android - 带有渐变背景的Jetpack Compose按钮？

Question

是否可以创建具有渐变背景的按钮？

@Composable
fun GradientButtonExample() {

    val horizontalGradientBrush = Brush.horizontalGradient(
        colors = listOf(
            Color(0xffF57F17),
            Color(0xffFFEE58),
            Color(0xffFFF9C4)
        )
    )


    val verticalGradientBrush = Brush.verticalGradient(
        colors = listOf(
            Color(0xff4E342E),
            Color(0xff8D6E63),
            Color(0xffD7CCC8)
        )
    )

    Button(onClick = {}) {
        Text(
            text = "Horizontal Gradient",
            modifier = Modifier
                .background(brush = horizontalGradientBrush)
        )
    }

    Button(onClick = {}) {
        Text(
            text = "Vertical Gradient",
            modifier = Modifier
                .background(brush = verticalGradientBrush)
        )
    }
}

将渐变添加到 Text与 background(brush)在 Button 之间留出余量和 Text .当我使用 modifier.background(brush = horizontalGradientBrush) 设置按钮背景时, Button是用原色绘制的，基本上什么都没有发生。是否可以设置 Button的背景？ ，而不是其他组件，具有渐变色？

Answer 1

撰写 1.0.0-alpha10
你可以这样做:

@Composable
fun GradientButton(
    text: String,
    gradient : Brush,
    modifier: Modifier = Modifier,
    onClick: () -> Unit = { },
) {
    Button(
        modifier = modifier,
        colors = ButtonDefaults.buttonColors(backgroundColor = Color.Transparent),
        contentPadding = PaddingValues(),
        onClick = { onClick() },
    ) {
        Box(
            modifier = Modifier
                .background(gradient)
                .then(modifier),
            contentAlignment = Alignment.Center,
        ) {
            Text(text = text)
        }
    }
}

使用示例:

@Composable
private fun Content() {

val gradient =
    Brush.horizontalGradient(listOf(Color(0xFF28D8A3), Color(0xFF00BEB2)))

    Column {
        GradientButton(
            text = "Gradient Button - Max Width",
            gradient = gradient,
            modifier = Modifier
                .fillMaxWidth()
                .padding(horizontal = 16.dp, vertical = 8.dp)
        )
        GradientButton(
            text = "Gradient Button - Wrap Width",
            gradient = gradient,
            modifier = Modifier
                .wrapContentWidth()
                .padding(horizontal = 16.dp, vertical = 8.dp)
        )
    }
}

结果样本: