Android應用中怎么自定義一個圓形進度條

//1.畫圓環(huán)
//原點坐標
float circleX = width / 2;
float circleY = width / 2;
//半徑
float radius = width / 2 - roundWidth / 2;
//設置畫筆的屬性
paint.setColor(roundColor);
paint.setStrokeWidth(roundWidth);
paint.setStyle(Paint.Style.STROKE);
canvas.drawCircle(circleX, circleY, radius, paint);
//2.畫圓弧
RectF oval = new RectF(roundWidth/2,roundWidth/2,width-roundWidth/2,width - roundWidth/2);
paint.setColor(roundProgressColor);
canvas.drawArc(oval, 0, progress * 360 / max, false, paint);
//3.畫文本
paint.setTextSize(textSize);
paint.setColor(textColor);
paint.setStrokeWidth(0);
String text = progress * 100 / max + "%";
Rect bounds = new Rect();
paint.getTextBounds(text, 0, text.length(), bounds);
canvas.drawText(text, width / 2 - bounds.width() / 2, width / 2 + bounds.height() / 2, paint);

<declare-styleable name="RoundProgress">
 <attr name="roundColor" format="color"></attr>
 <attr name="roundProgressColor" format="color"></attr>
 <attr name="textColor" format="color"></attr>
 <attr name="roundWidth" format="dimension"></attr>
 <attr name="textSize" format="dimension"></attr>
</declare-styleable>

xmlns:atguigu=http://schemas.android.com/apk/res-auto

<com.atguigu.p2p.util.RoundProgress
  android:id="@+id/rp_home_progress"
  android:layout_width="120dp"
  android:layout_height="120dp"
  android:layout_gravity="center_horizontal"
  android:layout_marginTop="20dp"
  atguigu:roundColor="@android:color/darker_gray         <br>  atguigu:roundProgressColor="@android:color/holo_red_dark"
  atguigu:textColor="@color/text_progress"
  atguigu:roundWidth="10dp"
  atguigu:textSize="20sp"
  /> 

//1.得到所有自定義屬性的數組
TypedArray typedArray = context.obtainStyledAttributes(attrs, R.styleable.RoundProgress);
//2.獲取自定義屬性的值, 如果沒有指定取默認值
roundColor = typedArray.getColor(R.styleable.RoundProgress_roundColor, Color.RED);
roundProgressColor = typedArray.getColor(R.styleable.RoundProgress_roundProgressColor, Color.GREEN);
textColor = typedArray.getColor(R.styleable.RoundProgress_textColor, Color.GREEN);
roundWidth = typedArray.getDimension(R.styleable.RoundProgress_roundWidth, UIUtils.dp2px(10));
textSize = typedArray.getDimension(R.styleable.RoundProgress_textSize, UIUtils.dp2px(20));
//3.釋放資源數據
typedArray.recycle();