自定义View实现Android圆形进度条

    import android.content.Context;  
    import android.content.res.TypedArray;  
    import android.graphics.Bitmap;  
    import android.graphics.Canvas;  
    import android.graphics.Paint;  
    import android.graphics.Paint.FontMetrics;  
    import android.graphics.Paint.Style;  
    import android.graphics.RectF;  
    import android.graphics.drawable.BitmapDrawable;  
    import android.graphics.drawable.Drawable;  
    import android.util.AttributeSet;  
    import android.view.View;  
    import android.widget.ImageView;  
    import android.widget.SeekBar;  
      
    public class CycleView extends View {  
      
        Paint mPaint;  
        int progress = 30;  
        int start_degree = -90;  
      
        public CycleView(Context context,AttributeSet attrs) {  
            super(context,attrs);  
            InitResources(context,attrs);  
      
        }  
      
        int background_int;  
        int progress_int;  
        float layout_width_float;  
        int textColor_int;  
        float textSize_float;  
        int max_int;  
        Drawable thumb_double;  
        int thumbSize_int;  
      
        private void InitResources(Context context,AttributeSet attrs) {  
            TypedArray mTypedArray = context.obtainStyledAttributes(attrs,R.styleable.windows);  
      
            background_int = mTypedArray.getColor(R.styleable.windows_background,0xFF87cfe8);  
            progress_int = mTypedArray.getColor(R.styleable.windows_progressDrawable,0xFFabd800);  
            layout_width_float = mTypedArray.getDimension(R.styleable.windows_layout_width,7);  
            textColor_int = mTypedArray.getColor(R.styleable.windows_textColor,0xFFada1de);  
            textSize_float = mTypedArray.getDimension(R.styleable.windows_textSize,50);  
            max_int = mTypedArray.getInt(R.styleable.windows_max,100);  
            progress = mTypedArray.getInt(R.styleable.windows_progress,20);  
            thumb_double = mTypedArray.getDrawable(R.styleable.windows_thumb);  
            thumbSize_int = mTypedArray.getInt(R.styleable.windows_thumbSize,30);  
            mTypedArray.recycle();  
      
            if (thumb_double == null) {  
                Bitmap bitmap = Bitmap.createBitmap(thumbSize_int,thumbSize_int,Bitmap.Config.ARGB_8888);  
                // 图片画片  
                Canvas cas = new Canvas(bitmap);  
                Paint paint = new Paint();  
                paint.setStyle(Style.FILL);  
                paint.setColor(0xFF68ba32);  
                int center = thumbSize_int / 2;  
                int radius = center - 4;  
                cas.drawCircle(center,center,radius,paint);  
                thumb_double = new BitmapDrawable(getResources(),bitmap);  
            }  
      
            mPaint = new Paint();  
        }  
      
        @Override  
        protected void onDraw(Canvas canvas) {  
            super.onDraw(canvas);  
            drawProgressView(canvas);  
        }  
      
        private void drawProgressView(Canvas canvas) {  
            InitOval(canvas);  
            drawBackground(canvas);  
            drawProgress(canvas);  
            drawProgressText(canvas);  
        }  
      
        RectF oval;  
      
        private void InitOval(Canvas canvas) {  
            int center = getWidth() / 2;  
            int radius = (int) (center  - thumbSize_int / 2);  
            // 画布中央减去半径就是左上角  
            int left_top = center - radius;  
            // 画布中央加上半径就是右下角  
            int right_bottom = center + radius;  
      
            if (oval == null) {  
                oval = new RectF(left_top,left_top,right_bottom,right_bottom);  
            }  
        }  
      
