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
json
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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