Android学习笔记绘制几何图形

案例绘制一个安卓机器人

activity_main.xml布局就一个frameLayout，省略掉
MainActivity.java

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        //获取帧布局管理器
        FrameLayout frameLayout = findViewById(R.id.frameLayout);
        frameLayout.addView(new MyView(this));//将自定义View添加到布局管理器中
    }

MyView.java

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

public class MyView extends View {

     public MyView(Context context) {
        super(context);
    }

    @Override
    protected void onDraw(Canvas canvas) {
        super.onDraw(canvas);
        /**绘制Android机器人**/
        Paint paint = new Paint();//创建一个画笔
        paint.setAntiAlias(true);//采用锯齿功能
        paint.setColor(0xFFA4C739);//设置画笔的颜色为绿色

        //绘制机器人的头
        RectF rectF = new RectF(10,10,100,100);//定义外轮廓矩形
        rectF.offset(90,20);
        canvas.drawArc(rectF,-10,-160,false,paint);//绘制弧形
        //绘制眼睛
        paint.setColor(0xFFFFFFFF);//设置画笔为白色
        canvas.drawCircle(165,53,4,paint);//绘制圆
        canvas.drawCircle(125,53,4,paint);//绘制圆
        //绘制天线
        paint.setColor(0xFFA4C739);
        paint.setStrokeWidth(2);//设置笔触的宽度
        canvas.drawLine(110,15,
                125,35,paint);
        canvas.drawLine(180,15,
                165,35,paint);//绘制线

        //绘制身体
        canvas.drawRect(100,75,
                190,150,paint);
        RectF rectF_body = new RectF(100,140,
                190,160);
        canvas.drawRoundRect(rectF_body,10,
                10,paint);//绘制圆角矩形

        //绘制胳膊
        RectF rectF_arm = new RectF(75,75,
                95,140);
        canvas.drawRoundRect(rectF_arm,10,
                10,paint);//绘制圆角矩形
        rectF_arm.offset(120,0);
        canvas.drawRoundRect(rectF_arm,10,10,paint);//绘制圆角矩形
        //绘制腿
        RectF rectF_leg = new RectF(115,150,
                135,200);
        canvas.drawRoundRect(rectF_leg,10,10,paint);
        rectF_leg.offset(40,0);
        canvas.drawRoundRect(rectF_leg,10,10,paint);
     }
}

效果: