HTML5（一）layout
1.<canvas> tag
our first example will be test1.html:
<canvas id="tutorial" width="150" height="150" style="background-color:red;">
your browser does not support Canvas tag.
</canvas>
if you are using chrome, you will see a red area with width=150 and height=150.
if you are using other web browsers, you may only see the content 'your browser does not support Canvas tag.'
The detail information about canvas is here: http://www.w3school.com.cn/html5/html5_canvas.asp
2. get render content
var canvas = document.getElementById("turorial");
var ctx = canvas.getContent('2d');
ctx is a CanvasRenderingContext2D object, we can find detail in http://www.w3school.com.cn/htmldom/dom_obj_canvasrenderingcontext2d.asp
3. Supporting from browser
<input type="button" name="Check_Support" value="Check Support" onclick="testCanvas();">
<script type="text/javascript">
function testCanvas(){
var canvas = document.getElementById('tutorial'); // get the canvas object
if (canvas.getContext){ //check if it is supported by the browser
alert("support <canvas> tag");
} else {
alert("not support <canvas> tag");
}
}
</script>
4. my sample codes test1.html:
<canvas id="tutorial" width="150" height="150" style="background-color:red;">
you browser does not support Canvas tag.
</canvas>
<input type="button" name="Check_Support" value="Check Support" onclick="testCanvas();">
<script type="text/javascript">
function testCanvas(){
var canvas = document.getElementById('tutorial');
if (canvas.getContext){
alert("support <canvas> tag");
} else {
alert("not support <canvas> tag");
}
}
</script>
references:
http://www.blogjava.net/myqiao/category/46360.html