android球形水波百分比控件代碼

本文主要介紹的是一個球形水波的百分比控件，市面上有各種形形色色的百分比控件，我一直覺得水波是最炫的，UI給了我這個機會，然而網上搜了一大堆，不是太復雜，代碼太多（反正我是調不出效果來），就是有瑕疵的，所以只好自己寫了，這裡開源出來，方便大家。有什麼問題或者建議大家留言指出。

先看效果，這裡動態圖不好截取，就貼張靜態的

對於水波百分比控件實現方法有如下幾種

• - 畫好水波形狀的bitmap，利用屬性動畫進行平移
• - 利用曲線精確繪制目標水波
• - 利用大范圍曲線與容器做交集
  

第一種比較煩，網上有這種思路實現的，代碼量比較龐大。bitmap移動時要注意的問題很多，一不小心就bug一堆了。第二種代碼量小，但需要幾何功底。很丟臉的說我算了好久。才算出公式（年代久遠，都忘了），不過這種方法計算量大，繪制時遍歷的點少。第三種方法，代碼量極少，計算量幾乎沒有，遍歷的點是第二種方法的兩倍以上。考慮到遍歷的消耗和計算的復雜度，選擇第三種。

這裡我們選擇正弦曲線和圓做交集。

 for (int i = left; i < length; i++) {
        int x = i;
        int y = (int) (Math.sin(Math.toRadians(x + mTranX) / 2) * mRadius / 4);
        path2.lineTo(x, mH + y);
      }

sin函數，x橫坐標，y縱坐標，mTranX每次偏移量， 波形起伏mRadius / 4，

核心代碼

利用圓的path與我們之前繪制的曲線做交集

Path pc = new Path();
      pc.addCircle(mCentrePoint.x, mCentrePoint.y, mRadius, Path.Direction.CCW);
      canvas.clipPath(pc, Region.Op.INTERSECT);
      canvas.drawPath(path2, mWavePaint);
      canvas.restore();

水位上升和水波起伏

while (isDraw) {
        if (mWaterLevel > mNowHeight) {
          mNowHeight = mNowHeight + mUpSpeed;
        }
        if (mStart) {
          if (mTranX > mRadius) {
            mTranX = 0;
          }
          mTranX = mTranX - mWaveSpeed;
        }
        drawUI();
      }

這裡由於動畫效果比較細膩，更新UI界面比較平凡，所以我們采用surfaceView來實現（用view實現發現有卡頓，影響體驗）

完整代碼

就一個waveview類直接布局中引用

注釋寫的應該算比較清楚了。有什麼疑問的可以留言

package com.aibaide.test;


import android.content.Context;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.graphics.Path;
import android.graphics.PixelFormat;
import android.graphics.Point;
import android.graphics.Region;
import android.util.AttributeSet;
import android.view.SurfaceHolder;
import android.view.SurfaceView;

/**
 * gengqiquan
 * 2016年6月2日16:16:48
 * 水波顯示百分比控件
 */
public class WaveView extends SurfaceView implements SurfaceHolder.Callback {

  Point mCentrePoint;
  int mNowHeight = 0;//當前水位
  int mRadius = 0;
  boolean mStart = false;//是否開始
  float mTextSise = 60;//文字大小
  Context mContext;
  int mTranX = 0;//水波平移量
  private Paint mCirclePaint;
  private Paint mOutCirclePaint;
  private Paint mWavePaint;
  private Paint mTextPaint;
  private SurfaceHolder holder;
  private RenderThread renderThread;
  private boolean isDraw = false;// 控制繪制的開關
  private int mCircleColor = Color.parseColor("#ff6600");//背景內圓顏色
  private int mOutCircleColor = Color.parseColor("#f5e6dc");//背景外圓顏色
  private int mWaveColor = Color.parseColor("#ff944d");//水波顏色
  private int mWaterLevel;// 水目標高度
  private int flowNum = 60;//水目標占百分比這裡是整數。
  private int mWaveSpeed = 5;//水波起伏速度
  private int mUpSpeed = 2;//水面上升速度

  /**
   * @param context
   */
  public WaveView(Context context) {
    super(context);
    // TODO Auto-generated constructor stub
    mContext = context;
    init(mContext);
  }

  /**
   * @param context
   * @param attrs
   */
  public WaveView(Context context, AttributeSet attrs) {
    super(context, attrs);
    // TODO Auto-generated constructor stub
    mContext = context;
    init(mContext);
  }

  /**
   * @param context
   * @param attrs
   * @param defStyleAttr
   */
  public WaveView(Context context, AttributeSet attrs, int defStyleAttr) {
    super(context, attrs, defStyleAttr);
    // TODO Auto-generated constructor stub
    mContext = context;
    init(mContext);
  }

  private void init(Context context) {
    mContext = context;
    setZOrderOnTop(true);
    holder = this.getHolder();
    holder.addCallback(this);
    holder.setFormat(PixelFormat.TRANSLUCENT);
    renderThread = new RenderThread();

    mCirclePaint = new Paint();
    mCirclePaint.setColor(mCircleColor);
    mCirclePaint.setStyle(Paint.Style.FILL);
    mCirclePaint.setAntiAlias(true);

