从OA消息中打开微应用，提示“链接不合法”

你发的json结构不正确，message_url字段应该在oa里面，请参照我们的示例
{
     "msgtype": "oa",
     "oa": {
        "message_url": "http://dingtalk.com",
        "head": {
            "bgcolor": "FFBBBBBB",
            "text": "头部标题"
        },
        "body": {
            "title": "正文标题",
            "form": [
                {
                    "key": "姓名:",
                    "value": "张三"
                },
                {
                    "key": "年龄:",
                    "value": "20"
                },
                {
                    "key": "身高:",
                    "value": "1.8米"
                },
                {
                    "key": "体重:",
                    "value": "130斤"
                },
                {
                    "key": "学历:",
                    "value": "本科"
                },
                {
                    "key": "爱好:",
                    "value": "打球、听音乐"
                }
            ],
            "rich": {
                "num": "15.6",
                "unit": "元"
            },
            "content": "大段文本大段文本大段文本大段文本大段文本大段文本大段文本大段文本大段文本大段文本大段文本大段文本",
            "image": "@lADOADmaWMzazQKA",
            "file_count": "3",
            "author": "李四 "
        }
    }
}