Android使用贝塞尔曲线画心形

本文实例为大家分享了android使用贝塞尔曲线画心形的具体代码，供大家参考，具体内容如下

一开始我只是想画个圆，可画着画着就成了心形，那就将错就错

1. 创建一个activity

relativelayout container = findviewbyid(r.id.download_container);

    displaymetrics metrics = new displaymetrics();
    getwindowmanager().getdefaultdisplay().getmetrics(metrics);
    devicewidth = metrics.widthpixels;
    deviceheight = metrics.heightpixels;

    circle circle = new circle(this, devicewidth / 2, deviceheight / 2, devicewidth / 8);
    line line = new line(this, devicewidth / 2, deviceheight / 2, devicewidth / 8);
    container.addview(line);

2. 创建一个自定义的view

import android.content.context;
import android.graphics.canvas;
import android.graphics.color;
import android.graphics.paint;
import android.graphics.path;
import android.graphics.pointf;
import android.view.view;

public class line extends view {

    private paint mpaint;
    private pointf startpointf;
    private pointf endpointf;
    private pointf controlpointf1, controlpointf2;

    private pointf startpointf2;
    private pointf endpointf2;
    private pointf controlpointf3, controlpointf4;

    public line(context context, float x, float y, float radius) {
        super(context);
        double d = (2 * math.sqrt(2) - 1);
        this.startpointf = new pointf(x, y - radius);
        this.endpointf = new pointf(x, y + radius / 10);
        this.controlpointf1 = new pointf(x, (float) (y - d * radius));
        this.controlpointf2 = new pointf((float) (x + d * radius), (float) (y - d * radius));

        this.startpointf2 = new pointf(x, y - radius);
        this.endpointf2 = new pointf(x, y + radius / 10);
        this.controlpointf3 = new pointf(x, (float) (y - d * radius));
        this.controlpointf4 = new pointf((float) (x - d * radius), (float) (y - d * radius));

        this.mpaint = new paint(paint.anti_alias_flag);
        this.mpaint.setcolor(color.white);
    }

    @override
    protected void ondraw(canvas canvas) {
        super.ondraw(canvas);

        //绘制贝塞尔曲线
        path path = new path();

        path.moveto(startpointf.x, startpointf.y);
        path.cubicto(controlpointf1.x, controlpointf1.y, controlpointf2.x, controlpointf2.y, endpointf.x, endpointf.y);
        canvas.drawpath(path, mpaint);

        path.moveto(startpointf2.x, startpointf2.y);
        path.cubicto(controlpointf3.x, controlpointf3.y, controlpointf4.x, controlpointf4.y, endpointf2.x, endpointf2.y);
        canvas.drawpath(path, mpaint);
    }
}

运行效果

以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持。