Android编程绘图操作之弧形绘制方法示例

/**
 * 绘制弧形图案
 * @description：
 * @author ldm
 * @date 2016-4-25 下午4:37:01
 */
public class ArcsActivity extends Activity {
  @Override
  protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(new SampleView(this));
  }
  /**
   * 自定义绘制图案的View
   *
   * @description：
   * @author ldm
   * @date 2016-4-25 下午4:19:40
   */
  private static class SampleView extends View {
    // 画圆形图案的画笔数组
    private Paint[] mPaints;
    // 画矩形的画笔
    private Paint mFramePaint;
    // 是否以矩形中心画图
    private boolean[] mUseCenters;
    // 矩形框数组
    private RectF[] mOvals;
    // 上面较大的矩形框
    private RectF mBigOval;
    // 画圆弧起点
    private float mStart;
    // 画圆弧角度
    private float mSweep;
    // 画大图形对应角标index
    private int mBigIndex;
    // 角度变化增量
    private static final float ANGLE_STEP = 3;
    // 初始角度
    private static final float START_ANGLE = 15;
    public SampleView(Context context) {
      super(context);
      mPaints = new Paint[4];
      mUseCenters = new boolean[4];
      mOvals = new RectF[4];
      mPaints[0] = new Paint();
      mPaints[0].setAntiAlias(true);// 设置抗紧钜齿
      mPaints[0].setStyle(Paint.Style.FILL);// 设置画笔填充风格
      mPaints[0].setColor(0x88FF0000);// 设置颜色
      mUseCenters[0] = false;
      mPaints[1] = new Paint(mPaints[0]);
      mPaints[1].setColor(0x8800FF00);
      mUseCenters[1] = true;
      mPaints[2] = new Paint(mPaints[0]);
      mPaints[2].setStyle(Paint.Style.STROKE);// 设置画笔空心风格
      mPaints[2].setStrokeWidth(4);// 设置画笔宽度
      mPaints[2].setColor(0x880000FF);// 设置颜色
      mUseCenters[2] = false;
      mPaints[3] = new Paint(mPaints[2]);
      mPaints[3].setColor(0x88888888);
      mUseCenters[3] = true;
      mBigOval = new RectF(40, 10, 280, 250);// 初始化较大的矩形
      mOvals[0] = new RectF(10, 270, 70, 330);// 初始化4个较小矩形
      mOvals[1] = new RectF(90, 270, 150, 330);
      mOvals[2] = new RectF(170, 270, 230, 330);
      mOvals[3] = new RectF(250, 270, 310, 330);
      mFramePaint = new Paint();
      mFramePaint.setAntiAlias(true);
      mFramePaint.setStyle(Paint.Style.STROKE);
      mFramePaint.setStrokeWidth(0);
    }
    @Override
    protected void onDraw(Canvas canvas) {
      canvas.drawColor(Color.WHITE);
      // 画大矩形
      canvas.drawRect(mBigOval, mFramePaint);
      // 在大矩形分别 画4个圆弧图形
      canvas.drawArc(mBigOval, mStart, mSweep, mUseCenters[mBigIndex],
          mPaints[mBigIndex]);
      for (int i = 0; i < 4; i++) {
        canvas.drawRect(mOvals[i], mFramePaint);// 画四个小矩形
        canvas.drawArc(mOvals[i], mStart, mSweep, mUseCenters[i],// 在四个小矩形中分别画圆弧
            mPaints[i]);
      }
      mSweep += ANGLE_STEP;// 弧度改变
      if (mSweep > 360) {// 弧度控制
        mSweep -= 360;
        mStart += START_ANGLE;
        if (mStart >= 360) {
          mStart -= 360;
        }
        mBigIndex = (mBigIndex + 1) % mOvals.length;
      }
      invalidate();
    }
  }
}