Android实现环形进度条的实例

public class AttendanceProgressBar extends View {
  // 画圆环底部的画笔
  private Paint mCirclePaint;
  // 画圆环的画笔
  private Paint mRingPaint;
  // 画字体的画笔
  private Paint mTextPaint;
  // 圆形颜色
  private int mCircleColor;
  // 圆环颜色
  private int mRingColor;
  // 半径
  private float mRadius;
  // 圆环半径
  private float mRingRadius;
  // 圆环宽度
  private float mStrokeWidth;
  // 圆心x坐标
  private int mXCenter;
  // 圆心y坐标
  private int mYCenter;
  // 字的长度
  private float mTxtWidth;
  // 字的高度
  private float mTxtHeight;
  // 总进度
  private int mTotalProgress = 100;
  // 当前进度
  private int mProgress = 80;
  //字体颜色
  private int mTextColor;
  // 字体大小
  private float mTextSize;
  public AttendanceProgressBar(Context context, AttributeSet attrs) {
    super(context, attrs);
    // 获取自定义的属性
    initAttrs(context, attrs);
    initVariable();
  }
  private void initAttrs(Context context, AttributeSet attrs) {
    TypedArray typeArray = context.getTheme().obtainStyledAttributes(attrs,
        R.styleable.AttendanceProgressBar, 0, 0);
    mRadius = typeArray.getDimension(R.styleable.AttendanceProgressBar_radius, 80);
    mStrokeWidth = typeArray.getDimension(R.styleable.AttendanceProgressBar_strokeWidth, 10);
    mCircleColor = typeArray.getColor(R.styleable.AttendanceProgressBar_circleColor, 0xFFFFFFFF);
    mRingColor = typeArray.getColor(R.styleable.AttendanceProgressBar_ringColor, 0xFFFFFFFF);
    mTextColor = typeArray.getColor(R.styleable.AttendanceProgressBar_textColor, 0xFF000000);
    mTextSize = typeArray.getDimension(R.styleable.AttendanceProgressBar_textSize, 80);
    mRingRadius = mRadius + mStrokeWidth / 2;
  }
  private void initVariable() {
    mCirclePaint = new Paint();
    mCirclePaint.setAntiAlias(true);
    mCirclePaint.setColor(mCircleColor);
//    mCirclePaint.setStyle(Paint.Style.FILL);
    mCirclePaint.setStyle(Paint.Style.STROKE);
    mCirclePaint.setStrokeWidth(mStrokeWidth);
    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.setColor(mTextColor);
//    mTextPaint.setARGB(255, 255, 255, 255);
//    mTextPaint.setTextSize(mRadius / 2);
    mTextPaint.setTextSize(mTextSize);
    Paint.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);
    canvas.drawCircle(mXCenter, mYCenter, mRingRadius, mCirclePaint);
    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 + "%";
    String txt = "16/18";
    mTxtWidth = mTextPaint.measureText(txt, 0, txt.length());
//      canvas.drawText(txt, mXCenter - mTxtWidth / 2, mYCenter + mTxtHeight / 4, mTextPaint);
    canvas.drawText(txt, mXCenter - mTxtWidth / 2, mYCenter + mTxtHeight / 4 - dipToPx(10), mTextPaint);
    txt = "出勤人数";
    mTxtWidth = mTextPaint.measureText(txt, 0, txt.length());
    canvas.drawText(txt, mXCenter - mTxtWidth / 2, mYCenter + mTxtHeight / 4 + dipToPx(10), mTextPaint);
  }
  public void setProgress(int progress) {
    mProgress = progress;
    postInvalidate();
  }
  private int dipToPx(int dip) {
    float scale = getContext().getResources().getDisplayMetrics().density;
    return (int) (dip * scale + 0.5f * (dip >= 0 ? 1 : -1));
  }
}

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

<com.ztd.lieyi.widget.AttendanceProgressBar
        android:layout_gravity="center"
        android:layout_width="100dp"
        android:layout_height="100dp"
        app:radius="45dp"
        app:strokeWidth="5dp"
        app:textSize="@dimen/text_16"
        app:textColor="@color/color_333333"
        app:circleColor="@color/color_d5ebfd"
        app:ringColor="@color/color_2c9df7"/>