Android studio 自定义view 画圆

package day.com.day01_viewall;import android.content.Context;import android.graphics.Canvas;import android.graphics.Color;import android.graphics.Paint;import android.support.annotation.Nullable;import android.util.AttributeSet;import android.view.MotionEvent;import android.view.View;public class VirtualKeyView extends  View{   private Paint mPaint;    Context mContext;    public VirtualKeyView(Context context) {        super(context);    }    public VirtualKeyView(Context context, @Nullable AttributeSet attrs) {        super(context, attrs);    }    public VirtualKeyView(Context context, @Nullable AttributeSet attrs, int defStyleAttr) {        super(context, attrs, defStyleAttr);        this.mContext=context;    }    //测量    @Override    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {        super.onMeasure(widthMeasureSpec, heightMeasureSpec);    }    //绘制    @Override    protected void onDraw(Canvas canvas) {        //画圆        //初始化画笔 文字        Paint pa = new Paint();        //圆        Paint pa1 = new Paint();        float wi = canvas.getWidth()/2;        float he = canvas.getHeight()/2;        pa.setColor(Color.BLACK);        pa.setARGB(255, 199, 33, 56);        pa1.setColor(Color.BLUE);        pa.setAntiAlias(true);                       //设置画笔为无锯齿        pa1.setAntiAlias(true);        canvas.drawColor(Color.YELLOW);        canvas.drawCircle(30, 30,60, pa);        canvas.drawCircle(wi, he, 60, pa1);        canvas.drawText("1508A大神养成记", wi, he, pa);        super.onDraw(canvas);    }    //定位    @Override    protected void onLayout(boolean changed, int left, int top, int right, int bottom) {        super.onLayout(changed, left, top, right, bottom);    }    //监听    @Override    public boolean onTouchEvent(MotionEvent event) {        return super.onTouchEvent(event);    }}

<com.bwie.test.huayuan.Zidingy        android:layout_width="wrap_content"        android:layout_height="wrap_content" />