C#如何设置电脑的默认打印机？

先添加对system.ManageMent的引用，//nato/EPSON LQ-1600KIII然后查找出你要设置的打印机名称，
以下事例设置为//nato/EPSON LQ-1600KIII共享打印机为默认


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

namespace WindowsApplication1
{
    public partial class Form1 : Form
    {
        private ManagementObjectSearcher query;
        private ManagementObjectCollection queryCollection;
        string _classname = "SELECT * FROM Win32_Printer";

        public Form1()
        {
            InitializeComponent();
        }

        private void button1_Click(object sender, EventArgs e)
        {
  query=new ManagementObjectSearcher(_classname);
 queryCollection=query.Get();
 foreach (ManagementObject mo in queryCollection)
    {
        if (string.Compare(mo["Name"].ToString(), @"//nato/EPSON LQ-1600KIII", true) == 0)
    {    mo.InvokeMethod("SetDefaultPrinter",null);
            break;
    }
 }
        }
}
}