android-jetpack-compose

问题 The new Jetpack compose component added to Arch component is like Flutter Ui making. How does it make the Ui though? Does it use a native code engine like Skia, or it still follows the ViewGroup way like before? 回答1: Compose creates one view currently named AndroidComposeView , which inherits ViewGroup, and it draws the widget tree on its canvas. It also processes motion/keyboard events for this view. There may be more helper views added to this view due to implementation details, but

问题 I'm studiyng Kotlin and was watching the AndroidDevSummit, more specifically the presentation "Undestanding Compose" from Leland Richardson. While the presentation (at 28min26sec), he shown the following code: @Composable fun App(items: List<String>, query: String) { val results = +memo(items, query) { items.filter { it.matches(query) } } // ... } What does the "+" plus sign before the "memo" method? 回答1: + is kind of like an operator invoke for effects. The functions that return effects just

问题 I'm going through the tutorials about Jetpack which is ran in the Android Studio 4.0(Canary), please refer to the link post below. https://developer.android.com/jetpack/compose/tutorial Everything is ready except I can't find the preview window since I try to preview the "Composable" method. Can someone give me an exact hint that where the preview window is? 回答1: You have to build the project first (Build -> Make Project). I also had to restart Android Studio in order for previews to start