我是微软Dynamics 365 & Power Platform方面的工程师罗勇，也是2015年7月到2018年6月连续三年Dynamics CRM/Business Solutions方面的微软最有价值专家(Microsoft MVP)，欢迎关注我的微信公众号 MSFTDynamics365erLuoYong ，回复404或者20200424可方便获取本文，同时可以在第一间得到我发布的最新博文信息，follow me!

Dynamics 365以前的经典风格界面不支持，现在新的Unified Interface支持，请参考官方文档：Define ribbon enable rules 的说明：Use this kind of rule to call a function in a JavaScript library that returns a Promise (Unified Interface) or boolean (Unified Interface and web client). 特别注意此功能仅仅支持Unified Interface。

Promises-based rules will only work on Unified Interface, so they cannot be used if classic Web Client is still being used.

对于性能的改进，这里有个博文 Turbocharge your model-driven apps by transitioning away from synchronous requests 进行了阐述，看来提升很大。

那我这里上个例子，假设我的自定义实体表单上有个提交按钮，这个会根据表单上new_account字段的值去查找该客户，看该客户的电话是否是123456789，若是的话就显示，否则不显示。我这里利用的代码如下：

"use strict";
var LuoYong = window.LuoYong || {};
LuoYong.OrderRibbon = LuoYong.OrderRibbon || {};
(function () {
    this.submitEnableRule = function (primaryControl) {
        var formContext = primaryControl;
        var account = formContext.getAttribute("new_account").getValue();
        if (account) {
            const req = new XMLHttpRequest();
            req.open("GET", Xrm.Utility.getGlobalContext().getClientUrl() + "/api/data/v9.1/accounts(" + account[0].id.replace('{','').replace('}','') +")?$select=telephone1");
            req.setRequestHeader("Accept", "application/json");
            req.setRequestHeader("Content-Type", "application/json; charset=utf-8");
            req.setRequestHeader("OData-MaxVersion", "4.0");
            req.setRequestHeader("OData-Version", "4.0");
            return new Promise(function (resolve, reject) {
                req.onreadystatechange = function () {
                    if (req.readyState == 4) {
                        if (req.status == 200) {
                            resolve(JSON.parse(req.responseText).telephone1 === "123456789");
                        }
                        else {
                            reject(req.responseText);
                        }
                    }
                };
                req.send();
            });
        }
        else {
            return false;
        }
    }
}).call(LuoYong.OrderRibbon);
//# sourceURL=order_ribbon.js

 

然后按钮的Enable Rule我增加一个Csutom Rule，设置参考下图。

 

 

经过验证是可行有效的。