JavaScript runtime error: Unspecified error

Question

我的要求是return数据URL。但是，当我运行申请的时候，出现了运行时的错误：

JavaScript runtime error: Unspecified error.

这是我用过的代码。临时路径是图像位置所在的路径。

var canvas = document.createElement("canvas");   
var context = canvas.getContext("2d");         
var img = new Image();         
img.src = "@tempPath";                 
context.drawImage(img, 40, 40);         
var dataURL = canvas.toDataURL("image/jpeg");         
alert(dataURL);'

Answer 1

试试下面的代码，它对我有用：

<body>
    <canvas id="myCanvas"></canvas>
    <img id="profileImg" alt=""/>
    <script src="http://ajax.googleapis.com/ajax/libs/jquery/1.11.2/jquery.min.js"></script>
    <script type="text/javascript">
        $(document).ready(function() {
            drawImg();
        });
        function drawImg() {
            try {
                var canvas = document.getElementById("myCanvas");
                var context = canvas.getContext("2d");
                var img = new Image();
                img.src = $('#profileImg');
                context.drawImage(img, 40, 40);
                var dataURL = canvas.toDataURL("image/jpeg");
                alert(dataURL);
            } catch (e) {
                if (e.name == "NS_ERROR_NOT_AVAILABLE") {
                    // This is a bug in Firefox. The easiest fix is to simply keep trying until the error goes away, 
                    //since no event fires at the correct time.
                    // Wait before trying again; you can change the length of this delay.
                    setTimeout(drawImg, 100);
                } else {
                    throw e;
                }
            }
        }
    </script>
</body>

也适用于 IE。希望这有帮助。

JavaScript runtime error: Unspecified error

JavaScript runtime error: Unspecified error

javascript

runtime-error