您好,登錄后才能下訂單哦!
這篇文章主要介紹“Android怎么自定義View實(shí)現(xiàn)漸變色折線圖”,在日常操作中,相信很多人在Android怎么自定義View實(shí)現(xiàn)漸變色折線圖問題上存在疑惑,小編查閱了各式資料,整理出簡(jiǎn)單好用的操作方法,希望對(duì)大家解答”Android怎么自定義View實(shí)現(xiàn)漸變色折線圖”的疑惑有所幫助!接下來,請(qǐng)跟著小編一起來學(xué)習(xí)吧!
通過創(chuàng)建LinearGradient來實(shí)現(xiàn)顏色漸變,并將之設(shè)置到畫筆Paint的著色器Shader,繪制想要的路徑即可實(shí)現(xiàn)該效果。
實(shí)現(xiàn)代碼如下:
class GradientLineChart : View { private var viewWidth: Int = 0 private var viewHeight: Int = 0 private var chartWidth: Int = 0 private var chartHeight: Int = 0 /** * 折線寬度 */ private var lineWidth: Float = 0f /** * 網(wǎng)格線寬度 */ private var gridLineWidth: Float = 0f /** * 網(wǎng)格線顏色 */ private var gridLineColor: Int = 0 /** * 背景顏色 */ private var backgroundColorRes: Int = 0 private var linePaint: Paint? = null private var gridLinePaint: Paint? = null private var gradientColor: IntArray? = null private val rectF = RectF() private val linePath = Path() private val lineValueList = ArrayList<LineEntity>() constructor(context: Context?) : this(context, null) constructor(context: Context?, attrs: AttributeSet?) : this(context, attrs, 0) constructor(context: Context?, attrs: AttributeSet?, defStyleAttr: Int) : super(context, attrs, defStyleAttr) { lineValueList.add(LineEntity(3f, 28f)) lineValueList.add(LineEntity(7f, 2f)) lineValueList.add(LineEntity(14f, 18f)) lineValueList.add(LineEntity(17f, 12f)) lineValueList.add(LineEntity(22f, 21f)) context?.let { gradientColor = intArrayOf( ContextCompat.getColor(it, R.color.color_FFD200), ContextCompat.getColor(it, R.color.color_FF2600), ContextCompat.getColor(it, R.color.color_49E284), ContextCompat.getColor(it, R.color.color_00A5FF) ) } initAttr(attrs, defStyleAttr) initPaint() } private fun initAttr(attrs: AttributeSet?, defStyleAttr: Int) { val typeArray = context.theme.obtainStyledAttributes(attrs, R.styleable.GradientLineChart, defStyleAttr, 0) lineWidth = typeArray.getDimension( R.styleable.GradientLineChart_tc_lineWidth, DensityUtil.dp2Px(2).toFloat() ) gridLineWidth = typeArray.getDimension( R.styleable.GradientLineChart_tc_grid_line_width, DensityUtil.dp2Px(1).toFloat() ) gridLineColor = typeArray.getColor( R.styleable.GradientLineChart_tc_grid_line_color, ContextCompat.getColor(context, R.color.color_1Affffff) ) backgroundColorRes = typeArray.getColor( R.styleable.GradientLineChart_tc_background_color, ContextCompat.getColor(context, R.color.color_23242a) ) typeArray.recycle() } private fun initPaint() { linePaint = Paint() linePaint?.isAntiAlias = true linePaint?.style = Paint.Style.STROKE linePaint?.strokeWidth = lineWidth gridLinePaint = Paint() gridLinePaint?.isAntiAlias = true gridLinePaint?.style = Paint.Style.FILL gridLinePaint?.color = gridLineColor } override fun onMeasure(widthMeasureSpec: Int, heightMeasureSpec: Int) { viewWidth = MeasureSpec.getSize(widthMeasureSpec) viewHeight = MeasureSpec.getSize(heightMeasureSpec) //MUST CALL THIS setMeasuredDimension(viewWidth, viewHeight) chartWidth = viewWidth - paddingStart - paddingEnd chartHeight = viewHeight - paddingTop - paddingBottom } override fun onDraw(canvas: Canvas?) { super.onDraw(canvas) //設(shè)置畫布背景色 canvas?.drawColor(backgroundColorRes) //繪制網(wǎng)格線 drawGradLine(canvas) //繪制折線 drawLine(canvas) } /** * 繪制網(wǎng)格線 */ private fun drawGradLine(canvas: Canvas?) { gridLinePaint?.let { val yGridValues = 7 val xGridValues = 6 //Y軸網(wǎng)格線間距 val yGridDistance = (chartHeight - yGridValues * gridLineWidth) / (yGridValues - 1) for (index in 0 until yGridValues) { val left = paddingStart.toFloat() val top = paddingTop.toFloat() + index * yGridDistance + index * gridLineWidth val right = left + chartWidth val bottom = top + gridLineWidth rectF.set(left, top, right, bottom) canvas?.drawRect(rectF, it) } //X軸網(wǎng)格線間距 val xGridDistance = (chartWidth - xGridValues * gridLineWidth) / (xGridValues - 1) for (index in 0 until xGridValues) { val left = paddingStart + xGridDistance * index + gridLineWidth * index val top = paddingTop.toFloat() val right = left + gridLineWidth val bottom = top + chartHeight rectF.set(left, top, right, bottom) canvas?.drawRect(rectF, gridLinePaint!!) } } } /** * 繪制折線 */ private fun drawLine(canvas: Canvas?) { val yGridValues = 7 val xGridValues = 6 val yGridDistance = (chartHeight - yGridValues * gridLineWidth) / (yGridValues - 1) val xGridDistance = (chartWidth - xGridValues * gridLineWidth) / (xGridValues - 1) for ((index, linePoint) in lineValueList.withIndex()) { val pointX = ((linePoint.xValue - 5 * index) / 5) * xGridDistance + (xGridDistance * index) val pointY = chartHeight - (linePoint.yValue / 30 * (yGridDistance * 6)) if (index == 0) { linePath.moveTo(pointX, pointY) } else { linePath.lineTo(pointX, pointY) } } linePaint?.shader = createLineGradient(gradientColor!!) canvas?.drawPath(linePath, linePaint!!) } private fun createLineGradient(gradientColor: IntArray): LinearGradient { return LinearGradient( 0f, 0f, 0f, viewHeight.toFloat(), gradientColor, null, Shader.TileMode.CLAMP ) } } <?xml version="1.0" encoding="utf-8"?> <resources> <declare-styleable name="GradientLineChart"> <!--線寬度--> <attr name="tc_lineWidth" format="dimension" /> <!--網(wǎng)格線寬度--> <attr name="tc_grid_line_width" format="dimension" /> <!--網(wǎng)格線顏色--> <attr name="tc_grid_line_color" format="color" /> <!--等級(jí)顏色指示器寬度--> <attr name="tc_level_indicator_width" format="dimension" /> <!--背景顏色--> <attr name="tc_background_color" format="color" /> </declare-styleable> </resources>
效果如下圖:
到此,關(guān)于“Android怎么自定義View實(shí)現(xiàn)漸變色折線圖”的學(xué)習(xí)就結(jié)束了,希望能夠解決大家的疑惑。理論與實(shí)踐的搭配能更好的幫助大家學(xué)習(xí),快去試試吧!若想繼續(xù)學(xué)習(xí)更多相關(guān)知識(shí),請(qǐng)繼續(xù)關(guān)注億速云網(wǎng)站,小編會(huì)繼續(xù)努力為大家?guī)砀鄬?shí)用的文章!
免責(zé)聲明:本站發(fā)布的內(nèi)容(圖片、視頻和文字)以原創(chuàng)、轉(zhuǎn)載和分享為主,文章觀點(diǎn)不代表本網(wǎng)站立場(chǎng),如果涉及侵權(quán)請(qǐng)聯(lián)系站長(zhǎng)郵箱:is@yisu.com進(jìn)行舉報(bào),并提供相關(guān)證據(jù),一經(jīng)查實(shí),將立刻刪除涉嫌侵權(quán)內(nèi)容。