我有一個 Firebase 實時數(shù)據(jù)庫，它讀取傳感器數(shù)據(jù)（每 0.3 秒更新一次）并將其顯示在我的網(wǎng)頁上。在做了一些研究后，我發(fā)現(xiàn)了“漂亮的印刷”。但是，這不是我所追求的格式。我現(xiàn)在的數(shù)據(jù)顯示如下：{"Moisture":619}。我正在尋找的是：水分：619。到目前為止，每次更新數(shù)據(jù)庫中的值時，此代碼也會創(chuàng)建一個新的 {"Moisture":619}。理想的情況是更新新值，使其僅在水分之后更改值，而不是再次顯示整個內(nèi)容。我的代碼：<!DOCTYPE html><html> <head> <meta charset="utf-8"> <meta http-equiv="X-UA-Compatible" content="IE=edge"> <meta name="viewport" content="width=device-width, initial-scale=1"> <link rel="stylesheet" href="/styles.css"> <script src="https://www.gstatic.com/firebasejs/4.11.0/firebase-app.js"></script> <script src="https://www.gstatic.com/firebasejs/4.11.0/firebase-auth.js"></script> <script src="https://www.gstatic.com/firebasejs/4.11.0/firebase-database.js"></script> <script src="https://www.gstatic.com/firebasejs/4.11.0/firebase-firestore.js"></script> <script src="https://www.gstatic.com/firebasejs/4.11.0/firebase-storage.js"></script> <script src="https://www.gstatic.com/firebasejs/4.11.0/firebase-messaging.js"></script> <script> // Initialize Firebase var config = { apiKey: "xx", authDomain: "xx", databaseURL: "xx", projectId: "xx", storageBucket: "xx", messagingSenderId: "xx", appId: "xx" }; firebase.initializeApp(config); </script> <script> var database = firebase.database(); var ref = firebase.database().ref("plant-patrol/Moisture"); ref.once("value") .then(function(snapshot) { var key = snapshot.key; // "plant-patrol" var childKey = snapshot.child().key; // "Moisture" }); </script><script> var ref = firebase.database().ref();ref.on("value", function(snapshot) { console.log(snapshot.val()); var snapshotJSON = JSON.stringify(snapshot.val()); var moisture = snapshotJSON; document.write(moisture);}, function (error) { console.log("Error: " + error.code);}); </script> <script src="/script.js" defer></script> </head></html>
如何在 JS 中以人類可讀格式打印 JSON 字符串
動漫人物
2022-05-26 15:29:05
