我有一个正在保存到DataURL的画布,我可以右键单击它并将其作为图像保存到我的文件中,但如何在客户端或服务器端(Rails)将其转换为图像,以便将其发布到Facebook (使用考拉宝石)Invalid arguments to initialize an UploadableIO stage.toDataURL({
callback:
document.getElementById("newSignature");// save canvas image as data url (png format by default) document.getElementById("saveSignature").src = dataURL;
};context = canvas.getContext(&