Android 自定義圓形圖表

<com...SignChartView
    android:id="@+id/signChart"
    android:layout_width="265dp"
    android:layout_height="265dp"
    attrview:centerTextColor="@color/colorWhite"
    attrview:centerTextSize="@dimen/font40"
    attrview:circleWidth="20dp"
    attrview:dataTextColor="@color/colorWhite"
    attrview:dataTextSize="@dimen/font14" />

package com.signin;

import android.content.Context;
import android.content.res.TypedArray;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.graphics.Rect;
import android.graphics.RectF;
import android.util.AttributeSet;
import android.view.View;



import java.util.Random;

/**
 * Created by xxxx on 2018/8/29.
 */

public class SignChartView extends View {

    /**
     * 使用wrap_content時默認的尺寸
     */
    private static final int DEFAULT_WIDTH = 220;
    private static final int DEFAULT_HEIGHT = 220;

    /**
     * 中心座標
     */
    private int centerX;
    private int centerY;

    /**
     * 半徑
     */
    private float radius;

    /**
     * 弧形外接矩形
     */
    private RectF rectF;

    /**
     * 中間文本的大小
     */
    private Rect centerTextBound = new Rect();

    /**
     * 數據文本的大小
     */
    private Rect dataTextBound = new Rect();

    /**
     * 扇形畫筆
     */
    private Paint mArcPaint;

    /**
     * 中心文本畫筆
     */
    private Paint centerTextPaint;

    /**
     * 數據畫筆
     */
    private Paint dataPaint;

    /**
     * 數據源數字數組
     */
    private int[] numbers;

    /**
     * 數據源名稱數組
     */
    private String[] names;

    /**
     * 數據源總和
     */
    private int sum;

    /**
     * 顏色數組
     */
    private int[] colors;

    private Random random = new Random();

    //自定義屬性 Start

    /**
     * 中間字體大小
     */
    private float centerTextSize = 80;

    /**
     * 數據字體大小
     */
    private float dataTextSize = 30;

    /**
     * 中間字體顏色
     */
    private int centerTextColor = Color.BLACK;

    /**
     * 數據字體顏色
     */
    private int dataTextColor = Color.BLACK;

    /**
     * 圓圈的寬度
     */
    private float circleWidth = 100;

    //自定義屬性 End

    public SignChartView(Context context) {
        super(context);
        init();
    }

    public SignChartView(Context context, AttributeSet attrs) {
        this(context, attrs, 0);
    }

    public SignChartView(Context context, AttributeSet attrs, int defStyleAttr) {
        super(context, attrs, defStyleAttr);
        TypedArray typedArray = context.obtainStyledAttributes(attrs, R.styleable.PieView);
        centerTextSize = typedArray.getDimension(R.styleable.PieView_centerTextSize, centerTextSize);
        dataTextSize = typedArray.getDimension(R.styleable.PieView_dataTextSize, dataTextSize);
        circleWidth = typedArray.getDimension(R.styleable.PieView_circleWidth, circleWidth);
        centerTextColor = typedArray.getColor(R.styleable.PieView_centerTextColor, centerTextColor);
        dataTextColor = typedArray.getColor(R.styleable.PieView_dataTextColor, dataTextColor);
        typedArray.recycle();
        init();
    }

    /**
     * 初始化
     */
    private void init() {
        mArcPaint = new Paint();
        mArcPaint.setStrokeWidth(circleWidth);
        mArcPaint.setAntiAlias(true);
        mArcPaint.setStyle(Paint.Style.STROKE);

        centerTextPaint = new Paint();
        centerTextPaint.setTextSize(centerTextSize);
        centerTextPaint.setAntiAlias(true);
        centerTextPaint.setTextAlign(Paint.Align.CENTER);
        centerTextPaint.setColor(centerTextColor);

        dataPaint = new Paint();
        dataPaint.setStrokeWidth(2);
        dataPaint.setTextSize(dataTextSize);
        dataPaint.setAntiAlias(true);
        dataPaint.setColor(dataTextColor);
    }

    @Override
    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
        super.onMeasure(widthMeasureSpec, heightMeasureSpec);
        int measureWidthSize = MeasureSpec.getSize(widthMeasureSpec);
        int measureHeightSize = MeasureSpec.getSize(heightMeasureSpec);
        int measureWidthMode = MeasureSpec.getMode(widthMeasureSpec);
        int measureHeightMode = MeasureSpec.getMode(heightMeasureSpec);
        if (measureWidthMode == MeasureSpec.AT_MOST
                && measureHeightMode == MeasureSpec.AT_MOST) {
            setMeasuredDimension(DEFAULT_WIDTH, DEFAULT_HEIGHT);
        } else if (measureWidthMode == MeasureSpec.AT_MOST) {
            setMeasuredDimension(DEFAULT_WIDTH, measureHeightSize);
        } else if (measureHeightMode == MeasureSpec.AT_MOST) {
            setMeasuredDimension(measureWidthSize, DEFAULT_HEIGHT);
        }
    }

    @Override
    protected void onSizeChanged(int w, int h, int oldw, int oldh) {
        super.onSizeChanged(w, h, oldw, oldh);
        centerX = getMeasuredWidth() / 2;
        centerY = getMeasuredHeight() / 2;
        //設置半徑爲寬高最小值的1/4
        radius = Math.min(getMeasuredWidth(), getMeasuredHeight()) / 4;
        //設置扇形外接矩形
        rectF = new RectF(centerX - radius,
                centerY - radius,
                centerX + radius,
                centerY + radius);
    }

