图片的base64没法显示啊，报错obj

直接把你的base64字符串放到浏览器能显示吗？
另外测试一下用：
data:image/png;base64,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

我上传到服务器，返回url链接可以用的。兼容问题这是。网页会显示base64，小程序是临时路径。