英文:
How can I draw a rectangle with only one rounded corner using Canvas in Jetpack Compose?
问题
我正在进行一个项目，其中我正在使用Jetpack Compose来使用Canvas绘制一些自定义形状。具体来说，我需要绘制只有一个圆角的矩形。我知道我可以使用drawRoundRect来绘制带有圆角的矩形，但似乎只允许同时设置多个角的半径。
任何帮助或指导将不胜感激！提前感谢您。
英文:
I'm currently working on a project where I'm using Jetpack Compose to draw some custom shapes with Canvas. Specifically, I need to draw rectangles with only one rounded corner. I know that I can use drawRoundRect to draw rectangles with rounded corners, but it seems like it only allows me to set the radius for multiple corners at once.
Any help or guidance would be greatly appreciated! Thank you in advance.
答案1
得分: 4
以下是翻译好的部分：
你可以使用 RoundRect 函数，其中你可以为每个角指定圆角半径。
类似这样：
Canvas(modifier = Modifier.fillMaxSize()) {
val cornerRadius = CornerRadius(25f, 25f)
val path = Path().apply {
addRoundRect(
RoundRect(
rect = Rect(
offset = Offset(0f, 0f),
size = Size(100f, 100f),
),
topLeft = cornerRadius, // 仅为示例
)
)
}
drawPath(path, color = Color.Red)
}
英文:
You can use the RoundRect function where you can specify the corner radius for each corner.
Something like:
Canvas(modifier= Modifier.fillMaxSize()){
val cornerRadius = CornerRadius(25f, 25f)
val path = Path().apply {
addRoundRect(
RoundRect(
rect = Rect(
offset = Offset(0f, 0f),
size = Size(100f, 100f),
),
topLeft = cornerRadius, //just an example
)
)
}
drawPath(path, color = Color.Red)
}
答案2
得分: 1
RoundedCornerShape函数有多个重载，接受角落参数，单位可以是dp、Float或百分比。
fun RoundedCornerShape(
topStart: Dp = 0.dp,
topEnd: Dp = 0.dp,
bottomEnd: Dp = 0.dp,
bottomStart: Dp = 0.dp
) = RoundedCornerShape(
topStart = CornerSize(topStart),
topEnd = CornerSize(topEnd),
bottomEnd = CornerSize(bottomEnd),
bottomStart = CornerSize(bottomStart)
)
/**
* 创建以像素为单位定义大小的RoundedCornerShape。
*/
fun RoundedCornerShape(
topStart: Float = 0.0f,
topEnd: Float = 0.0f,
bottomEnd: Float = 0.0f,
bottomStart: Float = 0.0f
) = RoundedCornerShape(
topStart = CornerSize(topStart),
topEnd = CornerSize(topEnd),
bottomEnd = CornerSize(bottomEnd),
bottomStart = CornerSize(bottomStart)
)
并且你可以使用以下代码从形状绘制轮廓：
val shape = RoundedCornerShape(topStart = 20.dp)
val density = LocalDensity.current
val layoutDirection = LocalLayoutDirection.current
在Canvas内部：
drawOutline(
shape.createOutline(
size = size,
density = density,
layoutDirection = layoutDirection
),
color = Color.Red
)
英文:
RoundedCornerShape function has overloads that accepts params for corners in dp, Float or percentage
fun RoundedCornerShape(
topStart: Dp = 0.dp,
topEnd: Dp = 0.dp,
bottomEnd: Dp = 0.dp,
bottomStart: Dp = 0.dp
) = RoundedCornerShape(
topStart = CornerSize(topStart),
topEnd = CornerSize(topEnd),
bottomEnd = CornerSize(bottomEnd),
bottomStart = CornerSize(bottomStart)
)
/**
* Creates [RoundedCornerShape] with sizes defined in pixels.
*/
fun RoundedCornerShape(
topStart: Float = 0.0f,
topEnd: Float = 0.0f,
bottomEnd: Float = 0.0f,
bottomStart: Float = 0.0f
) = RoundedCornerShape(
topStart = CornerSize(topStart),
topEnd = CornerSize(topEnd),
bottomEnd = CornerSize(bottomEnd),
bottomStart = CornerSize(bottomStart)
)
And you can draw outline from shape with
val shape = RoundedCornerShape(topStart = 20.dp)
val density = LocalDensity.current
val layoutDirection = LocalLayoutDirection.current
Inside Canvas
drawOutline(
shape.createOutline(
size = size,
density = density,
layoutDirection = layoutDirection
),
color = Color.Red
)
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