Android编程使用自定义View实现水波进度效果示例

/**
 * 水波进度效果.
 */
public class WaterWaveView extends View {
  //边框宽度
  private int STROKE_WIDTH;
  //组件的宽，高
  private int width, height;
  /**
   * 进度条最大值和当前进度值
   */
  private float max, progress;
  /**
   * 绘制波浪的画笔
   */
  private Paint progressPaint;
  //波纹振幅与半径之比。(建议设置：<0.1)
  private static final float A = 0.05f;
  //绘制文字的画笔
  private Paint textPaint;
  //绘制边框的画笔
  private Paint circlePaint;
  /**
   * 圆弧圆心位置
   */
  private int centerX, centerY;
  //内圆所在的矩形
  private RectF circleRectF;
  public WaterWaveView(Context context) {
    super(context);
    init();
  }
  public WaterWaveView(Context context, AttributeSet attrs) {
    super(context, attrs);
    init();
  }
  public WaterWaveView(Context context, AttributeSet attrs, int defStyleAttr) {
    super(context, attrs, defStyleAttr);
    init();
  }
  //初始化
  private void init() {
    progressPaint = new Paint();
    progressPaint.setColor(Color.parseColor("#77cccc88"));
    progressPaint.setAntiAlias(true);
    textPaint = new Paint();
    textPaint.setColor(Color.WHITE);
    textPaint.setAntiAlias(true);
    circlePaint = new Paint();
    circlePaint.setStyle(Paint.Style.STROKE);
    circlePaint.setAntiAlias(true);
    circlePaint.setColor(Color.parseColor("#33333333"));
    autoRefresh();
  }
  @Override
  protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
    super.onMeasure(widthMeasureSpec, heightMeasureSpec);
    if (width == 0 || height == 0) {
      width = getWidth();
      height = getHeight();
      //计算圆弧半径和圆心点
      int circleRadius = Math.min(width, height) >> 1;
      STROKE_WIDTH = circleRadius / 10;
      circlePaint.setStrokeWidth(STROKE_WIDTH);
      centerX = width / 2;
      centerY = height / 2;
      VALID_RADIUS = circleRadius - STROKE_WIDTH;
      RADIANS_PER_X = (float) (Math.PI / VALID_RADIUS);
      circleRectF = new RectF(centerX - VALID_RADIUS, centerY - VALID_RADIUS,
          centerX + VALID_RADIUS, centerY + VALID_RADIUS);
    }
  }
  private Rect textBounds = new Rect();
  //x方向偏移量
  private int xOffset;
  @Override
  protected void onDraw(Canvas canvas) {
    super.onDraw(canvas);
    //绘制圆形边框
    canvas.drawCircle(centerX, centerY, VALID_RADIUS + (STROKE_WIDTH >> 1), circlePaint);
    //绘制水波曲线
    canvas.drawPath(getWavePath(xOffset), progressPaint);
    //绘制文字
    textPaint.setTextSize(VALID_RADIUS >> 1);
    String text1 = String.valueOf(progress);
    //测量文字长度
    float w1 = textPaint.measureText(text1);
    //测量文字高度
    textPaint.getTextBounds("8", 0, 1, textBounds);
    float h2 = textBounds.height();
    float extraW = textPaint.measureText("8") / 3;
    canvas.drawText(text1, centerX - w1 / 2 - extraW, centerY + h2 / 2, textPaint);
    textPaint.setTextSize(VALID_RADIUS / 6);
    textPaint.getTextBounds("M", 0, 1, textBounds);
    float h3 = textBounds.height();
    canvas.drawText("M", centerX + w1 / 2 - extraW + 5, centerY - (h2 / 2 - h3), textPaint);
    String text3 = "共" + String.valueOf(max) + "M";
    float w3 = textPaint.measureText(text3, 0, text3.length());
    textPaint.getTextBounds("M", 0, 1, textBounds);
    float h4 = textBounds.height();
    canvas.drawText(text3, centerX - w3 / 2, centerY + (VALID_RADIUS >> 1) + h4 / 2, textPaint);
    String text4 = "流量剩余";
    float w4 = textPaint.measureText(text4, 0, text4.length());
    textPaint.getTextBounds(text4, 0, text4.length(), textBounds);
    float h5 = textBounds.height();
    canvas.drawText(text4, centerX - w4 / 2, centerY - (VALID_RADIUS >> 1) + h5 / 2, textPaint);
  }
  //绘制水波的路径
  private Path wavePath;
  //每一个像素对应的弧度数
  private float RADIANS_PER_X;
  //去除边框后的半径（即内圆半径）
  private int VALID_RADIUS;
  /**
   * 获取水波曲线（包含圆弧部分）的Path.
