C# Image Resizer

using System;
using System.Windows.Forms;
using System.Drawing;
using System.IO;
class haha
{
[STAThread]
static void Main()
{
string[] s=null;
OpenFileDialog dlg = new OpenFileDialog();
dlg.Filter = "|*.jpg";
dlg.Multiselect = true;
if (dlg.ShowDialog() == DialogResult.OK)
{
s = dlg.FileNames;
}
else return;
Bitmap bit = new Bitmap(321, 241);
for (int i = 0; i < s.Length; i++)
{
Graphics.FromImage(bit).DrawImage(Image.FromFile(s[i]),0,0,320,240);
bit.Save(i + ".png");
}
MessageBox.Show("转换成功了");
}
}