将firebase数据检索到android(Retrieving firebase data to android)

我尝试通过从firebase检索温度和嗡嗡声数据来制作Android应用程序

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如何向textview android显示数据？以及如何显示来自firebase的最新插入数据。谢谢

UPDATE

我试试这个代码

你能给我一个例子来向android显示数据吗？谢谢你的帮助

i try to make android app by retrieve temperature and hum data from firebase

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how to show the data to textview android? and how to show the latest inserted data from firebase. thanks

UPDATE

i try this code

can you give me an example to show the data to android please? thanks for your help

最满意答案

你需要的是一个ValueEventListener。在显示TextView的片段/活动中，您可以将ValueEventListener添加到firebase引用，如下所示：

// Get reference to firebase location where the data is stored final Firebase databaseRef = new Firebase(Constants.FIREBASE_URL); databaseRef.addValueEventListener(new ValueEventListener() { @Override public void onDataChange(DataSnapshot dataSnapshot) { Log.d(LOG_TAG,"ValueEventListener:onDataChange: " + "Data has changed"); // Get data String temperatureData = (String) dataSnapshot.getValue(); // Update UI elements here... } @Override public void onCancelled(FirebaseError firebaseError) { Log.e(LOG_TAG,"ValueEventListener:onCancelled: " + firebaseError.getMessage()); } });

只要指定位置的数据发生更改，就会触发onDataChange（）回调，因此UI始终是最新的。很强大。

作为Firebase的新手，我可以推荐这个Udacity课程： https ： //www.udacity.com/course/firebase-essentials-for-android--ud009

What you need here is a ValueEventListener. In the fragment/activity that displays your TextView, you can add a ValueEventListener to a firebase reference like this:

// Get reference to firebase location where the data is stored final Firebase databaseRef = new Firebase(Constants.FIREBASE_URL); databaseRef.addValueEventListener(new ValueEventListener() { @Override public void onDataChange(DataSnapshot dataSnapshot) { Log.d(LOG_TAG,"ValueEventListener:onDataChange: " + "Data has changed"); // Get data String temperatureData = (String) dataSnapshot.getValue(); // Update UI elements here... } @Override public void onCancelled(FirebaseError firebaseError) { Log.e(LOG_TAG,"ValueEventListener:onCancelled: " + firebaseError.getMessage()); } });

Whenever the data at the specified location changes, the onDataChange() callback is triggered, so the UI is always up-to-date. Very powerful.

As someone new to Firebase myself, I can recommend this Udacity course : https://www.udacity.com/course/firebase-essentials-for-android--ud009

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