雷达图

学习了大神的源代码（奈何不知大神的博客地址o(╥﹏╥)o），觉得必须记录一下，方便以后再次学习。

效果如图所示：

1.自定义雷达图控件：

public class MyPolygonView extends View {    //-------------我们必须给的模拟数据-------------    //n边形    private int n = 6;    //每个角对应的文字    private String[] text = new String[]{"语文", "数学", "英语", "生物", "化学","物理"};    //区域等级，值不能超过n边形的个数（每个角对应的值到达的层数）    private int[] area = new int[]{3,3,2,2,3,2};    //-------------View相关-------------    //View自身的宽和高    private int mHeight;    private int mWidth;    //-------------画笔相关-------------    //边框的画笔    private Paint borderPaint;    //文字的画笔    private Paint textPaint;    //区域的画笔    private Paint areaPaint;    //-------------多边形相关-------------    //n边形个数    private int num = 4;    //两个多边形之间的半径    private int r = 60;    //n边形顶点坐标    private float x, y;    //n边形角度    private float angle = (float) ((2 * Math.PI) / n);    //文字与边框的边距等级，值越大边距越小（文字与边框的距离）    private int textAlign = 5;    //-------------颜色相关-------------    //边框颜色（整个n边型的区域颜色）    private int mColor = getResources().getColor(R.color.app_polygon);    //文字颜色    private int textColor = getResources().getColor(R.color.app_black);    //区域颜色(整个连线的颜色)    private int strengthColor = Color.parseColor("#f9c172");    public MyPolygonView(Context context) {        super(context);    }    public MyPolygonView(Context context, AttributeSet attrs) {        super(context, attrs);    }    public MyPolygonView(Context context, AttributeSet attrs, int defStyleAttr) {        super(context, attrs, defStyleAttr);    }    @Override    protected void onSizeChanged(int w, int h, int oldw, int oldh) {        super.onSizeChanged(w, h, oldw, oldh);        mWidth = w;        mHeight = h;    }    @Override    protected void onDraw(Canvas canvas) {        super.onDraw(canvas);        //初始化画笔        initPaint();        //画布移到中心点        canvas.translate(mWidth / 2, mHeight / 2);        //画n边形        drawPolygon(canvas);        //画n边形的中点到顶点的线        drawLine(canvas);        //画文字        drawText(canvas);        //画蓝色区域        drawArea(canvas);    }    /**     * 初始化画笔     */    private void initPaint() {        //边框画笔        borderPaint = new Paint();        borderPaint.setAntiAlias(true);        borderPaint.setStyle(Paint.Style.FILL_AND_STROKE);        borderPaint.setColor(mColor);        borderPaint.setStrokeWidth(3);        //文字画笔        textPaint = new Paint();        textPaint.setTextSize(30);        textPaint.setColor(textColor);        textPaint.setAntiAlias(true);        //区域画笔        areaPaint = new Paint();        areaPaint.setStrokeWidth(5);        areaPaint.setColor(strengthColor);        areaPaint.setAntiAlias(true);        areaPaint.setStyle(Paint.Style.STROKE);    }    /**     * 绘制多边形     *     * @param canvas     */    private void drawPolygon(Canvas canvas) {        Path path = new Path();        //n边形数目        for (int j = 1; j <= num; j++) {            float r = j * this.r;            path.reset();            //画n边形            for (int i = 1; i <= n; i++) {                x = (float) (Math.cos(i * angle) * r);                y = (float) (Math.sin(i * angle) * r);                if (i == 1) {                    path.moveTo(x, y);                } else {                    path.lineTo(x, y);                }            }            //关闭当前轮廓。如果当前点不等于第一个点的轮廓,一条线段是自动添加的            path.close();            canvas.drawPath(path, borderPaint);        }    }    /**     * 画多边形线段     *     * @param canvas     */    private void drawLine(Canvas canvas) {        Path path = new Path();        float r = num * this.r;        for (int i = 1; i <= n; i++) {            path.reset();            x = (float) (Math.cos(i * angle) * r);            y = (float) (Math.sin(i * angle) * r);            path.lineTo(x, y);            canvas.drawPath(path, borderPaint);        }    }    /**     * 画文字     *     * @param canvas     */    private void drawText(Canvas canvas) {        float r = num * this.r;        for (int i = 1; i <= n; i++) {            //测量文字的宽高            Rect rect = new Rect();            textPaint.getTextBounds(text[i - 1], 0, text[i - 1].length(), rect);            float textWidth = rect.width();            float textHeight = rect.height();            x = (float) (Math.cos(i * angle) * r);            y = (float) (Math.sin(i * angle) * r);            //位置微调            if (x < 0) {                x = x - textWidth;            }            if (y > 25) {                y = y + textHeight;            }            //调文字与边框的边距            float LastX = x + x / num / textAlign;            float LastY = y + y / num / textAlign;            canvas.drawText(text[i - 1],LastX, LastY, textPaint);        }    }    /**     * 画区域     *     * @param canvas     */    private void drawArea(Canvas canvas) {        Path path = new Path();        for (int  i= 1;  i<= n; i++) {            float r = area[i - 1] * this.r;            x = (float) (Math.cos(i * angle) * r);            y = (float) (Math.sin(i * angle) * r);            if (i == 1) {                path.moveTo(x, y);            } else {                path.lineTo(x, y);            }        }        //关闭当前轮廓。如果当前点不等于第一个点的轮廓,一条线段是自动添加的        path.close();        canvas.drawPath(path, areaPaint);    }    public void setArea (int[] area){        this.area =area;        invalidate();    }}

2.界面布局文件xml中直接使用：

  <com.lotus.chartspagedemo.MyPolygonView                android:id="@+id/polygon"                android:layout_width="match_parent"                android:layout_height="match_parent"                android:visibility="visible" />

3.界面activity中可以设置控件颜色：

polygon.setBackgroundColor(getResources().getColor(R.color.app_blue));//雷达图的背景颜色

如果不设置背景颜色，效果就是：