先看下效果图~是不是你需要的(Y轴的文字也有，只是需求需要把它隐藏了)
Screenshot_20221227_151816.jpg
代码如下：
class CurveLineChartView(context: Context?, attrs: AttributeSet?) : View(context, attrs) {
/**
* X轴文字画笔
*/
private val mXTextPaint = TextPaint(Paint.ANTI_ALIAS_FLAG)
/**
* Y轴文字画笔
*/
private val mYTextPaint = TextPaint(Paint.ANTI_ALIAS_FLAG)
/**
* 虚线画笔
*/
private val mDottedLinePaint = Paint(Paint.ANTI_ALIAS_FLAG)
/**
* 曲线画笔
*/
private val mCurvePaint = Paint(Paint.ANTI_ALIAS_FLAG)
/**
* X轴文字
*/
private val mXText = arrayListOf("Day1", "Day2", "Day3", "Day4", "Day5", "Day6", "Day7")
/**
* X轴边距
*/
private var startX = 50f
/**
* X轴文本间隔
*/
private var mXTextInterval = 0f
/**
* Y轴文字
*/
private var mYText = arrayListOf("0", "5", "10", "15", "20", "25")
/**
* Y轴到X轴边距
*/
private var yMarginX = dp2px(6f)
/**
* X轴到Y轴边距
*/
private var xMarginY = dp2px(12f)
/**
* Y轴0点坐标
*/
private var mStartY = 0f
/**
* Y轴文本间隔
*/
private var mYTextInterval = 0f
/**
* 每个X轴中心点坐标
*/
private val mXCentre = ArrayList<Float>()
/**
* Y轴总高度
*/
private var mYHeight = 0f
/**
* 折线的弯曲率
*/
private val smoothness = 0.36f
/**
* Y轴最大值 默认取25
*/
private var maxYValue = 25
private val mData = ArrayList<Float>()
private val mData2 = ArrayList<Float>()
init {
//初始化各个画笔
mXTextPaint.color = Color.parseColor("#999999")
mXTextPaint.strokeWidth = 1f
mXTextPaint.textSize = TypedValue.applyDimension(
TypedValue.COMPLEX_UNIT_DIP,
10f,
resources.displayMetrics
)
mYTextPaint.color = Color.parseColor("#999999")
mYTextPaint.strokeWidth = 1f
mYTextPaint.textSize = TypedValue.applyDimension(
TypedValue.COMPLEX_UNIT_DIP,
12f,
resources.displayMetrics
)
mDottedLinePaint.color = Color.parseColor("#F2F2F2")
mDottedLinePaint.strokeWidth = dp2px(1f).toFloat()
mDottedLinePaint.style = Paint.Style.STROKE
//意思是所画虚线规则是先画10个长度的实线，留下5个长度的空白
//数组规则：虚、实、虚、实---先虚再实，每个数代表长度
val effects = DashPathEffect(floatArrayOf(5f, 10f), 0f)
mDottedLinePaint.pathEffect = effects
mCurvePaint.strokeWidth = dp2px(4f).toFloat()
mCurvePaint.style = Paint.Style.STROKE
mCurvePaint.strokeCap = Paint.Cap.ROUND
}
override fun onSizeChanged(w: Int, h: Int, oldw: Int, oldh: Int) {
super.onSizeChanged(w, h, oldw, oldh)
startX = getTextWidth(mYTextPaint, maxYValue.toString()) + xMarginY
//文字总宽
var mTextTotalWidth = 0f
for (i in mXText) {
mTextTotalWidth += getTextWidth(mXTextPaint, i)
}
//文本间隔
mXTextInterval = (width - startX - mTextTotalWidth) / (mXText.size - 1)
var mTextTotalHeight = 0f
for (i in mYText) {
mTextTotalHeight += getTextHeight(mYTextPaint, i)
}
mYTextInterval = (height - yMarginX - getTextHeight(
mXTextPaint,
"Day1"
) - mTextTotalHeight) / (mYText.size - 1)
}
override fun onDraw(canvas: Canvas) {
drawXText(canvas)
drawYText(canvas)
mCurvePaint.color = Color.parseColor("#688CFD")
drawCurveLine(canvas, mData)
mCurvePaint.color = Color.parseColor("#FAA264")
drawCurveLine(canvas, mData2)
}
/**
* 画曲线
*/
private fun drawCurveLine(canvas: Canvas, data: List<Float>) {
//一个数据画点
if (data.size == 1) {
canvas.drawCircle(
mXCentre[0],
mStartY - mYHeight / maxYValue * data[0],
dp2px(1f).toFloat(),
mCurvePaint
)
return
}
val path = Path()
var lX = 0f
var lY = 0f
for ((index, item) in data.withIndex()) {
