Question

下面的代码创建具有比率的全屏图像。但它不适用于与excanvas。我无法解决问题。有什么帮助吗？

这是jsfiddle链接： http://jsfiddle.net/salt/Zs6uV/

    <!DOCTYPE html>
    <html>
      <head>
        <meta charset="utf-8" />
        <title>aspectratio test</title>
<script type="text/javascript">
        function getWindowSize(typ) {
        var myWidth = 0, myHeight = 0;
        if( typeof( window.innerWidth ) == 'number' ) {
          //Non-IE
          myWidth = window.innerWidth;
          myHeight = window.innerHeight;
        } else if( document.documentElement && ( document.documentElement.clientWidth || document.documentElement.clientHeight ) ) {
          //IE 6+ in 'standards compliant mode'
          myWidth = document.documentElement.clientWidth;
          myHeight = document.documentElement.clientHeight;
        } else if( document.body && ( document.body.clientWidth || document.body.clientHeight ) ) {
          //IE 4 compatible
          myWidth = document.body.clientWidth;
          myHeight = document.body.clientHeight;
        }
        if(typ=="width"){
            return myWidth;
        }else{
            return myHeight;
        };
    };
</script>
        <script type="text/javascript" src="http://code.jquery.com/jquery-1.7.1.min.js"></script>
        <!--[if IE]><script type="text/javascript" src="http://explorercanvas.googlecode.com/svn/trunk/excanvas.js"></script><![endif]-->
    <!--[if lt IE 9]><script src="http://html5shim.googlecode.com/svn/trunk/html5.js"></script><![endif]-->
      </head>
      <body style="margin:0px;"  onLoad="setupBackground();">
         <canvas id="myCanvas" style="position:absolute;left: 0px; top: 0px; z-index: 1;"></canvas>
    <script type="text/javascript">
    function setupBackground() {
         canvas = document.getElementById('myCanvas');
        if (typeof window.G_vmlCanvasManager!="undefined") { 
            canvas=window.G_vmlCanvasManager.initElement(canvas);
            var ctx = canvas.getContext('2d');
        }else{
            var ctx = canvas.getContext('2d');
        };
        function draw() {
            canvas.width = 0;
            canvas.height = 0;

            var divWidth = getWindowSize("width"); 
            var divHeight = getWindowSize("height"); 

            var yScale = divHeight / img.height;
            var xScale = divWidth / img.width;

            var newImgHeight = img.height * xScale;
            var newImgWidth = divWidth;

            if (divHeight >= newImgHeight) {
                newImgHeight = divHeight;
                newImgWidth = img.width * yScale;
            };

            canvas.width = divWidth;
            canvas.height = divHeight;

        var diffX =(Math.max(newImgWidth,divWidth)-Math.min(newImgWidth,divWidth))/2;
        var diffY =(Math.max(newImgHeight,divHeight)-Math.min(newImgHeight,divHeight))/2;
        var imgX=0-diffX;
        var imgY=0-diffY;
            ctx.drawImage(img,imgX,imgY,newImgWidth,newImgHeight);
        };

        var img = new Image();
        img.onload = function() {
            $(window).bind('resize', function() {
            draw();
        });
            draw();
        };
        img.src ='http://userserve-ak.last.fm/serve/_/460496/Popperklopper.jpg';
    };
    </script>
    </body>
    </html>

Answer 1

不确定是否是您的问题，但是当您这样做时：

<!--[if IE]><script type="text/javascript" src="http://explorercanvas.googlecode.com/svn/trunk/excanvas.js"></script><![endif]-->
    <!--[if lt IE 9]><script src="http://html5shim.googlecode.com/svn/trunk/html5.js"></script><![endif]-->

应该是：

<!--[if IE]--><script type="text/javascript" src="http://explorercanvas.googlecode.com/svn/trunk/excanvas.js"></script><!--[endif]-->
        <!--[if lt IE 9]--><script src="http://html5shim.googlecode.com/svn/trunk/html5.js"></script><!--[endif]-->

您保持脚本记录，以便它不会在IE版本上工作，希望它能解决您的问题。

纵横比图像调整大小的excanvas错误

1 个答案: