但它们不一样。角笔划不同。
我用2个分开的
Path
画出顶部的形状:
第一个黄色背景:
private val paint = Paint().apply {
isAntiAlias = false // pass true does not make change
color = Color.YELLOW
style = Paint.Style.FILL_AND_STROKE // pass only FILL does not make change
}
第二个是:
private val strokePaint = Paint().apply {
isAntiAlias = false // pass true does not make change
color = Color.BLACK
strokeWidth = 2.toPx().toFloat()
style = Paint.Style.STROKE
}
在
onDraw()
函数中,我用它们绘制:
override fun onDraw(canvas: Canvas) {
drawPath()
canvas.drawPath(path, paint)
canvas.drawPath(path, strokePaint)
// at the end, draw text and default things to avoid overlapping with background
super.onDraw(canvas)
}
并使用此路径绘制:
private fun drawPath() {
path.run {
moveTo(left + radius, top)
if (_side == SIDE_TOP) {
lineTo(pointerX - pointerSize / 2, top)
lineTo(pointerX, rect.top)
lineTo(pointerX + pointerSize / 2, top)
}
lineTo(right - radius, top)
arcTo(topRightRect, 270F, 90F, false)
lineTo(right, bottom - radius)
arcTo(bottomRightRect, 0F, 90F, false)
if (_side == SIDE_BOTTOM) {
lineTo(pointerX + pointerSize / 2, bottom)
lineTo(pointerX, rect.bottom)
lineTo(pointerX - pointerSize / 2, bottom)
}
lineTo(left + radius, bottom)
arcTo(bottomLeftRect, 90F, 90F, false)
lineTo(left, top + radius)
arcTo(topLeftRect, 180F, 90F, false)
close()
}
}
Canvas
有一些预定义的方法来绘制圆形和矩形等常见形状。在您的场景中,您可以使用 drawRoundRect
需要一个 RectF
来绘制一个矩形。
举个例子:
class RoundedRect @JvmOverloads constructor(
context: Context, attrs: AttributeSet? = null, defStyleAttr: Int = 0
) : View(context, attrs, defStyleAttr) {
private val roundCorner = 32f
private val paint = Paint().apply {
color = Color.YELLOW
style = Paint.Style.FILL
isAntiAlias = true
}
private val strokePaint = Paint().apply {
color = Color.BLACK
strokeWidth = 4f
style = Paint.Style.STROKE
isAntiAlias = true
}
private var rect = RectF(0f, 0f, 0f, 0f)
override fun onSizeChanged(w: Int, h: Int, oldw: Int, oldh: Int) {
super.onSizeChanged(w, h, oldw, oldh)
rect = RectF(0f, 0f, w.toFloat(), h.toFloat())
}
override fun onDraw(canvas: Canvas) {
super.onDraw(canvas)
canvas.drawRoundRect(rect, roundCorner, roundCorner, paint)
canvas.drawRoundRect(rect, roundCorner, roundCorner, strokePaint)
}
}
顺便说一句,如果你想使用路径绘制圆角,你必须设置
pathEffect
和 CornerPathEffect
.
class RoundedRectUsingPath @JvmOverloads constructor(
context: Context, attrs: AttributeSet? = null, defStyleAttr: Int = 0
) : View(context, attrs, defStyleAttr) {
private val roundCorner = 32f
private val paint = Paint().apply {
color = Color.YELLOW
isAntiAlias = true
pathEffect = CornerPathEffect(roundCorner)
strokeCap = Paint.Cap.ROUND
}
private val strokePaint = Paint().apply {
color = Color.BLACK
strokeWidth = 4f
isAntiAlias = true
style = Paint.Style.STROKE
pathEffect = CornerPathEffect(roundCorner)
}
private var path = Path()
private val offset = 50f
override fun onSizeChanged(w: Int, h: Int, oldw: Int, oldh: Int) {
super.onSizeChanged(w, h, oldw, oldh)
path = Path().apply {
moveTo(offset, offset)
lineTo(w.toFloat() - offset, offset)
lineTo(w.toFloat() - offset, h.toFloat() - offset)
lineTo(offset, h.toFloat() - offset)
}
path.close()
}
override fun onDraw(canvas: Canvas) {
super.onDraw(canvas)
canvas.drawPath(path, paint)
canvas.drawPath(path, strokePaint)
}
}
我花了很长时间才弄清楚那里发生了什么。
请注意,我的解决方案仅绘制了一个圆角矩形,而没有使用 路径,而是
drawRoundRect
. 的预定义方法Canvas
我正在创建一个带有边框/描边的自定义进度条。我首先想到的是创建一个
Paint
实例,将绘画的样式设置为Paint.Style.STROKE
,然后画一个圆角矩形
override fun dispatchDraw(canvas: Canvas?) {
// I do the actual initialisations outside of dispatchDraw(). This is just an example.
val paint: Paint = Paint()
val strokeWidth = 4f
val cornerRadius = 10f
val strokeColor = Color.RED
val strokeRect = RectF().apply {
set(0f, 0f, width.toFloat(), height.toFloat())
}
paint.style = Paint.Style.STROKE
paint.strokeWidth = strokeWidth
paint.color = strokeColor
canvas?.drawRoundRect(strokeRect, cornerRadius, cornerRadius, paint)
}
注意:上面的代码只画了笔画,如果你想把进度也画在里面,可以新建一个rect,设置样式 油漆
。它应该非常简单 去做。Paint.Style.FILL
首先我认为角没有正确绘制,我应该增加角半径,但这不是解决方案。在做了一些研究和测试不同的实现之后,我发现这个问题与角落无关,而是与视图本身有关。我的中风刚刚被切断并且没有完全可见。
添加 insets 是解决我的问题的关键,而且非常简单。
这是修改后的代码:
override fun dispatchDraw(canvas: Canvas?) {
// I do the actual initialisations outside of dispatchDraw(). This is just an example.
val paint: Paint = Paint()
val strokeWidth = 2f
val cornerRadius = 10f
val strokeColor = Color.RED
val strokeRect = RectF().apply {
set(0f, 0f, width.toFloat(), height.toFloat())
inset(paint.strokeWidth / 2, paint.strokeWidth / 2)
}
paint.style = Paint.Style.STROKE
paint.strokeWidth = strokeWidth
paint.color = strokeColor
canvas?.drawRoundRect(strokeRect, cornerRadius, cornerRadius, paint)
}
我只添加了一条线,将 insets 设置为笔划宽度的一半,这是被切割的确切尺寸。
inset(paint.strokeWidth / 2, paint.strokeWidth / 2)
我还稍微修改了
使其看起来不错(strokeWidth
而不是2f
)。你可以 稍后更改它以符合您的设计要求。4f
在那之后,你得到了你期望的中风。
希望我的解决方案能帮助您节省时间和精力!
只是为了创建一个圆形路径,可以考虑创建一个使用,
import com.google.android.material.shape.ShapeAppearanceModel
import com.google.android.material.shape.ShapeAppearancePathProvider
fun createRoundPath(width: Int, height: Int, roundSize: Float): Path {
val roundPath = Path()
val appearanceModel = ShapeAppearanceModel().withCornerSize(roundSize)
val rect = RectF(0f, 0f, width.toFloat(), height.toFloat())
ShapeAppearancePathProvider().calculatePath(appearanceModel, 1f, rect, roundPath)
return roundPath
}
(有趣的是,我从其他地方的 OP 那里学到了这个,当时这个问题已经发布,我猜这不存在)