    mOutCirclePaint = new Paint();
    mOutCirclePaint.setColor(mOutCircleColor);
    mOutCirclePaint.setStyle(Paint.Style.FILL);
    mOutCirclePaint.setAntiAlias(true);

    mWavePaint = new Paint();
    mWavePaint.setStrokeWidth(1.0F);
    mWavePaint.setColor(mWaveColor);
    mWavePaint.setStyle(Paint.Style.FILL);
    mWavePaint.setAntiAlias(true);

    mTextPaint = new Paint();
    mTextPaint.setStrokeWidth(1.0F);
    mTextPaint.setColor(Color.WHITE);
    mTextPaint.setTextSize(mTextSise);
    mTextPaint.setTextAlign(Paint.Align.CENTER);
    mTextPaint.setStyle(Paint.Style.FILL);
    mTextPaint.setAntiAlias(true);


  }


  @Override
  public void surfaceChanged(SurfaceHolder holder, int format, int width, int height) {
    mRadius = (int) (0.5 * width * 0.92);
    mCentrePoint = new Point(width / 2, height / 2);
    mWaterLevel = (int) (2 * mRadius * flowNum / 100f);//算出目標水位高度
  }

  @Override
  public void surfaceCreated(SurfaceHolder holder) {
    isDraw = true;
    if (renderThread != null && !renderThread.isAlive())
      renderThread.start();

  }

  @Override
  public void surfaceDestroyed(SurfaceHolder holder) {
    isDraw = false;

  }

  /**
   * 繪制界面的線程
   *
   * @author Administrator
   */
  private class RenderThread extends Thread {
    @Override
    public void run() {
      // 不停繪制界面，這裡是異步繪制，不采用外部通知開啟繪制的方式，水波根據數據更新才會開始增長
      while (isDraw) {
        if (mWaterLevel > mNowHeight) {
          mNowHeight = mNowHeight + mUpSpeed;
        }
        if (mStart) {
          if (mTranX > mRadius) {
            mTranX = 0;
          }
          mTranX = mTranX - mWaveSpeed;
        }
        drawUI();
      }
      super.run();
    }
  }

  /**
   * 界面繪制
   */
  public void drawUI() {
    Canvas canvas = holder.lockCanvas();
    try {
      drawCanvas(canvas);
    } catch (Exception e) {
      e.printStackTrace();
    } finally {
      if (canvas != null)
        holder.unlockCanvasAndPost(canvas);
    }
  }

  private void drawCanvas(Canvas canvas) {
    //畫背景圓圈
    canvas.drawCircle(mCentrePoint.x, mCentrePoint.y, mRadius / 0.92f, mOutCirclePaint);
    canvas.drawCircle(mCentrePoint.x, mCentrePoint.y, mRadius, mCirclePaint);
    if (mStart) {
      //計算正弦曲線的路徑
      int mH = mCentrePoint.y + mRadius - mNowHeight;
      int left = - mRadius / 2;
      int length = 4 * mRadius;
      Path path2 = new Path();
      path2.moveTo(left, mH);

      for (int i = left; i < length; i++) {
        int x = i;
        int y = (int) (Math.sin(Math.toRadians(x + mTranX) / 2) * mRadius / 4);
        path2.lineTo(x, mH + y);
      }
      path2.lineTo(length, mH);
      path2.lineTo(length, mCentrePoint.y + mRadius);
      path2.lineTo(0, mCentrePoint.y + mRadius);
      path2.lineTo(0, mH);

      canvas.save();
      //這裡與圓形取交集，除去正弦曲線多畫的部分
      Path pc = new Path();
      pc.addCircle(mCentrePoint.x, mCentrePoint.y, mRadius, Path.Direction.CCW);
      canvas.clipPath(pc, Region.Op.INTERSECT);
      canvas.drawPath(path2, mWavePaint);
      canvas.restore();
      //繪制文字
      canvas.drawText(flowNum + "%", mCentrePoint.x, mCentrePoint.y, mTextPaint);
    }
  }

  public void setFlowNum(int num) {
    flowNum = num;
    mStart = true;
  }

  public void setTextSise(float s) {
    mTextSise = s;
    mTextPaint.setTextSize(s);
  }

  //設置水波起伏速度
  public void setWaveSpeed(int speed) {
    mWaveSpeed = speed;
  }

  //設置水面上升速度
  public void setUpSpeed(int speed) {
    mUpSpeed = speed;
  }

  public void setColor(int waveColor, int circleColor, int outcircleColor) {
    mWaveColor = waveColor;
    mCircleColor = circleColor;
    mOutCircleColor = outcircleColor;
    mWavePaint.setColor(mWaveColor);
    mCirclePaint.setColor(mCircleColor);
    mOutCirclePaint.setColor(mOutCircleColor);
  }
//精確算法，每次正弦曲線從曲線與圓的交集處開始
//  private int getX(double h) {
//    int x = 0;
//    int R = mRadius;
//    if (h < R) {
//      double t = 2 * R * h - h * h;
//      x = (int) (R - Math.abs(Math.sqrt(t)));
//    } else {
//      double t = -2 * R * h + h * h;
//      x = (int) (R - Math.abs(Math.sqrt(t)));
//    }
//    return x;
//  }
}

最後奉上本文的源碼：源碼下載

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