学习扔物线大大的教程 http://hencoder.com/ui-1-1/ https://github.com/hencoder/PracticeDraw1

饼图的指示文字还需要重新计算一下还有防止小扇区文字可能重叠的情况

    String[] strings = {"Froyo", "GB", "ICS", "JB", "Kitkat", "L", "M"};{
//初始化画笔等
//...paintW.setColor(Color.WHITE);paintW.setStyle(Paint.Style.FILL);paintW.setTextSize(30);paintW.setTextAlign(Paint.Align.CENTER);paintG.setColor(Color.parseColor("#72B916"));
}@Overrideprotected void onDraw(Canvas canvas) {super.onDraw(canvas);//        drawGrid(canvas);Point point = new Point(150, 650);canvas.drawLine(point.x, 100, point.x, point.y, paintW);canvas.drawLine(point.x, point.y, 1050, point.y, paintW);int gapWidth = 20;int girdWidth = 80;for (int i = 0; i < 7; i++) {int gridHeight = (i + 1) * 80;int left = point.x + i * 100 + gapWidth;int top = point.y - gridHeight;int right = left + girdWidth;int bottom = point.y;canvas.drawRect(left, top, right, bottom, paintG);}for (int i = 0; i < 7; i++) {int x = point.x + gapWidth * (i + 1) + (girdWidth) * i + girdWidth / 2;int y = point.y + 30;canvas.drawText(strings[i], x, y, paintW);}}复制代码

public class Practice11PieChartView extends View {private static final String TAG = "Practice11PieChartView";Paint paintArc = new Paint();//扇形画笔Paint mPaint = new Paint();//指示线画笔Paint textPaint = new Paint();//文字画笔RectF rectF = new RectF();int textSize = 30;int height = 0;Point centerPoint = new Point();//圆心float r;//半径public Practice11PieChartView(Context context, @Nullable AttributeSet attrs) {super(context, attrs);}@Overrideprotected void onSizeChanged(int w, int h, int oldw, int oldh) {super.onSizeChanged(w, h, oldw, oldh);height = getHeight() - 300;int left = 200;int top = 50;int right = left + height;int bottom = top + height;rectF = new RectF(left, top, right, bottom);results.add(new Result(180, 120, "#F44336", "Lollipop").setNeedMove(true));results.add(new Result(300, 60, "#FFC107", "Marshmallow"));results.add(new Result(3, 7, "#9C27B0", "Gingerbread"));results.add(new Result(13, 20, "#9E9E9E", "Ice Cream Sandwich"));results.add(new Result(36, 40, "#009688", "Jelly Bean"));results.add(new Result(80, 98, "#2196F3", "KitKat"));centerPoint.x = (right - left) / 2 + left;centerPoint.y = (bottom - top) / 2 + top;r = (right - left) / 2;mPaint.setColor(Color.WHITE);mPaint.setStrokeWidth(1);mPaint.setStyle(Paint.Style.STROKE);textPaint.setColor(Color.WHITE);textPaint.setTextSize(textSize);}ArrayList<Result> results = new ArrayList<>();@Overrideprotected void onDraw(Canvas canvas) {super.onDraw(canvas);for (Result result : results) {//画扇形drawArc(canvas, result);//画指示线drawPath(canvas, result);//是否需要离开圆心一些距离drawGap(canvas, result);}}private void drawGap(Canvas canvas, Result result) {if (result.needMove) {canvas.translate(10, 20);}}private void drawPath(Canvas canvas, Result result) {int x = (int) (centerPoint.x + r * Math.cos(result.getHalfAngle() * Math.PI / 180));int y = (int) (centerPoint.y + r * Math.sin(result.getHalfAngle() * Math.PI / 180));//判断指示线方向int[] type = getDirectionArray(x, y);Path path = new Path();path.moveTo(x, y);path.rLineTo(type[2], type[3]);path.rLineTo(type[4], type[5]);switch (type[0]) {case LEFT_TOP:case LEFT_BOTTOM:textPaint.setTextAlign(Paint.Align.RIGHT);break;case RIGHT_TOP:case RIGHT_BOTTOM:textPaint.setTextAlign(Paint.Align.LEFT);break;}canvas.drawPath(path, mPaint);int textX = type[2] + type[4] + x + type[1];int textY = type[3] + type[5] + y + textSize / 3;canvas.drawText(result.name, textX, textY, textPaint);}private int[] getDirectionArray(int x, int y) {int[] arr = new int[6];if (x < centerPoint.x) {arr[1] = arr[2] = -20;arr[4] = -100;arr[5] = 0;if (y < centerPoint.y) {//左上arr[0] = LEFT_TOP;arr[3] = -20;} else {//左下arr[0] = LEFT_BOTTOM;arr[3] = 20;}} else {arr[1] = arr[2] = 20;arr[4] = 100;arr[5] = 0;if (y < centerPoint.y) {//右上arr[0] = RIGHT_TOP;arr[3] = -20;} else {//右下arr[0] = RIGHT_BOTTOM;arr[3] = 20;}}return arr;}// TODO: 2017/7/13  防止重叠final int LEFT_TOP = 0;final int LEFT_BOTTOM = 1;final int RIGHT_TOP = 2;final int RIGHT_BOTTOM = 3;private void drawArc(Canvas canvas, Result result) {paintArc.setColor(result.color);canvas.drawArc(rectF, result.startAngle, result.sweepAngle, true, paintArc);}private static class Result {int startAngle;int sweepAngle;int color;boolean needMove;String name;Result(int startAngle, int sweepAngle, String color, String name) {this.startAngle = startAngle;this.sweepAngle = sweepAngle;this.color = Color.parseColor(color);this.name = name;}float getHalfAngle() {return sweepAngle / 2 + startAngle;}Result setNeedMove(boolean needMove) {this.needMove = needMove;return this;}}
}复制代码