渐变button的实现思路

val horizontalGradient = Brush.horizontalGradient(
            colors = listOf(MaterialTheme.colors.primary, MaterialTheme.colors.primaryVariant),
            0f,
            100f
        )
        val verticalGradient = Brush.verticalGradient(
            colors = listOf(MaterialTheme.colors.primary, MaterialTheme.colors.primaryVariant),
            startY = 0f,
            endY = 100f
        )
        Text(
            text = "Horizontal gradient",
            style = typography.body2.copy(color = Color.White),
            modifier = Modifier
                .padding(12.dp)
                .clickable(onClick = {})
                .clip(RoundedCornerShape(4.dp))
                .background(brush = horizontalGradient)
                .padding(12.dp)
        )
        Text(
            text = "Vertical gradient",
            style = typography.body1.copy(color = Color.White),
            modifier = Modifier
                .padding(12.dp)
                .clickable(onClick = {})
                .clip(RoundedCornerShape(4.dp))
                .background(brush = verticalGradient)
                .padding(12.dp)
        )