问如何使用Office.js在Excel Online和PowerPoint online中读/写自定义属性？

EN

function setProperties() {
console.log("Adding custom properties ...");
Word.run(function (context) {
context.document.properties.customProperties.add("TestOBID", "WTDoc:1234");
return context.sync()
.catch(function (e) {
console.log(e.message);
})
})
}

function getProperties() {
console.log("Reading custom properties ...");
Word.run(function (context) {
var customDocProps = context.document.properties.customProperties;
context.load(customDocProps);
return context.sync()
.then(function () {
console.log("No. of custom properties:: " + customDocProps.items.length);
})
})
}