   *
   * @param xOffset x方向像素偏移量.
   */
  private Path getWavePath(int xOffset) {
    if (wavePath == null) {
      wavePath = new Path();
    } else {
      wavePath.reset();
    }
    float[] startPoint = new float[2]; //波浪线起点
    float[] endPoint = new float[2]; //波浪线终点
    for (int i = 0; i <= VALID_RADIUS * 2; i += 2) {
      float x = centerX - VALID_RADIUS + i;
      float y = (float) (centerY + VALID_RADIUS * (1.0f + A) * 2 * (0.5f - progress / max)
          + VALID_RADIUS * A * Math.sin((xOffset + i) * RADIANS_PER_X));
      //只计算内圆内部的点，边框上的忽略
      if (calDistance(x, y, centerX, centerY) > VALID_RADIUS) {
        if (x < centerX) {
          continue; //左边框,继续循环
        } else {
          break; //右边框,结束循环
        }
      }
      //第1个点
      if (wavePath.isEmpty()) {
        startPoint[0] = x;
        startPoint[1] = y;
        wavePath.moveTo(x, y);
      } else {
        wavePath.lineTo(x, y);
      }
      endPoint[0] = x;
      endPoint[1] = y;
    }
    if (wavePath.isEmpty()) {
      if (progress / max >= 0.5f) {
        //满格
        wavePath.moveTo(centerX, centerY - VALID_RADIUS);
        wavePath.addCircle(centerX, centerY, VALID_RADIUS, Path.Direction.CW);
      } else {
        //空格
        return wavePath;
      }
    } else {
      //添加圆弧部分
      float startDegree = calDegreeByPosition(startPoint[0], startPoint[1]); //0~180
      float endDegree = calDegreeByPosition(endPoint[0], endPoint[1]); //180~360
      wavePath.arcTo(circleRectF, endDegree - 360, startDegree - (endDegree - 360));
    }
    return wavePath;
  }
  private float calDistance(float x1, float y1, float x2, float y2) {
    return (float) Math.sqrt((x1 - x2) * (x1 - x2) + (y1 - y2) * (y1 - y2));
  }
  //根据当前位置，计算出进度条已经转过的角度。
  private float calDegreeByPosition(float currentX, float currentY) {
    float a1 = (float) (Math.atan(1.0f * (centerX - currentX) / (currentY - centerY)) / Math.PI * 180);
    if (currentY < centerY) {
      a1 += 180;
    } else if (currentY > centerY && currentX > centerX) {
      a1 += 360;
    }
    return a1 + 90;
  }
  public void setMax(int max) {
    this.max = max;
    invalidate();
  }
  //直接设置进度值（同步）
  public void setProgressSync(float progress) {
    this.progress = progress;
    invalidate();
  }
  /**
   * 自动刷新页面，创造水波效果。组件销毁后该线城将自动停止。
   */
  private void autoRefresh() {
    new Thread(new Runnable() {
      @Override
      public void run() {
        while (!detached) {
          xOffset += (VALID_RADIUS >> 4);
          SystemClock.sleep(100);
          postInvalidate();
        }
      }
    }).start();
  }
  //标记View是否已经销毁
  private boolean detached = false;
  @Override
  protected void onDetachedFromWindow() {
    super.onDetachedFromWindow();
    detached = true;
  }
}

WaterWaveView bar = (WaterWaveView) getActivity().findViewById(R.id.water_wave_view);
    bar.setMax(500);
    bar.setProgressSync(361.8f);