圖表控制元件很多，這個多少能跟圖表控制元件扯上邊吧。
廢話不多說，看圖：

上面可以看到效果，支援各種自定義，支援點選

這裡沒有用到 自定義屬性。有興趣的可以自己設定下。直接看程式碼

    public class CircleBar extends View {
    private static final String TAG = "CircleBar";

    private RectF mColorWheelRectangle = new RectF();//圓圈的矩形範圍
    private Paint mDefaultWheelPaint;////繪製底部灰色圓圈的畫筆
 

    private Paint mColorWheelPaint;//繪製藍色扇形的畫筆
    private Paint textPaint;//中間數值文字的畫筆
    private Paint textDesPaint;//描述文字的畫筆
    private float mColorWheelRadius;
    private float circleStrokeWidth;//圓圈的線條粗細
    private float pressExtraStrokeWidth;
    private int mTextColor = getResources().getColor(R.color.blue);//預設文字顏色
 

    private int mWheelColor = getResources().getColor(R.color.blue);//預設圓環顏色

    private String mText;
    private String mTextDes;//文字的描述
    private int mTextDesSize;//描述文字的大小
    private int mCount;//為了做動畫
    private float mSweepAnglePer;//扇形弧度百分比
    private float mSweepAngle;//扇形弧度
    private int mTextSize;//文字大小
 

    private int mDistance;// 上下文字的距離
    BarAnimation anim;//動畫
    private int TIME = 1000;//時間

    public CircleBar(Context context) {
        super(context);
        init(null, 0);
    }

    public CircleBar(Context context, AttributeSet attrs) {
        super(context, attrs);
        init(attrs, 0);
    }

    public CircleBar(Context context, AttributeSet attrs, int defStyle) {
        super(context, attrs, defStyle);
        init(attrs, defStyle);
    }


    private void init(AttributeSet attrs, int defStyle) {
        //初始化一些值
        circleStrokeWidth = dip2px(getContext(), 10);
        pressExtraStrokeWidth = dip2px(getContext(), 2);
        mTextSize = dip2px(getContext(), 30);
        mTextDesSize = dip2px(getContext(), 15);
        mDistance = dip2px(getContext(), 30);//文字距離
        //外圓環的畫筆
        mColorWheelPaint = new Paint(Paint.ANTI_ALIAS_FLAG);
        mColorWheelPaint.setColor(mWheelColor);
        mColorWheelPaint.setStyle(Style.STROKE);
        mColorWheelPaint.setStrokeWidth(circleStrokeWidth);//圓圈的線條粗細
        mColorWheelPaint.setStrokeCap(Paint.Cap.ROUND);//開啟顯示邊緣為圓形
        //預設圓的畫筆
        mDefaultWheelPaint = new Paint(Paint.ANTI_ALIAS_FLAG);
        mDefaultWheelPaint.setColor(getResources().getColor(R.color.gray));
        mDefaultWheelPaint.setStyle(Style.STROKE);
        mDefaultWheelPaint.setStrokeWidth(circleStrokeWidth);//圓圈的線條粗細
        mDefaultWheelPaint.setStrokeCap(Paint.Cap.ROUND);//開啟顯示邊緣為圓形
        //數值的畫筆
        textPaint = new Paint(Paint.ANTI_ALIAS_FLAG | Paint.LINEAR_TEXT_FLAG);
        textPaint.setColor(mTextColor);
        textPaint.setStyle(Style.FILL_AND_STROKE);
        textPaint.setTextAlign(Align.LEFT);
        textPaint.setTextSize(mTextSize);
        //描述文字的畫筆
        textDesPaint = new Paint(Paint.ANTI_ALIAS_FLAG | Paint.LINEAR_TEXT_FLAG);
        textDesPaint.setColor(getResources().getColor(R.color.gray));
        textDesPaint.setStyle(Style.FILL_AND_STROKE);
        textDesPaint.setTextSize(mTextDesSize);
        textDesPaint.setTextAlign(Align.LEFT);

        mText = "0";
        mTextDes = "本次考試";
        mSweepAngle = 0;
        anim = new BarAnimation();
        anim.setDuration(TIME);
    }

