宁波网站建设设计/最新新闻实时新闻

我们想自定义一个属性

让他距离顶部这么长

看图一就好

图二pading（start=24.dp）只可以让Text的顶部距离顶部24 而非基准线距离顶部24

那么 如何进行操作呢

package com.anguomob.jecpack.activity.compose.layoutimport androidx.compose.foundation.background
import androidx.compose.foundation.layout.padding
import androidx.compose.material.Text
import androidx.compose.runtime.Composable
import androidx.compose.ui.Modifier
import androidx.compose.ui.graphics.Color
import androidx.compose.ui.layout.FirstBaseline
import androidx.compose.ui.layout.layout
import androidx.compose.ui.tooling.preview.Preview
import androidx.compose.ui.unit.Dp
import androidx.compose.ui.unit.dp//this.then返回的是本身
fun Modifier.firstBaseLineToTop(firstBaseLineToTop: Dp) = this.then(//修改原色测量方式和布局位置layout { measurable, constraints ->//测量元素val placeable = measurable.measure(constraints)//测量之后 获取元素的基准线val firstBaseLine = placeable[FirstBaseline]//元素新的y坐标 =新基线值-旧基线值val placeableY = firstBaseLineToTop.roundToPx() - firstBaseLineval height=placeable.height+placeableYval width=placeable.widthlayout(width, height) {placeable.placeRelative(0, placeableY)}}
)@Preview()
@Composable
fun TextWithPaddingToBaseline() {Text(text = "Hi there",Modifier.firstBaseLineToTop(124.dp).background(Color.Red))
}