coco
54 lines
1.4 KiB
Markdown
54 lines
1.4 KiB
Markdown
<!---
|
|
This is the API of version 1.2.0
|
|
-->
|
|
# Lifecycle
|
|
|
|
|
|
Compose has some "effects"-functions that can be used in Composables to track the lifecycle of a function.
|
|
|
|
* LaunchedEffect {}
|
|
will be called the first time a compose function is applied.
|
|
|
|
* DisposableEffect { }
|
|
Has a onDispose() which will be called when the compose function isn't part of the composition anymore.
|
|
|
|
The example below has a Button that will count up everytime it gets clicked.
|
|
When the count value gets 3, the Text() function will not be added anymore.
|
|
|
|
The first time the LifecycleDemo will be executed, the SideEffect in the if-clause will be executed.
|
|
When the count value gets 3 +onDispose{} inside the if-clause will be called.
|
|
|
|
|
|
```kotlin
|
|
@Composable
|
|
fun LifecycleDemo() {
|
|
val count = remember { mutableStateOf(0) }
|
|
|
|
Column {
|
|
Button(onClick = {
|
|
count.value++
|
|
}) {
|
|
Text("Click me")
|
|
}
|
|
|
|
if (count.value < 3) {
|
|
LaunchedEffect(Unit)
|
|
Log.d("Compose", "onactive with value: " + count.value)
|
|
}
|
|
DisposableEffect(Unit) {
|
|
onDispose {
|
|
Log.d("Compose", "onDispose because value=" + count.value)
|
|
}
|
|
}
|
|
|
|
Text(text = "You have clicked the button: " + count.value.toString())
|
|
}
|
|
}
|
|
}
|
|
```
|
|
|
|
|
|
## See also:
|
|
* [Full Example Code]({{ site.samplefolder }}/general/LifecycleDemo.kt)
|
|
|