        /** 
         * 绘制进度文字 
         *  
         * @param canvas 
         */  
        private void drawProgressText(Canvas canvas) {  
      
            mPaint.setTextSize(textSize_float);  
            mPaint.setColor(textColor_int);  
            mPaint.setStrokeWidth(2);  
            mPaint.setStyle(Style.FILL);  
            String progresstext = progress + "%";  
            float text_left = (getWidth() - mPaint.measureText(progresstext)) / 2;  
            FontMetrics fontMetrics = mPaint.getFontMetrics();  
            // 绘制文字是底部对齐  
            float text_top = (float) ((getHeight() / 2 + Math.ceil(fontMetrics.descent - fontMetrics.ascent) / 2));  
            canvas.drawText(progresstext,text_left,text_top,mPaint);  
        }  
      
        private void drawProgress(Canvas canvas) {  
            // 设置进度  
            mPaint.setColor(progress_int);  
            mPaint.setStrokeWidth(layout_width_float);  
            float seek = 0;  
            if (max_int > 0) {  
                seek = (float) progress / max_int * 360;  
            }  
            canvas.drawArc(oval,start_degree,seek,false,mPaint);  
      
            canvas.save();  
            int center = getWidth() / 2;  
            int radius = (int) (center - thumbSize_int / 2);  
      
            double cycle_round = (seek + start_degree) * Math.PI / 180;  
            float x = (float) (Math.cos(cycle_round) * (radius) + center - thumbSize_int / 2);  
            float y = (float) (Math.sin(cycle_round) * (radius) + center - thumbSize_int / 2);  
            thumb_double.setBounds(0,thumbSize_int);  
            canvas.translate(x,y);  
            thumb_double.draw(canvas);  
            canvas.restore();  
        }  
      
        private void drawBackground(Canvas canvas) {  
      
            mPaint.setStrokeWidth(layout_width_float);  
            mPaint.setStyle(Paint.Style.STROKE);  
            mPaint.setAntiAlias(true);  
            // 设置背景  
            mPaint.setColor(background_int);  
            canvas.drawArc(oval,360,mPaint);  
      
        }  
      
        /** 
         * 查看Seekbar源码 
         *  
         * @param progress 
         */  
        public synchronized void setProgress(int progress) {  
            if (progress > max_int) {  
                progress = max_int;  
            }  
            this.progress = progress;  
            postInvalidate();  
        }  
      
        public int getProgress() {  
            return this.progress;  
        }  
      
        @Override  
        protected void onDetachedFromWindow() {  
            super.onDetachedFromWindow();  
            if (thumb_double != null) {  
                thumb_double.setCallback(null);  
                thumb_double = null;  
            }  
        }  
      
    }  

    <?xml version="1.0" encoding="utf-8"?>  
    <resources>  
      
        <!-- 参考Seekbar -->  
        <declare-styleable name="windows">  
      
            <!-- 背景颜色 -->  
            <attr name="background" format="color" />  
            <!-- 进度颜色 -->  
            <attr name="progressDrawable" format="color" />  
            <!-- 宽度 -->  
            <attr name="layout_width" format="dimension" />  
            <!-- 字体颜色 -->  
            <attr name="textColor" format="color" />  
            <!-- 字体大小 -->  
            <attr name="textSize" format="dimension" />  
            <!-- 最大进度 -->  
            <attr name="max" format="integer" />  
            <!-- 进度 -->  
            <attr name="progress" format="integer" />  
            <!-- 进度点 -->  
            <attr name="thumb" format="reference" />  
            <!-- 进度点宽高 -->  
            <attr name="thumbSize" format="integer" />  
        </declare-styleable>  
      
    </resources>  

    <RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"  
        xmlns:tools="http://schemas.android.com/tools"  
        android:layout_width="match_parent"  
        android:layout_height="match_parent"  
        tools:context=".MainActivity" >  
      
        <com.windows.canvas.CycleView  
            android:layout_centerInParent="true"  
            xmlns:windows="http://schemas.android.com/apk/res/com.finals.canvas"  
            android:layout_width="150dp"  
            android:layout_height="150dp" />  
      
    </RelativeLayout>