Question

我在angular JS中有一个指令，允许将SVG导出到PNG。这在其他浏览器中工作正常，但在IE中我收到安全错误。我尝试了各种各样的东西，但它似乎并没有起作用。我在某处读到如果我对它进行base64编码，那么这样就行了，但它没有。

我在画布上绘制SVG的代码是：

// Private function for drawing our images
var drawImage = function (canvas, ctx, svgContainer) {

    // Defer our promise
    var deferred = $q.defer();

    // Remove hidden layers
    removeHidden(angular.element(clone));

    // Create our data
    var clone = angular.element(svgContainer[0].cloneNode(true)),
        child = clone.children()[0];

    // Remove hidden layers
    removeHidden(angular.element(clone));

    var s = new XMLSerializer(),
        t = s.serializeToString(child),
        base64 = 'data:image/svg+xml;base64,' + window.btoa(t);

    console.log(base64);

    var img = new Image();

    // When the image has loaded
    img.onload = function () {

        // Create our dimensions
        var viewBox = child.getAttribute('viewBox').split(' ');

        console.log(viewBox);

        var dimensions = {
            width: viewBox[2],
            height: viewBox[3]
        };

        console.log(img.width);

        // Get our location
        getNextLocation(canvas.width, canvas.height, dimensions);

        // Draw our image using the context
        ctx.drawImage(img, 0, 0, dimensions.width / 2, dimensions.height, location.x, location.y, location.width, location.height);

        // Resolve our promise
        deferred.resolve(location);
    };

    // Set the URL of the image
    img.src = base64;

    // Return our promise
    return deferred.promise;
};

在此之前我创建了一个blob，但这也导致了安全性错误。我的主要代码是这里的一点：

// Public function to generate the image
self.generateImage = function (onSuccess) {

    // Reset our location
    location = null;
    counter = 0;

    // Get our SVG
    var target = document.getElementById(self.options.targets.containerId),
        svgContainers = angular.element(target.getElementsByClassName(self.options.targets.svgContainerClassName)),
        itemCount = svgContainers.length;

    // Get our context
    var canvas = document.getElementById('canvas'),
        ctx = canvas.getContext('2d');

    // Set our canvas height and width
    setCanvasDimensions(canvas, itemCount);

    // Create our array of promises
    var promises = [];

    // Draw our header and footer
    drawHeader(canvas, ctx);

    //// For each container
    //for (var i = 0; i < itemCount; i++) {

    //    // Get our elements
    //    var svgContainer = svgContainers[i];

    //    // Draw our image and push our promise to the array
    //    promises.push(draw(canvas, ctx, svgContainer));
    //}

    promises.push(draw(canvas, ctx, svgContainers[0]));

    // Finally add our footer to our promises array
    promises.push(drawFooter(canvas, ctx));

    // When all promises have resolve
    $q.all(promises).then(function () {

        console.log('all promises completed');

        // Get our URL as a base64 string
        var dataURL = canvas.toDataURL("image/png");

        console.log('we have the image');

        // Create our model
        var model = {
            teamName: self.options.team.name,
            sport: self.options.team.sport,
            data: dataURL
        };

        // Create our preview
        self.create(model).then(function (response) {

            console.log('saved to the database');

            // Invoke our success callback
            onSuccess(response);
        });
    })
};

正如您所看到的，我遍历每个svg容器并为每个容器绘制SVG。我已经在这段代码中评论过，只是绘制了第一张图片。从未调用 canvas.toDateURL 之后的console.log指令，我收到安全错误。

SVG是内联的。从我所看到的问题可能是由于xlns声明，但删除它仍然给我的问题：

<svg version="1.1" xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink" x="0px" y="0px"
   viewBox="0 0 259.5 131" enable-background="new 0 0 259.5 131" xml:space="preserve">

有谁知道如何解决这个问题？

Answer 1

您需要设置 img.crossOrigin= 'anonymous'; 之前 img.src=...

但是，要使其正常工作，您还需要 access-control-allow-origin: * 在图片的响应标题中设置。

要尝试该解决方案，您可以使用“ http://fabricjs.com/assets/printio.png”（已设置适当的标题）

SVG删了画布IE安全错误toDataURL

1 个答案: