import android.content.Context; import android.content.res.TypedArray; import android.graphics.Canvas; import android.graphics.Paint; import android.graphics.RectF; import android.graphics.Paint.FontMetrics; import android.util.AttributeSet; import android.view.View;  import com.snailws.taskscompleted.R;  /** * @author naiyu(http://snailws.com) * @version 1.0 */ public class TasksCompletedView extends View {      // 畫實心圓的畫筆     private Paint mCirclePaint;     // 畫圓環的畫筆     private Paint mRingPaint;     // 畫字體的畫筆     private Paint mTextPaint;     // 圓形顏色     private int mCircleColor;     // 圓環顏色     private int mRingColor;     // 半徑     private float mRadius;     // 圓環半徑     private float mRingRadius;     // 圓環寬度     private float mStrokeWidth;     // 圓心x坐標     private int mXCenter;     // 圓心y坐標     private int mYCenter;     // 字的長度     private float mTxtWidth;     // 字的高度     private float mTxtHeight;     // 總進度     private int mTotalProgress = 100;     // 當前進度     private int mProgress;      public TasksCompletedView(Context context, AttributeSet attrs) {         super(context, attrs);         // 獲取自定義的屬性         initAttrs(context, attrs);         initVariable();     }      private void initAttrs(Context context, AttributeSet attrs) {         TypedArray typeArray = context.getTheme().obtainStyledAttributes(attrs,                 R.styleable.TasksCompletedView, 0, 0);         mRadius = typeArray.getDimension(R.styleable.TasksCompletedView_radius, 80);         mStrokeWidth = typeArray.getDimension(R.styleable.TasksCompletedView_strokeWidth, 10);         mCircleColor = typeArray.getColor(R.styleable.TasksCompletedView_circleColor, 0xFFFFFFFF);         mRingColor = typeArray.getColor(R.styleable.TasksCompletedView_ringColor, 0xFFFFFFFF);                  mRingRadius = mRadius + mStrokeWidth / 2;     }      private void initVariable() {         mCirclePaint = new Paint();         mCirclePaint.setAntiAlias(true);         mCirclePaint.setColor(mCircleColor);         mCirclePaint.setStyle(Paint.Style.FILL);                  mRingPaint = new Paint();         mRingPaint.setAntiAlias(true);         mRingPaint.setColor(mRingColor);         mRingPaint.setStyle(Paint.Style.STROKE);         mRingPaint.setStrokeWidth(mStrokeWidth);                  mTextPaint = new Paint();         mTextPaint.setAntiAlias(true);         mTextPaint.setStyle(Paint.Style.FILL);         mTextPaint.setARGB(255, 255, 255, 255);         mTextPaint.setTextSize(mRadius / 2);                  FontMetrics fm = mTextPaint.getFontMetrics();         mTxtHeight = (int) Math.ceil(fm.descent - fm.ascent);              }      @Override     protected void onDraw(Canvas canvas) {          mXCenter = getWidth() / 2;         mYCenter = getHeight() / 2;                  canvas.drawCircle(mXCenter, mYCenter, mRadius, mCirclePaint);                  if (mProgress > 0 ) {             RectF oval = new RectF();             oval.left = (mXCenter - mRingRadius);             oval.top = (mYCenter - mRingRadius);             oval.right = mRingRadius * 2 + (mXCenter - mRingRadius);             oval.bottom = mRingRadius * 2 + (mYCenter - mRingRadius);             canvas.drawArc(oval, -90, ((float)mProgress / mTotalProgress) * 360, false, mRingPaint); // //            canvas.drawCircle(mXCenter, mYCenter, mRadius + mStrokeWidth / 2, mRingPaint);             String txt = mProgress + "%";             mTxtWidth = mTextPaint.measureText(txt, 0, txt.length());             canvas.drawText(txt, mXCenter - mTxtWidth / 2, mYCenter + mTxtHeight / 4, mTextPaint);         }     }          public void setProgress(int progress) {         mProgress = progress; //        invalidate();         postInvalidate();     }  } 

<?xml version="1.0" encoding="utf-8"?> <resources>      <declare-styleable name="TasksCompletedView">     <attr name="radius" format="dimension"/>     <attr name="strokeWidth" format="dimension"/>     <attr name="circleColor" format="color"/>     <attr name="ringColor" format="color"/>   </declare-styleable>    </resources>