本文实例讲述了Android开发实现绘制淘宝收益图折线效果。分享给大家供大家参考,具体如下:
实现的效果我一会贴上,我先说下原理,我们知道要实现在canvas上画线,不就是要搞一个paint嘛,然后首先肯定要设置下paint的属性,那么画文字呢,不就是Textpaint吗,对,就是这么简单,接下来怎么画,折线图主要分为X轴和y轴,x轴表示日期,y表示收益,好,说道这里,大家应该知道怎么去做了,下面直接贴代码
这个方法是,画x,y坐标系的,以及上面的日期和收益了
private void drawCoordinate(Canvas canvas) { //坐标系画笔 Paint coordinatePaint = new Paint(); coordinatePaint.setAntiAlias(true); coordinatePaint.setStrokeWidth(1); coordinatePaint.setColor(getResources().getColor(R.color.c5)); //坐标系文字画笔 TextPaint coordinateTextPaint = new TextPaint(); coordinateTextPaint.setAntiAlias(true); coordinateTextPaint.setTextSize(scaleTextSize); coordinateTextPaint.setAntiAlias(true); coordinateTextPaint.setColor(scaleTextColor); coordinateTextPaint.setTextAlign(Align.CENTER); //水平的刻度线 float verticalScaleStep = getVerticalScaleStep(); coordinateTextPaint.setTextAlign(Align.RIGHT); float textHeight = getTextHeight(coordinateTextPaint, "8"); for (int i = 0; i
但是产品有个需求啊,就是点击当前日期可以查看我的收益,并且在交汇点上展示出来
private void drawCurve(Canvas canvas) { Paint curvePaint = new Paint();//曲线画笔 curvePaint.setColor(curveColor); curvePaint.setAntiAlias(true); curvePaint.setStrokeWidth(curveStrokeWidth); float horizOntalScaleStep= getHorizontalScaleStep(); float lastXPixels = 0, newYPixels = 0; float lastYPixels = 0, newXPixels = 0; float useHeight = getHeight() - bottomPadding - topPadding; for (int i = 0; i
点击交汇点,有文字提示说明,
private void drawTipRect(Canvas canvas) { if (mTouchIndex == -1) return; LinePoint point = line.getPoint(mTouchIndex); float x = point.fLineX; float y = point.fLineY; // 描绘竖线 Paint paint = new TextPaint(); PathEffect effects = new DashPathEffect(new float[]{5, 5, 5, 5}, 1); paint.setPathEffect(effects); paint.setAntiAlias(true); paint.setStrokeWidth(verticalLineStrokeWidth); paint.setColor(verticalLineColor); canvas.drawLine(x, topPadding, x, getHeight() - bottomPadding, paint); //描绘交汇圆点 paint.setPathEffect(null); paint.setStyle(Paint.Style.FILL_AND_STROKE); paint.setColor(Color.WHITE); canvas.drawCircle(x, y, circleRadius, paint); paint.setStyle(Paint.Style.STROKE); paint.setColor(circleColor); paint.setStrokeWidth(circleStrokeWidth); canvas.drawCircle(x, y, circleRadius, paint); float midY = (topPadding + getHeight() - bottomPadding) / 2; float midX = (leftPadding + getWidth() - rightPadding) / 2; //描绘圆角矩形 TextPaint textPaint = new TextPaint(); textPaint.setTextSize(tipTextSize); textPaint.setTextAlign(Align.CENTER); textPaint.setColor(tipTextColor); textPaint.setAntiAlias(true); String label = tipPrefix + point.getY(); float textWidth = textPaint.measureText(label) + 15; float textHeight = getTextHeight(textPaint, label) + 8; float hMargin = 10;//水平间距 float vMargin = 8;//垂直间距 float w = textWidth + hMargin * 2;//宽 float h = textHeight + vMargin * 2;//高 RectF rect = new RectF(); if (x > midX) { rect.right = x - hMargin; rect.left = x - w; } else { rect.left = x + hMargin; rect.right = x + w; } if (y > midY) { rect.top = y - h; rect.bottom = y - vMargin; } else { rect.bottom = y + h; rect.top = y + vMargin; } Paint roundRectPaint = new Paint(); roundRectPaint.setColor(tipRectColor); roundRectPaint.setStyle(Paint.Style.FILL); roundRectPaint.setAntiAlias(true); canvas.drawRoundRect(rect, 3, 3, roundRectPaint); // 描绘圆角矩形中间的文字 float roundTextX = (rect.left + rect.right) / 2; float roundTextY = (rect.top + rect.bottom + getTextHeight(textPaint, label)) / 2; canvas.drawText(label, roundTextX, roundTextY, textPaint); }
好了核心的代码就这么多了,由于我们把它当做的是控件再用,那么我们在初始化的时候,肯定会引入一些自定义的样式表,
private void initViews(AttributeSet attrs, int defStyle) { TypedArray typedArray = getContext().obtainStyledAttributes(attrs, R.styleable.LineGraph, defStyle, 0); scaleTextSize = typedArray.getDimension(R.styleable.LineGraph_scale_text_size, 20); scaleTextColor = typedArray.getColor(R.styleable.LineGraph_scale_text_color, getResources().getColor(R.color.c5)); tipRectColor = typedArray.getColor(R.styleable.LineGraph_tip_rect_color, getResources().getColor(R.color.c8)); tipTextSize = typedArray.getDimension(R.styleable.LineGraph_tip_text_size, 22); tipTextColor = typedArray.getColor(R.styleable.LineGraph_tip_text_color, getResources().getColor(R.color.c12)); curveStrokeWidth = typedArray.getDimension(R.styleable.LineGraph_curve_stroke_width, 4); curveColor = typedArray.getColor(R.styleable.LineGraph_curve_color, getResources().getColor(R.color.c8)); verticalLineStrokeWidth = typedArray.getDimension(R.styleable.LineGraph_vertical_line_stroke_width, 2); verticalLineColor = typedArray.getColor(R.styleable.LineGraph_vertical_line_color, getResources().getColor(R.color.c8)); circleStrokeWidth = typedArray.getDimensionPixelSize(R.styleable.LineGraph_circle_stroke_width, 3); circleColor = typedArray.getColor(R.styleable.LineGraph_circle_color, getResources().getColor(R.color.c8)); circleRadius = typedArray.getDimensionPixelSize(R.styleable.LineGraph_circle_radius, 7); typedArray.recycle(); bottomPadding = dip2px(getContext(), 20); topPadding = dip2px(getContext(), 10); leftPadding = dip2px(getContext(), 20); rightPadding = dip2px(getContext(), 10); }
样式表文件我就不多说了,行如下面的格式,
最后贴上个效果图:
git下载地址:https://github.com/xiangzhihong/lineview
或者点击此处本站下载。
更多关于Android相关内容感兴趣的读者可查看本站专题:《Android图形与图像处理技巧总结》、《Android开发入门与进阶教程》、《Android调试技巧与常见问题解决方法汇总》、《Android基本组件用法总结》、《Android视图View技巧总结》、《Android布局layout技巧总结》及《Android控件用法总结》
希望本文所述对大家Android程序设计有所帮助。