<?xml version="1.0" encoding="utf-8"?><resources> <declare-styleable name="MyPb">  <attr name="circle_color" format="color" />  <attr name="circle_radius" format="dimension" /><!-- 尺寸 -->  <attr name="circle_x" format="dimension" />  <attr name="circle_y" format="dimension" /> </declare-styleable></resources>

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;// 旋轉角度 public MyPb(Context context) {  super(context, null); } public MyPb(Context context, @Nullable AttributeSet attrs) {  super(context, attrs);  // 獲取自定義的屬性  TypedArray a = context.obtainStyledAttributes(attrs, R.styleable.MyPb);  // 獲取顏色  int color = a.getColor(R.styleable.MyPb_circle_color, Color.BLACK);// 獲取不到給默認值  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);// 抗鋸齒  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毫秒執行一次 } @Override protected void onDraw(Canvas canvas) {  paint.setColor(Color.BLUE);  paint.setStrokeWidth(10);  canvas.drawCircle(cx, cy, radius, paint);// 畫圓  paint.setStrokeWidth(20);// 粗細  // 畫運動的軌跡  paint.setColor(Color.RED);  // 上下左右與圓重合，左邊為圓心的橫坐標減去半徑，上邊為縱坐標減去半徑,以此類推  RectF rectF = new RectF(cx - radius, cy - radius, cx + radius, cy + radius);  // 起始角度，旋轉角度，第三個屬性為是否填充，畫筆  canvas.drawArc(rectF, -90, sweepAngle, false, paint);  // 繪制文字  int progress = (int) (sweepAngle / 360f * 100);  paint.setTextSize(50);  paint.setStrokeWidth(0);  paint.setColor(Color.BLACK);  canvas.drawText(progress + "%", cx - 20, cy, paint); }}

<?xml version="1.0" encoding="utf-8"?><LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" xmlns:app="http://schemas.android.com/apk/res-auto" xmlns:tools="http://schemas.android.com/tools" android:layout_width="match_parent" android:layout_height="match_parent" tools:context="com.bwie.zdycircle.MainActivity"> <widget.MyPb  android:layout_width="wrap_content"  android:layout_height="wrap_content"  app:circle_color="#0000ff"  app:circle_radius="70dp"  app:circle_x="200dp"  app:circle_y="200dp" /></LinearLayout>