HTML5 Canvas的文本垂直对齐_H5之家 - 中国HTML5教程资源分享第一站

HTML画布垂直对齐的文本，我们可以使用的textBaseline在画布范围内的属性值。textBaseline可以设置以下值之一：top, hanging, middle, alphabetic, ideographic, and bottom。除非另有规定，textBaseline属性默认为字母。

context.textBaseline=[value];

<!DOCTYPE HTML>
<html>
<head>
<title>html5_canvas_text_baseline</title>
<style>
body {margin: 0px;padding: 0px;}
#myCanvas {border: 1px solid #9C9898; margin:0 auto;margin-top:200px; margin-left:100px;}
</style>
<script>
window.onload = function(){
    var canvas = document.getElementById("myCanvas");
    var context = canvas.getContext("2d");

    var x = canvas.width / 2;
    var y = canvas.height / 2;
    context.font = "30pt Calibri";
    // textAlign aligns text horizontally relative to placement
    context.textAlign = "center";
    // textBaseline aligns text vertically relative to font style
    context.textBaseline = "middle";
    context.fillStyle = "blue";
    context.fillText("Hello World!", x, y);
};
</script>
</head>
<body>
<canvas id="myCanvas" width="578" height="200">
</canvas>
</body>
</html>