    @Override
    protected void onDraw(Canvas canvas) {
        canvas.drawArc(mColorWheelRectangle, -180, 180, false, mDefaultWheelPaint);//畫外接的圓環
        canvas.drawArc(mColorWheelRectangle, -180, mSweepAnglePer, false, mColorWheelPaint);//畫圓環
        Rect bounds = new Rect();
        String textstr = mCount + "";

        textPaint.getTextBounds(textstr, 0, textstr.length(), bounds);
        textDesPaint.getTextBounds(mTextDes, 0, mTextDes.length(), bounds);

        // drawText各個屬性的意思(文字,x座標,y座標,畫筆)
        canvas.drawText(
                textstr + "",
                (mColorWheelRectangle.centerX())
                        - (textPaint.measureText(textstr) / 2),
                mColorWheelRectangle.centerY() + bounds.height() / 2 - 50,
                textPaint);
        canvas.drawText(mTextDes,
                (mColorWheelRectangle.centerX())
                        - (textDesPaint.measureText(mTextDes) / 2),
                mColorWheelRectangle.centerY() + bounds.height() / 2 - 50 - mDistance
                , textDesPaint);
    }

    @Override
    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
        int height = getDefaultSize(getSuggestedMinimumHeight(),
                heightMeasureSpec);
        int width = getDefaultSize(getSuggestedMinimumWidth(), widthMeasureSpec);
        int min = Math.min(width, height);
        setMeasuredDimension(min, min);
        mColorWheelRadius = min - circleStrokeWidth - pressExtraStrokeWidth;

        mColorWheelRectangle.set(circleStrokeWidth + pressExtraStrokeWidth, circleStrokeWidth + pressExtraStrokeWidth,
                mColorWheelRadius, mColorWheelRadius);
    }


    @Override
    public void setPressed(boolean pressed) {
        Toast.makeText(getContext(), mText, Toast.LENGTH_SHORT).show();
    }

    public void startCustomAnimation() {
        this.startAnimation(anim);
    }

    public void setText(String text) {
        mText = text;
        this.startAnimation(anim);
    }

    public void setDesText(String text) {
        mTextDes = text;
        this.startAnimation(anim);
    }

    public void setTextColor(int color) {
        mTextColor = color;
        textPaint.setColor(mTextColor);
    }

    public void setSweepAngle(float sweepAngle) {
        mSweepAngle = sweepAngle;
    }

    public void setWheelColor(int color) {
        this.mColorWheelPaint.setColor(color);
    }


    public class BarAnimation extends Animation {
        /**
         * Initializes expand collapse animation, has two types, collapse (1) and expand (0).
         * 1 will collapse view and set to gone
         */
        public BarAnimation() {

        }

        //        * 動畫類利用了applyTransformation引數中的interpolatedTime引數(從0到1)的變化特點，
//                * 實現了該View的某個屬性隨時間改變而改變。原理是在每次系統呼叫animation的applyTransformation()方法時，
//                * 改變mSweepAnglePer，mCount的值，
//                * 然後呼叫postInvalidate()不停的繪製view。
        @Override
        protected void applyTransformation(float interpolatedTime, Transformation t) {
            super.applyTransformation(interpolatedTime, t);
            //mSweepAnglePer，mCount這兩個屬性只是動畫過程中要用到的臨時屬性，
            //mText和mSweepAngle才是動畫結束之後表示扇形弧度和中間數值的真實值。
            if (interpolatedTime < 1.0f) {
                mSweepAnglePer = interpolatedTime * mSweepAngle;
                mCount = (int) (interpolatedTime * Float.parseFloat(mText));
            } else {
                mSweepAnglePer = mSweepAngle;
                mCount = Integer.parseInt(mText);
            }
            postInvalidate();
        }
    }

    public static int dip2px(Context context, float dipValue) {
        final float scale = context.getResources().getDisplayMetrics().density;
        return (int) (dipValue * scale + 0.5f);
    }

}

註釋非常清楚了。就不詳細說明了。直接在在佈局中使用。因為沒有自定義屬性，大家懂的。

這裡新增點選事件，通常繼承自view都有onClick和oLongClick事件的。這裡加進去就好

    //監聽器類介面

    public static abstract interface  OnClickListener{
        public abstract void onClick(); //單擊事件處理介面
    }

    OnClickListener   listener=null;   //監聽器類物件

    //實現這個View的監聽器

    public void setOnClickListener(OnClickListener  listener){

        this.listener = listener;   //引用監聽器類物件,在這裡可以使用監聽器類的物件

    }