    @Override
    protected void onDraw(Canvas canvas) {
        super.onDraw(canvas);
        calculateAndDraw(canvas);
    }

    /**
     * 計算比例而且繪製扇形和數據
     */
    private void calculateAndDraw(Canvas canvas) {
        if (numbers == null || numbers.length == 0) {
            return;
        }
        //扇形開始度數
        int startAngle = 0;
        //所佔百分比
        float percent;
        //所佔度數
        float angle;
        for (int i = 0; i < numbers.length; i++) {
            percent = numbers[i] / (float) sum;
            //獲取百分比在360中所佔度數
            if (i == numbers.length - 1) {//保證全部度數加起來等於360
                angle = 360 - startAngle;
            } else {
                angle = (float) Math.ceil(percent * 360);
            }
            //繪製第i段扇形
            drawArc(canvas, startAngle, angle, colors[i]);
            startAngle += angle;

            //繪製數據
            if (numbers[i] <= 0) {
                continue;
            }
            //當前弧線中心點相對於縱軸的夾角度數,因爲扇形的繪製是從三點鐘方向開始，因此加90
            float arcCenterDegree = 90 + startAngle - angle / 2;
            drawData(canvas, arcCenterDegree, i, percent);
        }
        //繪製中心數字總和
        canvas.drawText(sum + "", centerX, centerY + centerTextBound.height() / 2, centerTextPaint);
    }

    /**
     * 計算每段弧度的中心座標
     *
     * @param degree 當前扇形中心度數
     */
    private float[] calculatePosition(float degree) {
        //因爲Math.sin(double a)中參數a不是度數而是弧度，因此須要將度數轉化爲弧度
        //而Math.toRadians(degree)的做用就是將度數轉化爲弧度
        //sin 一二正，三四負 sin（180-a）=sin(a)
        //扇形弧線中心點距離圓心的x座標
        float x = (float) (Math.sin(Math.toRadians(degree)) * radius);
        //cos 一四正，二三負
        //扇形弧線中心點距離圓心的y座標
        float y = (float) (Math.cos(Math.toRadians(degree)) * radius);

        //每段弧度的中心座標(扇形弧線中心點相對於view的座標)
        float startX = centerX + x;
        float startY = centerY - y;

        float[] position = new float[2];
        position[0] = startX;
        position[1] = startY;
        return position;
    }

    /**
     * 繪製數據
     *
     * @param canvas  畫布
     * @param degree  第i段弧線中心點相對於縱軸的夾角度數
     * @param i       第i段弧線
     * @param percent 數據百分比
     */
    private void drawData(Canvas canvas, float degree, int i, float percent) {
        //弧度中心座標
        float startX = calculatePosition(degree)[0];
        float startY = calculatePosition(degree)[1];

        //獲取名稱文本大小
        dataPaint.getTextBounds(names[i], 0, names[i].length(), dataTextBound);
//        //繪製名稱數據，20爲縱座標偏移量
//        canvas.drawText(names[i],
//                startX - dataTextBound.width() / 2,
//                startY + dataTextBound.height() / 2 - 20,
//                dataPaint);
//
//
//        //拼接百分比並獲取文本大小
//        DecimalFormat df = new DecimalFormat("0.0");
//        String percentString = df.format(percent * 100) + "%";
//        dataPaint.getTextBounds(percentString, 0, percentString.length(), dataTextBound);
//
//        //繪製百分比數據，20爲縱座標偏移量
//        canvas.drawText(percentString,
//                startX - dataTextBound.width() / 2,
//                startY + dataTextBound.height() * 2 - 20,
//                dataPaint);
    }

    /**
     * 繪製扇形
     *
     * @param canvas     畫布
     * @param startAngle 開始度數
     * @param angle      扇形的度數
     * @param color      顏色
     */
    private void drawArc(Canvas canvas, float startAngle, float angle, int color) {
        mArcPaint.setColor(color);
        //-0.5和+0.5是爲了讓每一個扇形之間沒有間隙
        canvas.drawArc(rectF, startAngle - 0.5f, angle + 0.5f, false, mArcPaint);
    }

    /**
     * 生成隨機顏色
     */
    private int randomColor() {
        int red = random.nextInt(256);
        int green = random.nextInt(256);
        int blue = random.nextInt(256);
        return Color.rgb(red, green, blue);
    }

    /**
     * 設置數據
     *
     * @param numbers 數字數組
     * @param names   名稱數組
     */
    public void setData(int[] numbers, String[] names) {
        sum = 0;
        if (numbers == null || numbers.length == 0 || names == null || names.length == 0) {
            return;
        }
        if (numbers.length != names.length) {
            //名稱個數與數字個數不相等
            return;
        }
        this.numbers = numbers;
        this.names = names;
        colors = new int[numbers.length];
        for (int i = 0; i < this.numbers.length; i++) {
            //計算總和
            sum += numbers[i];
            //隨機顏色
            if(numbers.length == 3){
                colors[0] = Color.rgb(43,218,97);
                colors[1] = Color.rgb(43,218,204);
                colors[2] = Color.rgb(228,91,73);
            }else{
                colors[i] = randomColor();
            }

        }
        //計算總和數字的寬高
        centerTextPaint.getTextBounds(sum + "", 0, (sum + "").length(), centerTextBound);
        invalidate();
    }
}