Android 画布 canvas 太极图

自定义view

package cn.mf.cts;

import android.content.Context;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.graphics.Point;
import android.graphics.RectF;
import android.view.View;

/**
 * CopyRright (c)2018-2028: chanpinxue.cn
 * Project: cts
 * Module Name: Logo
 * Comments: 太极图标
 * JDK version used: JDK1.8
 * Author: jzh
 * Create Date: 2018-11-19
 * Modified By: jzh
 * Modified Date: 2018-11-19
 * Why & What is modified:
 * Version: <1.0>
 */
public class LogoView extends View {
    // 白色画笔
    private Paint whitePaint;

    // 黑色画笔
    private Paint blackPaing;

    // 画笔初始化函数
    private void initPaint() {
        whitePaint = new Paint();
        whitePaint.setAntiAlias(true);
        whitePaint.setColor(Color.WHITE);

        blackPaing = new Paint();
        blackPaing.setAntiAlias(true);
        blackPaing.setColor(Color.BLACK);
    }

    // 用户直接new一个View时会被调用
    public LogoView(Context context) {
        super(context);
        // 初始化画笔
        initPaint();
    }

    @Override
    protected void onDraw(Canvas canvas) {
        super.onDraw(canvas);
        // 画布宽度
        int width = canvas.getWidth();
        // 画布高度
        int height = canvas.getHeight();
        // 画布中心点
        Point centerPoint = new Point(width / 2, height / 2);
        // 将画布移动到中心
        canvas.translate(centerPoint.x, centerPoint.y);
        // 绘制背景色
        canvas.drawColor(Color.GRAY);

        // 绘制半黑半白
        // 太极半径
        int radius = Math.min(width, height) / 2 - 100;
        // 绘制区域
        RectF rect = new RectF(-radius, -radius, radius, radius);
        // 绘制白色半圆
        canvas.drawArc(rect, 90, 180, true, whitePaint);
        // 绘制黑色半圆
        canvas.drawArc(rect, -90, 180, true, blackPaing);

        // 绘制一黑一白两个半圆/绘制两个小圆
        int smallRadius = radius / 2;
        canvas.drawCircle(0, -smallRadius, smallRadius, whitePaint);
        canvas.drawCircle(0, smallRadius, smallRadius, blackPaing);

        // 绘制两个小圆
        // 绘制鱼眼
        canvas.drawCircle(0, -smallRadius, smallRadius / 4, blackPaing);
        canvas.drawCircle(0, smallRadius, smallRadius / 4, whitePaint);
    }
}

调用方法

// 太极Logo
LogoView logo = new LogoView(this);
// 调用方法1
setContentView(logo);

/*
// 调用方法2
LinearLayout mLayout = (LinearLayout) findViewById(R.id.linearLayout);
LinearLayout.LayoutParams params = new LinearLayout.LayoutParams(LinearLayout.LayoutParams.FILL_PARENT, LinearLayout.LayoutParams.WRAP_CONTENT);
mLayout.addView(logo, params);
*/