Android自定义View实现自动转圈效果

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package widget;

import android.content.Context;
import android.content.res.TypedArray;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.graphics.RectF;
import android.support.annotation.Nullable;
import android.util.AttributeSet;
import android.view.View;

import com.bwie.zdycircle.R;

import java.util.Timer;
import java.util.TimerTask;

/**
 * Created by Administrator on 2017/12/7.
 */

public class MyPb extends View {

 private float radius, cx, cy;
 private Paint paint;
 private float sweepAngle;// 旋转角度

 public MyPb(Context context) {
  super(context, null);
 }

 public MyPb(Context context, @Nullable AttributeSet attrs) {
  super(context, attrs);
  // 获取自定义的属性
  TypedArray a = context.obtainStyledAttributes(attrs, R.styleable.MyPb);

  // 获取颜色
  int color = a.getColor(R.styleable.MyPb_circle_color, Color.BLACK);// 获取不到给默认值
  radius = a.getDimension(R.styleable.MyPb_circle_radius, 20);
  cx = a.getDimension(R.styleable.MyPb_circle_x, 100);
  cy = a.getDimension(R.styleable.MyPb_circle_y, 100);

  // 需要回收
  a.recycle();

  paint = new Paint();
  paint.setAntiAlias(true);// 抗锯齿
  paint.setColor(color);
  paint.setStyle(Paint.Style.STROKE);// 空心

  Timer timer = new Timer();
  timer.schedule(new TimerTask() {
   @Override
   public void run() {
    if (sweepAngle > 360) {
     return;
    }
    sweepAngle += 1;
    postInvalidate();
   }
  }, 1000, 20);// 每隔20毫秒执行一次

 }

 @Override
 protected void onDraw(Canvas canvas) {
  paint.setColor(Color.BLUE);
  paint.setStrokeWidth(10);
  canvas.drawCircle(cx, cy, radius, paint);// 画圆
  paint.setStrokeWidth(20);// 粗细
  // 画运动的轨迹
  paint.setColor(Color.RED);
  // 上下左右与圆重合，左边为圆心的横坐标减去半径，上边为纵坐标减去半径,以此类推
  RectF rectF = new RectF(cx - radius, cy - radius, cx + radius, cy + radius);
  // 起始角度，旋转角度，第三个属性为是否填充，画笔
  canvas.drawArc(rectF, -90, sweepAngle, false, paint);

  // 绘制文字
  int progress = (int) (sweepAngle / 360f * 100);
  paint.setTextSize(50);
  paint.setStrokeWidth(0);
  paint.setColor(Color.BLACK);
  canvas.drawText(progress + "%", cx - 20, cy, paint);
 }
}

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