安卓(Android)开发之自定义饼状图

public class PieData {   private String name;  // 名字  private float value;  // 数值  private float percentage; // 百分比   private int color = 0;  // 颜色  private float angle = 0; // 角度   public PieData(@NonNull String name, @NonNull float value) {   this.name = name;   this.value = value;  } }

 public class PieView extends View {  // 颜色表  private int[] mColors = {0xFFCCFF00, 0xFF6495ED, 0xFFE32636, 0xFF800000, 0xFF808000, 0xFFFF8C69, 0xFF808080,    0xFFE6B800, 0xFF7CFC00};  // 饼状图初始绘制角度  private float mStartAngle = 0;  // 数据  private ArrayList<PieData> mData;  // 宽高  private int mWidth, mHeight;  // 画笔  private Paint mPaint = new Paint();   public PieView(Context context) {   this(context, null);  }   public PieView(Context context, AttributeSet attrs) {   super(context, attrs);   mPaint.setStyle(Paint.Style.FILL);   mPaint.setAntiAlias(true);  }   @Override  protected void onSizeChanged(int w, int h, int oldw, int oldh) {   super.onSizeChanged(w, h, oldw, oldh);   mWidth = w;   mHeight = h;  }   @Override  protected void onDraw(Canvas canvas) {   super.onDraw(canvas);   if (null == mData)    return;   float currentStartAngle = mStartAngle;     // 当前起始角度   canvas.translate(mWidth / 2, mHeight / 2);    // 将画布坐标原点移动到中心位置   float r = (float) (Math.min(mWidth, mHeight) / 2 * 0.8); // 饼状图半径   RectF rect = new RectF(-r, -r, r, r);      // 饼状图绘制区域    for (int i = 0; i < mData.size(); i++) {    PieData pie = mData.get(i);    mPaint.setColor(pie.getColor());    canvas.drawArc(rect, currentStartAngle, pie.getAngle(), true, mPaint);    currentStartAngle += pie.getAngle();   }   }   // 设置起始角度  public void setStartAngle(int mStartAngle) {   this.mStartAngle = mStartAngle;   invalidate(); // 刷新  }   // 设置数据  public void setData(ArrayList<PieData> mData) {   this.mData = mData;   initDate(mData);   invalidate(); // 刷新  }   // 初始化数据  private void initDate(ArrayList<PieData> mData) {   if (null == mData || mData.size() == 0) // 数据有问题 直接返回    return;    float sumValue = 0;   for (int i = 0; i < mData.size(); i++) {    PieData pie = mData.get(i);     sumValue += pie.getValue();  //计算数值和     int j = i % mColors.length;  //设置颜色    pie.setColor(mColors[j]);   }    float sumAngle = 0;   for (int i = 0; i < mData.size(); i++) {    PieData pie = mData.get(i);     float percentage = pie.getValue() / sumValue; // 百分比    float angle = percentage * 360;     // 对应的角度     pie.setPercentage(percentage);     // 记录百分比    pie.setAngle(angle);       // 记录角度大小    sumAngle += angle;     Log.i("angle", "" + pie.getAngle());   }  }