if (index == 0) {
path.moveTo(mXCentre[index], mStartY - mYHeight / maxYValue * item)
} else {
//当前点坐标
val px = mXCentre[index]
val py = mStartY - mYHeight / maxYValue * item
//上个点坐标
val firstX = mXCentre[index - 1]
val firstY = mStartY - mYHeight / maxYValue * data[index - 1]
val x1: Float = firstX + lX
val y1: Float = firstY + lY
//下个点坐标
val secondX = mXCentre[if ((index + 1) < data.size) index + 1 else index]
val secondY =
mStartY - mYHeight / maxYValue * data[if ((index + 1) < data.size) index + 1 else index]
lX = (secondX - firstX) / 2 * smoothness
lY = (secondY - firstY) / 2 * smoothness
val x2: Float = px - lX
var y2: Float = py - lY
if (y1 == py) {
y2 = y1
}
//和之前Y点坐标相等直接画直线
if (firstY == py) {
path.lineTo(px, py)
} else {
path.cubicTo(x1, y1, x2, y2, px, py)
}
}
}
canvas.drawPath(path, mCurvePaint)
}
/**
* 画Y轴文字和虚线
*/
private fun drawYText(canvas: Canvas) {
//最大文字宽度
val maxTextWidth = getTextWidth(mYTextPaint, mYText[mYText.size - 1])
//开始Y轴坐标点
var starY = getTextHeight(mYTextPaint, mYText[mYText.size - 1]).toFloat()
var minHeight = 0f
//倒叙输出
for ((index, text) in mYText.reversed().withIndex()) {
//居中画出Y轴数字
var starX = 0f
val mWidthDifference = maxTextWidth - getTextWidth(mYTextPaint, text)
if (mWidthDifference > 0) {
starX = mWidthDifference / 2
}
canvas.drawText(
text,
starX,
starY,
mYTextPaint
)
//画虚线
canvas.drawLine(
startX,
starY - (getTextHeight(mYTextPaint, text) / 2),
width.toFloat(),
starY - (getTextHeight(mYTextPaint, text) / 2),
mDottedLinePaint
)
if (index == 0) {
minHeight = starY - (getTextHeight(mYTextPaint, text) / 2)
}
if (index == mYText.size - 1) {
mStartY = starY - (getTextHeight(mYTextPaint, text) / 2)
}
starY += getTextHeight(mYTextPaint, text) + mYTextInterval
}
mYHeight = mStartY - minHeight
}
/**
* 画X轴文字
*/
private fun drawXText(canvas: Canvas) {
mXCentre.clear()
var currentX = startX
for (text in mXText) {
canvas.drawText(
text,
currentX,
height - mXTextPaint.fontMetrics.descent,
mXTextPaint
)
mXCentre.add(currentX + getTextWidth(mXTextPaint, text) / 2)
currentX += getTextWidth(mXTextPaint, text) + mXTextInterval
}
}
/**
* 获取文字的宽
*/
private fun getTextWidth(paint: Paint, str: String): Float {
return paint.measureText(str)
}
/**
* 获取文字的高
*/
private fun getTextHeight(paint: Paint, str: String): Int {
val rect = Rect()
paint.getTextBounds(str, 0, str.length, rect)
return rect.height()
}
private fun dp2px(dp: Float): Int {
val scale = context.resources.displayMetrics.density
return (dp * scale + 0.5f).toInt()
}
/**
* 设置数据源
*/
fun setData(data1: List<Float>, data2: List<Float>) {
//先找出最大值
var maxValue = 0f
for (i in data1) {
if (i > maxValue) {
maxValue = i
}
}
for (i in data2) {
if (i > maxValue) {
maxValue = i
}
}
if (maxValue <= 0) {
maxYValue = 25
mYText = arrayListOf("0", "5", "10", "15", "20", "25")
} else {
//算出Y轴的最大值 使其最大值不能大于第五条虚线
while (maxValue.toInt() % 4 != 0) {
maxValue += 1
}
maxYValue = (maxValue + (maxValue.toInt() / 4)).toInt()
mYText.clear()
for (i in 0..maxYValue step (maxYValue / 5)) {
mYText.add(i.toString())
}
}
mData.clear()
mData2.clear()
mData.addAll(data1)
mData2.addAll(data2)
invalidate()
}
}
