[原创]基于html5新标签canvas写的一个小画板

最近刚学了canvas，写个小应用练习下

源代码

 <!DOCTYPE>

 <html>

 <head>

 <meta http-equiv="Content-Type" content="text/html; charset=utf-8" />

 <title>無標題文件</title>

 <script src="http://ajax.googleapis.com/ajax/libs/jquery/1.8.0/jquery.min.js"></script>

 <link rel="stylesheet" href="http://code.jquery.com/mobile/1.3.2/jquery.mobile-1.3.2.min.css">

 <script src="http://code.jquery.com/mobile/1.3.2/jquery.mobile-1.3.2.min.js"></script>

 <script type="text/javascript">

 var drawable=false;

 $(function(){

     $("#drawOnBoard").css({"background-color":$("#backgroundcolorChooser").val()});

 });

 function changeBackgroundColor()

 {

     $("#drawOnBoard").css({"background-color":$("#backgroundcolorChooser").val()});

 }

 function setDrawable(sdrawable)

 {

     drawable=sdrawable;

 }

 function beginDrawPicture(event)

 {

     if(drawable==true)

     {

     var canvas=$("#drawOnBoard");

     canvas=canvas[0];

     var content=canvas.getContext("2d");

     var mouseX=event.clientX;

     var mouseY=event.clientY;

     content.beginPath();

     content.arc(mouseX,mouseY,$("#slider-fill").val()*2,0,Math.PI*2,true);

     content.closePath();

     content.fillStyle=$("#pencolorChooser").val();

     content.fill();

     }

 }

 </script>

 <style type="text/css">

 .chooseBar{

     display:inline-block;

     width:200px;

 }

 div.ui-input-text{

     display:inline-block;

     width:270px;

 }

 div.ui-slider{

     display:inline-block;

     width:300px;

 }

 </style>

 </head>

 <body>

 <canvas id="drawOnBoard" width="600px" height="600px" onmousedown="setDrawable(true);" onMouseMove="beginDrawPicture(event);" onMouseUp="setDrawable(false);" style="border:5px wheat solid;background-color:white;float:left;"></canvas>

 <div style="float:left;margin-top:50px;margin-left:20px;">

 改变画笔颜色：<input type="color" id="pencolorChooser" class="chooseBar"/>

 <br/>

 改变画板颜色：<input type="color" id="backgroundcolorChooser" value="#ffffff" onChange="changeBackgroundColor();" class="chooseBar"/>

 <br/>

 改变画笔大小：<input type="range" name="slider-fill" id="slider-fill" value="5" min="1" max="10" step="1" data-highlight="true" class="chooseBar">

 </div>

 </body>

 </html>

运行效果如图

[原创]基于html5新标签canvas写的一个小画板-LMLPHP

仍然有一些问题：

改变浏览器位置时实际绘画位置和鼠标位置有差

滑鼠走动过快会产生断点

希望学习更多知识以后来改进