100"></canvas><script type="text/javascript">$(function(){var canvas=document.getElementById("myCanvas")var ctx=canvas.getContext("2d");var img=document.getElementById("flower"); img.onload=function(){ ctx.drawImage(img,20,20,80,80); //drawImage(对象,X,Y,W,H)} })</script></body></html>運行結果:
(右圖為canvas圖像)
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