Visual C＃通过信史服务实现网络信息传送的具体实现步骤 ：

using System ;
using System.Drawing ;
using System.Collections ;
using System.ComponentModel ;
using System.Windows.Forms ;
using System.Data ;
using System.Runtime.InteropServices ;
//申明WinAPI函数需要使用到此命名空间

private void InitializeComponent ( )
{
　this.textBox1 = new System.Windows.Forms.TextBox ( ) ;
　this.textBox2 = new System.Windows.Forms.TextBox ( ) ;
　this.button1 = new System.Windows.Forms.Button ( ) ;
　this.label1 = new System.Windows.Forms.Label ( ) ;
　this.label2 = new System.Windows.Forms.Label ( ) ;
　this.SuspendLayout ( ) ;
　this.textBox1.Location = new System.Drawing.Point ( 124 , 58 ) ;
　this.textBox1.Name = "textBox1" ;
　this.textBox1.Size = new System.Drawing.Size ( 212 , 21 ) ;
　this.textBox1.TabIndex = 0 ;
　this.textBox1.Text = "" ;
　this.textBox2.Location = new System.Drawing.Point ( 124 , 126 ) ;
　this.textBox2.Multiline = true ;
　this.textBox2.Name = "textBox2" ;
　this.textBox2.Size = new System.Drawing.Size ( 212 , 82 ) ;
　this.textBox2.TabIndex = 1 ;
　this.textBox2.Text = "" ;
　this.button1.Location = new System.Drawing.Point ( 122 , 232 ) ;
　this.button1.Name = "button1" ;
　this.button1.Size = new System.Drawing.Size ( 106 , 36 ) ;
　this.button1.TabIndex = 3 ;
　this.button1.Text = "发送" ;
　this.button1.Click += new System.EventHandler ( this.button1_Click ) ;
　this.label1.Location = new System.Drawing.Point ( 8 , 66 ) ;
　this.label1.Name = "label1" ;
　this.label1.Size = new System.Drawing.Size ( 132 , 23 ) ;
　this.label1.TabIndex = 4 ;
　this.label1.Text = "IP地址或计算机名：" ;
　this.label2.Location = new System.Drawing.Point ( 78 , 134 ) ;
　this.label2.Name = "label2" ;
　this.label2.Size = new System.Drawing.Size ( 46 , 23 ) ;
　this.label2.TabIndex = 5 ;
　this.label2.Text = "内容：" ;
　this.AutoScaleBaseSize = new System.Drawing.Size ( 6 , 14 ) ;
　this.ClientSize = new System.Drawing.Size ( 356 , 297 ) ;
　this.Controls.Add ( this.button1 ) ;
　this.Controls.Add ( this.textBox2 ) ;
　this.Controls.Add ( this.textBox1 ) ;
　this.Controls.Add ( this.label2 ) ;
　this.Controls.Add ( this.label1 ) ;
　this.FormBorderStyle = System.Windows.Forms.FormBorderStyle.FixedSingle ;
　this.MaximizeBox = false ;
　this.Name = "Form1" ;
　this.Text = "Visual C＃ 实现通讯信使" ;
　this.ResumeLayout ( false ) ;
}

图04：【Visual C＃实现通讯信使】项目的设计界面

private void button1_Click ( object sender , System.EventArgs e )
{
　byte [ ] bBuffer = System.Text.Encoding.Unicode.GetBytes ( textBox2.Text );
　int nRet = NetMessageBufferSend ( null , textBox1.Text , null , textBox2.Text , textBox2.Text.Length * 2 + 2 ) ;
}

[DllImport ( "Netapi32" , CharSet = CharSet.Unicode ) ]
public static extern int NetMessageBufferSend (
　string servername , //服务器名称，为NULL
　string fromname , //接收方名称，可为IP或计算机名称
　string msgname , //信息名称，为NULL
　string buf , //信息
　int buflen ) ; //信息长度