Javascript 将图像blob url转换为base64
我有一个库中的代码,我想将图像部分转换为base64 但我在将blob转换为base64时一直出错 它是设备上托管的本地html文件Javascript 将图像blob url转换为base64,javascript,jquery,webview,base64,blob,Javascript,Jquery,Webview,Base64,Blob,我有一个库中的代码,我想将图像部分转换为base64 但我在将blob转换为base64时一直出错 它是设备上托管的本地html文件 <div class="widget file-picker"><input class="ignore fake-file-input" placeholder="Click here to upload file. (< 5MB)" readonly=""><button class="btn-ico
<div class="widget file-picker"><input class="ignore fake-file-input"
placeholder="Click here to upload file. (< 5MB)" readonly=""><button class="btn-icon-only btn-reset"
aria-label="reset" type="button"><i class="icon icon-refresh"> </i></button><a
class="btn-icon-only btn-download" aria-label="download"
download="image-1562651713366.jpg389038873-13_55_28.jpg"
href="blob:file:///3efb6b21-718c-48d2-8fa1-f59520228804"><i class="icon icon-download"> </i></a>
<div class="file-feedback "></div>
<div class="file-preview"><img src="blob:file:///3efb6b21-718c-48d2-8fa1-f59520228804"></div>
</div>
更新以包含来自的评论 等待图像加载并注意
someimage
是jQuery对象
var someimage = $(".file-preview").find("img");
someimg.on("load", function () {
var canvas = document.createElement("canvas");
canvas.width = someimage.width;
canvas.height = someimage.height;
canvas.getContext("2d").drawImage(someimage[0], 0, 0);
dataURI = canvas.toDataURL();
}
错误消息是一个国宝,你不能透露?
someImage
是一个jQuery对象,你不能在画布上绘制jQuery对象。请注意,jQuery对象没有onload
属性,你需要使用。on('load',fn)
。类似地,someimage
是一个jQuery对象,因此提供给drawImage()
将导致错误。您需要.drawImage(someimage[0],0,0)代码>
var someimage = $(".file-preview").find("img");
someimg.on("load", function () {
var canvas = document.createElement("canvas");
canvas.width = someimage.width;
canvas.height = someimage.height;
canvas.getContext("2d").drawImage(someimage[0], 0, 0);
dataURI = canvas.toDataURL();
}