tryhtml5_canvas_measuretext 在线代码实例

 <canvas id="myCanvas" width="300" height="150" style="border:1px solid #d3d3d3;">
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</canvas>
<script>
var c=document.getElementById("myCanvas");
var ctx=c.getContext("2d");
ctx.font="30px Arial";
var txt="Hello World"
ctx.fillText("width:" + ctx.measureText(txt).width,10,50);
ctx.fillText(txt,10,100);
</script>