package com.bwei.test.zidingyiview2;import android.content.Context;import android.graphics.Canvas;import android.graphics.Color;import android.graphics.Paint;import android.util.AttributeSet;import android.view.View;public class MyView extends View { private Context mcontext; private Paint mpaint; public MyView(Context context) {  super(context); } public MyView(Context context, AttributeSet attrs) {  super(context, attrs); } public MyView(Context context, AttributeSet attrs, int defStyleAttr) {  super(context, attrs, defStyleAttr);  this.mcontext = context; } @Override protected void onDraw(Canvas canvas) {  super.onDraw(canvas);//  得到屏幕寬高  float wi = canvas.getWidth() / 2;  float he = canvas.getHeight() / 2;//  創(chuàng)建第一個(gè)畫(huà)筆  Paint pa = new Paint();//  上色  pa.setColor(Color.GREEN);//  顯示圓邊  pa.setAntiAlias(true);//  設(shè)置空心圓環(huán)  pa.setStyle(Paint.Style.STROKE);//  設(shè)置圓環(huán)寬度  pa.setStrokeWidth(6);  Paint pa2 = new Paint();  pa2.setColor(Color.BLUE);  pa2.setAntiAlias(true);  Paint pa3 = new Paint();  pa3.setColor(Color.BLACK);  pa3.setAntiAlias(true);//  畫(huà)什么圓  canvas.drawCircle(wi-85, he-85, 80, pa2);  canvas.drawCircle(wi, he, 100, pa);  canvas.drawCircle(wi+110, he+110, 120, pa3); }}

<?xml version="1.0" encoding="utf-8"?><RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android" xmlns:tools="http://schemas.android.com/tools" android:id="@+id/activity_main" android:layout_width="match_parent" android:layout_height="match_parent" android:paddingBottom="@dimen/activity_vertical_margin" android:paddingLeft="@dimen/activity_horizontal_margin" android:paddingRight="@dimen/activity_horizontal_margin" android:paddingTop="@dimen/activity_vertical_margin" tools:context="com.bwei.test.zidingyiview2.MainActivity"> <com.bwei.test.zidingyiview2.MyView  android:layout_width="wrap_content"  android:layout_height="wrap_content"/></RelativeLayout>