Android 弧形进度条

android弧形进度条，有详细注释的，比较简单，感兴趣的朋友可以来看看。

package  com.demo.eric.views;

import  android.content.Context;
import  android.graphics.Canvas;
import  android.graphics.Color;
import  android.graphics.Paint;
import  android.graphics.Paint.Style;
import  android.graphics.RectF;
import  android.util.AttributeSet;
import  android.view.View;

/**
 * 弧形进度条
 *
 * @author Eric
 *
 */
public  class  ArcProgressbar  extends  View {

    public  ArcProgressbar(Context context) {
        super (context);
    }

    public  ArcProgressbar(Context context, AttributeSet attrs) {
        super (context, attrs);
    }

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

    private  void  init(Canvas canvas) {
        // 画弧形的矩阵区域。
        rectBg =  new  RectF( 15 ,  15 , diameter, diameter);

        // 计算弧形的圆心和半径。
        int  cx1 = (diameter +  15 ) /  2 ;
        int  cy1 = (diameter +  15 ) /  2 ;
        int  arcRadius = (diameter -  15 ) /  2 ;
        // ProgressBar结尾和开始画2个圆，实现ProgressBar的圆角。
        mPaintCircle =  new  Paint();
        mPaintCircle.setAntiAlias( true );
        mPaintCircle.setColor(bgColor);

        canvas.drawCircle(
                ( float ) (cx1 + arcRadius * Math.cos(startAngle *  3.14  /  180 )),
                ( float ) (cy1 + arcRadius * Math.sin(startAngle *  3.14  /  180 )),
                bgStrokeWidth /  2 , mPaintCircle); // 小圆

        canvas.drawCircle(
                ( float ) (cx1 + arcRadius
                        * Math.cos(( 180  - startAngle) *  3.14  /  180 )),
                ( float ) (cy1 + arcRadius
                        * Math.sin(( 180  - startAngle) *  3.14  /  180 )),
                bgStrokeWidth /  2 , mPaintCircle); // 小圆

        // 弧形背景。
        mPaintBg =  new  Paint();
        mPaintBg.setAntiAlias( true );
        mPaintBg.setStyle(Style.STROKE);
        mPaintBg.setStrokeWidth(bgStrokeWidth);
        mPaintBg.setColor(bgColor);
        canvas.drawArc(rectBg, startAngle, endAngle,  false , mPaintBg);

        // 弧形小背景。
        if  (showSmallBg) {
            mPaintSmallBg =  new  Paint();
            mPaintSmallBg.setAntiAlias( true );
            mPaintSmallBg.setStyle(Style.STROKE);
            mPaintSmallBg.setStrokeWidth(barStrokeWidth);
            mPaintSmallBg.setColor(smallBgColor);
            canvas.drawArc(rectBg, startAngle, endAngle,  false , mPaintSmallBg);
        }

        // 弧形ProgressBar。
        mPaintBar =  new  Paint();
        mPaintBar.setAntiAlias( true );
        mPaintBar.setStyle(Style.STROKE);
        mPaintBar.setStrokeWidth(barStrokeWidth);
        mPaintBar.setColor(barColor);
        canvas.drawArc(rectBg, startAngle, progress,  false , mPaintBar);

        // 随ProgressBar移动的圆。
        if  (showMoveCircle) {
            mPaintCircle.setColor(barColor);
            canvas.drawCircle(
                    ( float ) (cx1 + arcRadius
                            * Math.cos(angleOfMoveCircle *  3.14  /  180 )),
                    ( float ) (cy1 + arcRadius
                            * Math.sin(angleOfMoveCircle *  3.14  /  180 )),
                    bgStrokeWidth /  2 , mPaintCircle); // 小圆
        }

        invalidate();
    }

    /**
     *
     * @param progress
     */
    public  void  addProgress( int  _progress) {
        progress += _progress;
        angleOfMoveCircle += _progress;
        System.out.println(progress);
        if  (progress > endAngle) {
            progress =  0 ;
            angleOfMoveCircle = startAngle;
        }
        invalidate();
    }

    /**
     * 设置弧形背景的画笔宽度。
     */
    public  void  setBgStrokeWidth( int  bgStrokeWidth) {
        this .bgStrokeWidth = bgStrokeWidth;
    }

    /**
     * 设置弧形ProgressBar的画笔宽度。
     */
    public  void  setBarStrokeWidth( int  barStrokeWidth) {
        this .barStrokeWidth = barStrokeWidth;
    }

    /**
     * 设置弧形背景的颜色。
     */
    public  void  setBgColor( int  bgColor) {
        this .bgColor = bgColor;
    }

    /**
     * 设置弧形ProgressBar的颜色。
     */
    public  void  setBarColor( int  barColor) {
        this .barColor = barColor;
    }

    /**
     * 设置弧形小背景的颜色。
     */
    public  void  setSmallBgColor( int  smallBgColor) {
        this .smallBgColor = smallBgColor;
    }

    /**
     * 设置弧形的直径。
     */
    public  void  setDiameter( int  diameter) {
        this .diameter = diameter;
    }

    /**
     * 是否显示小背景。
     */
    public  void  setShowSmallBg( boolean  showSmallBg) {
        this .showSmallBg = showSmallBg;
    }

    /**
     * 是否显示移动的小圆。
     */
    public  void  setShowMoveCircle( boolean  showMoveCircle) {
        this .showMoveCircle = showMoveCircle;
    }

    private  int  bgStrokeWidth =  44 ;
    private  int  barStrokeWidth =  15 ;
    private  int  bgColor = Color.GRAY;
    private  int  barColor = Color.RED;
    private  int  smallBgColor = Color.WHITE;
    private  int  progress =  0 ;
    private  int  angleOfMoveCircle =  140 ; // 移动小园的起始角度。
    private  int  startAngle =  140 ;
    private  int  endAngle =  260 ;
    private  Paint mPaintBar =  null ;
    private  Paint mPaintSmallBg =  null ;
    private  Paint mPaintBg =  null ;
    private  Paint mPaintCircle =  null ;
    private  RectF rectBg =  null ;
    /**
     * 直徑。
     */
    private  int  diameter =  450 ;

    private  boolean  showSmallBg =  true ; // 是否显示小背景。
    private  boolean  showMoveCircle =  true ; // 是否显示移动的小园。

}