Android Jetpack Compose中数据类的更新策略
我尝试使用一个数据类中的对象,该对象将更新一个可组合文件并按如下方式声明它:Android Jetpack Compose中数据类的更新策略,android,android-jetpack,android-jetpack-compose,Android,Android Jetpack,Android Jetpack Compose,我尝试使用一个数据类中的对象,该对象将更新一个可组合文件并按如下方式声明它: data class CounterState(var counter: Int = 0) ..... val counterState: CounterState by remember { mutableStateOf(CounterState(), structuralEqualityPolicy()) } structuralEqualityPolicy()是可组合的更新策略,定义如下: 一种策略,用于将可变
data class CounterState(var counter: Int = 0)
.....
val counterState: CounterState by remember { mutableStateOf(CounterState(), structuralEqualityPolicy()) }
structuralEqualityPolicy()
是可组合的更新策略,定义如下:
一种策略,用于将可变状态的值视为等效值(如果它们是
结构上相等
如果属性计数器更改为:counterState.counter++
Composable应该更新,但这不起作用
我使用撰写版本1.0.0-alpha06
你知道如何解决这个问题吗
import androidx.compose.foundation.Text
import androidx.compose.foundation.layout.Column
import androidx.compose.material.Button
import androidx.compose.runtime.*
import androidx.ui.tooling.preview.Preview
data class CounterState(var counter: Int = 0)
@Composable
fun dataClassRemember() {
val counterState: CounterState by remember { mutableStateOf(CounterState(), structuralEqualityPolicy()) }
Column() {
Button(onClick = {
counterState.counter++
}) {
Text(text = "Increment")
}
Text(text = "Counter value is ${counterState.counter}")
}
}
@Preview("dataClassRemember")
@Composable
fun dataClassRememberPreview() {
dataClassRemember()
}
我会试试这个:
data class CounterState(var counter: Int by remember { mutableStateOf(0)})
希望它能起作用,
安娜