coco
51 lines
1.8 KiB
Markdown
51 lines
1.8 KiB
Markdown
<!---
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This is the API of version 1.2.0
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-->
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# LazyColumn
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A [LazyColumn](https://developer.android.com/reference/kotlin/androidx/compose/foundation/lazy/package-summary#lazycolumn) is a vertically scrolling list that only composes and lays out the currently visible items.
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It's similar to a Recyclerview in the classic Android View system.
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<p align="left">
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<img src ="{{ site.images }}/foundation/lazycolumnitems.png" height=100 width=300 />
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</p>
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```kotlin
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@Composable
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fun LazyColumnDemo() {
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val list = listOf(
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"A", "B", "C", "D"
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) + ((0..100).map { it.toString() })
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LazyColumn(modifier = Modifier.fillMaxHeight()) {
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items(items = list, itemContent = { item ->
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Log.d("COMPOSE", "This get rendered $item")
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when (item) {
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"A" -> {
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Text(text = item, style = TextStyle(fontSize = 80.sp))
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}
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"B" -> {
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Button(onClick = {}) {
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Text(text = item, style = TextStyle(fontSize = 80.sp))
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}
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}
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"C" -> {
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//Do Nothing
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}
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"D" -> {
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Text(text = item)
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}
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else -> {
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Text(text = item, style = TextStyle(fontSize = 80.sp))
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}
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}
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})
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}
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}
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```
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## See also:
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* [Official Docs]({{ site.composedoc }}/foundation/lazy/package-summary#lazycolumn)
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* [Full Example Code]({{ site.samplefolder }}/foundation/LazyColumnDemo.kt)
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<iframe width="560" height="315" src="https://www.youtube-nocookie.com/embed/1ANt65eoNhQ" title="Lazy layouts in Compose" frameborder="0" allow="accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture" allowfullscreen></iframe>
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