Flutter - stateless vs stateful

-

Hot reload: 自動更新。(儲存後自動reload)

☝stateless widgets :the state of the widget cannot change over time.  快速鍵stless 

☝stateful widgets: the state of the widget can change over time. If a widget can change—when a user interacts with it. 與使用者互動時，部件能有所變化。 反之，則使用stateless即使。

☝Row()


Comments

Post a Comment

Popular posts from this blog

Flutter - "PlatformException(no_fragment_activity, local_auth plugin requires activity to be a FragmentActivity., null)"

-
Image
package co.et.keys import androidx.annotation.NonNull ; import io.flutter.embedding.android.FlutterFragmentActivity import io.flutter.embedding.engine.FlutterEngine import io.flutter.plugins.GeneratedPluginRegistrant class MainActivity: FlutterFragmentActivity() { override fun configureFlutterEngine(@NonNull flutterEngine: FlutterEngine) { GeneratedPluginRegistrant.registerWith(flutterEngine) ; } } <uses-permission android :name ="android.permission.USE_BIOMETRIC" /> refer 1 refer2  
Read more

Dart syntax - initSate,Build,deactive, Dispose

-
 ☝ initSate(){ super.initSate   //放置一旦載入statefulwidget後就不需一直更新的物件。 } 如字面的意思in it sate. 此功能好比statefulwidget 裡面的statelesswidget。   Called only once when the widget is created，只會執行一次，不像build() 一變動就自毀後重建。 ☝Build(BuildContext context) { //放置載入後每次有任何變動就需更新的物件。 }          - Build the widget tree         -A build is triggred every time we use setState() that re-triggre build(). ☝ deactive() {super.deactive // 放置當statefulwight自毀換頁前跟著毀的物件。例如:釋放記憶空間。 } ☝Dispose()          - When the widget/state object is removed.
Read more