public class PercentView extends View {
 private final static String TAG = PercentView.class.getSimpleName();
 private Paint mPaint;

 public PercentView(Context context) {
 super(context);
 init();
 }

 public PercentView(Context context, AttributeSet attrs) {
 super(context, attrs);
 init();
 }

 public PercentView(Context context, AttributeSet attrs, int defStyleAttr) {
 super(context, attrs, defStyleAttr);
 init();
 }

 private void init(){
 mPaint = new Paint();
 mPaint.setAntiAlias(true);
 }
 @Override
 protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
 super.onMeasure(widthMeasureSpec, heightMeasureSpec);
 int widthMode = MeasureSpec.getMode(widthMeasureSpec);
 int widthSize = MeasureSpec.getSize(widthMeasureSpec);
 int heightMode = MeasureSpec.getMode(heightMeasureSpec);
 int heightSize = MeasureSpec.getSize(heightMeasureSpec);
 Log.e(TAG, "onMeasure--widthMode-->" + widthMode);
 switch (widthMode) {
 case MeasureSpec.EXACTLY:

 break;
 case MeasureSpec.AT_MOST:

 break;
 case MeasureSpec.UNSPECIFIED:

 break;
 }
 Log.e(TAG, "onMeasure--widthSize-->" + widthSize);
 Log.e(TAG, "onMeasure--heightMode-->" + heightMode);
 Log.e(TAG, "onMeasure--heightSize-->" + heightSize);
 }

 @Override
 protected void onLayout(boolean changed, int left, int top, int right, int bottom) {
 super.onLayout(changed, left, top, right, bottom);
 Log.e(TAG, "onLayout");
 }

 @Override
 protected void onDraw(Canvas canvas) {
 super.onDraw(canvas);
 mPaint.setColor(Color.GRAY);
 // FILL填充, STROKE描边,FILL_AND_STROKE填充和描边
 mPaint.setStyle(Paint.Style.FILL_AND_STROKE);
 int with = getWidth();
 int height = getHeight();
 Log.e(TAG, "onDraw---->" + with + "*" + height);
 float radius = with / 4;
 canvas.drawCircle(with / 2, with / 2, radius, mPaint);
 mPaint.setColor(Color.BLUE);
 RectF oval = new RectF(with / 2 - radius, with / 2 - radius, with / 2
 + radius, with / 2 + radius); //用于定义的圆弧的形状和大小的界限
 canvas.drawArc(oval, 270, 120, true, mPaint); //根据进度画圆弧
 }
} 

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
 xmlns:tools="http://schemas.android.com/tools"
 android:layout_width="match_parent"
 android:layout_height="match_parent"
 android:orientation="vertical">

 <com.whoislcj.views.PercentView
 android:layout_width="wrap_content"
 android:layout_height="wrap_content"
 android:layout_margin="10dp" />

</LinearLayout> 

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
 xmlns:tools="http://schemas.android.com/tools"
 android:layout_width="match_parent"
 android:layout_height="match_parent"
 android:orientation="vertical">

 <com.whoislcj.views.PercentView
 android:layout_width="150dp"
 android:layout_height="150dp"
 android:layout_margin="10dp" />

</LinearLayout>