C# 其他图片格式转emf

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;
using System.Drawing.Imaging;

namespace pngtoemf
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }

        private void Save()
        {
            string filePath = @"D:\闫磊.emf";

            Bitmap bmp = new Bitmap(pictureBox1.Width, pictureBox1.Height);
            Graphics gs = Graphics.FromImage(bmp);
            Metafile mf = new Metafile(filePath, gs.GetHdc());

            Graphics g = Graphics.FromImage(mf);

            //g.FillEllipse(Brushes.Gray, 0, 0, 100, 100);
            //g.DrawEllipse(Pens.Black, 0, 0, 100, 100);
            //g.DrawArc(new Pen(Color.Red, 10), 20, 20, 60, 60, 30, 120);
            g.DrawImage(pictureBox1.Image, , );
            g.Save();
            g.Dispose();
            mf.Dispose();
        }
        private void button1_Click(object sender, EventArgs e)
        {
            pictureBox1.Load(this.textBox1.Text);
            Save();

        }
    }
}