如何在枚举课程中使用不同种类的占位符

Question

在枚举类中，是否有可能为不同种类的占位持有人启用它吗？我想使用1个具有1个占位符的项目，然后使用另一个具有2个占位符的物品。我目前的代码似乎只允许我使用1位占位符。

strings.xml

<string name="size_placeholder">Size %1$d</string>
<string name="sizes_placeholder_and_placeholder">Sizes %1$d and %2$d</string>

mainActivity.kt

enum class Clothes(@StringRes val nameId: Int, val sizeId: Int, val onePlaceholder: Int, val twoPlaceholders: Int) {
    ItemA(R.string.item_a, R.string.size_placeholder, 8),
    ItemB(R.string.item_B, R.string.sizes_placeholder_and_placeholder, 0, 2);
}
...

LazyColumn(
    state = listState,
    modifier = Modifier.weight(1f)
        .padding(it)
) {
    items(items) {
        Column() {
            Text(text = stringResource(id = it.nameId))
            Text(text = stringResource(id = it.sizeId, it.onePlaceholder, it.twoPlaceholders))
        }
    }
}

预期结果

Answer 1

StringResource（）为占位符值vararg。因此，您使用：

stringResource(id = it.sizeId, it.onePlaceholder, it.twoPlaceholders)

例如，我使用空曲线活动模板在Android Studio Chipmunk中创建了一个废料项目。我将strings.xml设置为：

<resources>
  <string name="app_name">My Application</string>
  <string name="size_placeholder">Size %1$d</string>
  <string name="sizes_placeholder_and_placeholder">Sizes %1$d and %2$d</string>
  <string name="item_a">Item A</string>
  <string name="item_B">Item B</string>

</resources>

我设置mainActivity.kt be：

package com.commonsware.myapplication

import android.os.Bundle
import androidx.activity.ComponentActivity
import androidx.activity.compose.setContent
import androidx.annotation.StringRes
import androidx.compose.foundation.layout.Column
import androidx.compose.foundation.layout.fillMaxSize
import androidx.compose.foundation.lazy.LazyColumn
import androidx.compose.foundation.lazy.items
import androidx.compose.foundation.lazy.rememberLazyListState
import androidx.compose.material.MaterialTheme
import androidx.compose.material.Surface
import androidx.compose.material.Text
import androidx.compose.runtime.Composable
import androidx.compose.ui.Modifier
import androidx.compose.ui.res.stringResource
import androidx.compose.ui.tooling.preview.Preview
import com.commonsware.myapplication.ui.theme.MyApplicationTheme

class MainActivity : ComponentActivity() {
    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContent {
            MyApplicationTheme {
                // A surface container using the 'background' color from the theme
                Surface(modifier = Modifier.fillMaxSize(), color = MaterialTheme.colors.background) {
                    Content()
                }
            }
        }
    }
}

enum class Clothes(@StringRes val nameId: Int, val sizeId: Int, val onePlaceholder: Int, val twoPlaceholders: Int) {
    ItemA(R.string.item_a, R.string.size_placeholder, 8, 1337),
    ItemB(R.string.item_B, R.string.sizes_placeholder_and_placeholder, 0, 2);
}

@Preview
@Composable
fun Content() {
    val listState = rememberLazyListState()

    LazyColumn(
        state = listState
    ) {
        items(listOf(Clothes.ItemA, Clothes.ItemB)) {
            Column {
                Text(text = stringResource(id = it.nameId))
                Text(text = stringResource(id = it.sizeId, it.onePlaceholder, it.twoPlaceholders))
            }
        }
    }
}

结果，在缺乏所需的格式的同时，匹配所需的内容：

Answer 2

如果我理解您的问题，您想定义某种类型的特定分组，并彼此区分。

无论如何，我将使用密封类或一个具有不同参数的类的简单对象varargs占位符字符串的简单对象。

sealed class Clothes {
  data class FixedSizeClothing(val size: String, val placeholder: String): Clothes()

  data class MultiSizeClothing(val sizes: List<String>, val placeholders: 
  List<String>): Clothes()
}