将fabricjs画布保存为电脑上的图像

Question

我想通过点击我的html页面中的按钮将Fabric画布保存为电脑上的图像（jpg或png是相同的）。我试过一个解决方案，但不起作用：

function saveF(canvF) {
var imageCanv = canvF.toDataURL('png');
var myBlob = new Blob(['imageCanv'], { type: "image/png" });
var reader = new FileReader();
reader.onload = function (event) {
    var URL = canvF.toDataURL('png');
    document.getElementById("lnkDownload").href = URL;
};

reader.readAsDataURL(myBlob);}

这是html标签：

<a class="icon fb" href="" id="lnkDownload" download="canvas.png" style="float:left; background-color:red"><i class="fa fa-save"></i></a>

我建立了其他解决方案，但他们没有工作

Answer 1

这是我的解决方案，下载blob（有点像黑客），你可以生成文本文件，或者其他什么，有点复杂。

function saveImage(e) {
    this.href = canvas.toDataURL({
        format: 'jpeg',
        quality: 0.8
    });
    this.download = 'canvas.png'
}

var canvas = new fabric.Canvas('imageCanvas', {
    backgroundColor: 'rgb(240,240,240)'
});
canvas.setWidth(300);
canvas.setHeight(300);



var imageLoader = document.getElementById('imageLoader');
imageLoader.addEventListener('change', handleImage, false);

function handleImage(e) {
    var objects = canvas.getObjects();
    for (var i in objects) {
       objects[i].remove();
    }
    var reader = new FileReader();
    reader.onload = function (event) {
        var img = new Image();
        img.onload = function () {
            var imgInstance = new fabric.Image(img, {
               selectable: 1
            })
            canvas.add(imgInstance);
            canvas.deactivateAll().renderAll();
        }
        img.src = event.target.result;
    }
    reader.readAsDataURL(e.target.files[0]);
}



var imageSaver = document.getElementById('lnkDownload');
imageSaver.addEventListener('click', saveImage, false);

function saveImage(e) {
    this.href = canvas.toDataURL({
        format: 'png',
        quality: 0.8
    });
    this.download = 'canvas.png'
}

div#container {
    padding: 30px;
    font-family: 'verdana', lucida;
}
input {
    background-color: #ccc;
    padding: 0;
    width: 300px;
    color: #777;
}
a{
    color: #777;
    display: block;
    background-color: #ccc; 
    width: 300px;
    padding: 0;
    margin-top: 2px;
    text-decoration:none;
}

<script src="https://cdnjs.cloudflare.com/ajax/libs/fabric.js/1.5.0/fabric.min.js"></script>

<div id="container">
    <input type="file" id="imageLoader" name="imageLoader" />
    <canvas id="imageCanvas" width="300" height="300"></canvas> 
    <a id="lnkDownload" href="#">Save image</a>
</div>