Android Weekly Issue #486
All About Opt-In Annotations
Kotlin中的opt-in机制.
有一些api直接使用, 会有警告, 加上这些标记表明自己是故意为之.
This can guarantee that there has been a conscious decision made about using the API on the use site.
本文示例了:
- 如何创建.
- 如何使用.
- 真实世界中的例子.
还有java, android, api verification.
Measure, measure, measure
如何测量Android的build time.
Jetpack Compose Side-Effects III— rememberUpdatedState
rememberUpdatedState保持一个更新的引用.
@Composable
fun Timer(
buttonColour: String
) {
val timerDuration = 5000L
println("Composing timer with colour : $buttonColour")
val buttonColorUpdated by rememberUpdatedState(newValue = buttonColour)
LaunchedEffect(key1 = Unit, block = {
startTimer(timerDuration) {
println("Timer ended")
println("[1] Last pressed button color is $buttonColour")
println("[2] Last pressed button color is $buttonColorUpdated")
}
})
}
如果不用这个rememberUpdatedState, composable的参数变了, 但是launchedeffect不会重新进, 永远是第一次的值.
Compose Destinations: a simpler, safer way to navigate in Jetpack Compose
一个用于Compose导航的代码生成库: compose-destinations
讨论了传参数的方式.
代码生成是KSP, 比较先进.
How to Share Composable as Bitmap
从Composable生成Bitmap.
Exception handling in Kotlin Coroutines
协程中的异常处理.
Repository Pattern with Jetpack Compose
Repository pattern和Compose一起, 做了一个搜索单词的sample.
Speed up your build: Non-transitive R files
可以使build更快, 包体积更小.