C # obtain the LAN host list instance

Using System;
Using System. Drawing;
Using System. Collections;
Using System. ComponentModel;
Using System. Windows. Forms;
Using System. Data;
Using System. Net;
Using System. Threading;

Namespace WindowLanSearch
{
/// <Summary>
/// Summary of Form1.
/// </Summary>
Public class Form1: System. Windows. Forms. Form
{
Private System. Windows. Forms. TextBox textBox1;
Private System. Windows. Forms. Button button1;
Private string [,] LanHost;
Private System. Windows. Forms. ProgressBar progressBarSearch;
Private Thread [] thread;
Private System. Windows. Forms. ListView listView1;
Private System. Windows. Forms. ColumnHeader columnHeader1;
Private System. Windows. Forms. ColumnHeader columnHeader2;
Private string str;
/// <Summary>
/// Required designer variables.
/// </Summary>
Private System. ComponentModel. Container components = null;

Public Form1 ()
{
//
// Required for Windows Form Designer support
//
InitializeComponent ();
InitLanHost ();
ProgressBarSearch. Maximum = 255;

//
// TODO: add Any constructor code after InitializeComponent calls
//
}

/// <Summary>
/// Array Initialization
/// </Summary>
Private void InitLanHost ()
{
LanHost = new string [255, 2];
For (int I = 0; I <255; I ++)
{
LanHost [I, 0] = "";
LanHost [I, 1] = "";
}
}

/// <Summary>
/// Clear all resources in use.
/// </Summary>
Protected override void Dispose (bool disposing)
{
If (disposing)
{
If (components! = Null)
{
Components. Dispose ();
}
}
Base. Dispose (disposing );
}

# Region code generated by Windows Form Designer
/// <Summary>
/// The designer supports the required methods-do not use the code editor to modify
/// Content of this method.
/// </Summary>
Private void InitializeComponent ()
{
This. textBox1 = new System. Windows. Forms. TextBox ();
This. button1 = new System. Windows. Forms. Button ();
This. progressBarSearch = new System. Windows. Forms. ProgressBar ();
This. listView1 = new System. Windows. Forms. ListView ();
This. columnHeader1 = new System. Windows. Forms. ColumnHeader ();
This. columnHeader2 = new System. Windows. Forms. ColumnHeader ();
This. SuspendLayout ();
//
// TextBox1
//
This. textBox1.Location = new System. Drawing. Point (24, 40 );
This. textBox1.Multiline = true;
This. textBox1.Name = "textBox1 ";
This. textBox1.ScrollBars = System. Windows. Forms. ScrollBars. Both;
This. textBox1.Size = new System. Drawing. Size (176,296 );
This. textBox1.TabIndex = 0;
This. textBox1.Text = "";
//
// Button1
//
This. button1.Location = new System. Drawing. Point (456, 40 );
This. button1.Name = "button1 ";
This. button1.TabIndex = 1;
This. button1.Text = "start searching ";
This. button1.Click + = new System. EventHandler (this. button#click );
//
// ProgressBarSearch
//
This. progressBarSearch. Location = new System. Drawing. Point (32,360 );
This. progressBarSearch. Name = "progressBarSearch ";
This. progressBarSearch. Size = new System. Drawing. Size (490, 24 );
This. progressBarSearch. TabIndex = 2;
//
// ListView1
//
This. listView1.Columns. AddRange (new System. Windows. Forms. ColumnHeader [] {
This. columnHeader1,
This. columnHeader2 });
This. listView1.Location = new System. Drawing. Point (248, 40 );
This. listView1.Name = "listView1 ";
This. listView1.Size = new System. Drawing. Size (184,288 );
This. listView1.TabIndex = 5;
//
// ColumnHeader1
//
This. columnHeader1.Text = "dddd ";
//
// ColumnHeader2
//
This. columnHeader2.Text = "sssss ";
//
// Form1
//
This. AutoScaleBaseSize = new System. Drawing. Size (6, 14 );
This. ClientSize = new System. Drawing. Size (544,413 );
This. Controls. Add (this. listView1 );
This. Controls. Add (this. progressBarSearch );
This. Controls. Add (this. button1 );
This. Controls. Add (this. textBox1 );
This. Name = "Form1 ";
This. Text = "Form1 ";
This. ResumeLayout (false );

}
# Endregion

/// <Summary>
/// Main entry point of the application.
/// </Summary>
[STAThread]
Static void Main ()
{
Application. Run (new Form1 ());
}
Private void button#click (object sender, System. EventArgs e)
{

LanSearch ();

}
/// <Summary>
/// LAN search event
/// </Summary>
Private void LanSearch ()
{
Thread = new Thread [2, 255];

ThreadStart threadMethod;

Thread threadProgress = new Thread (new ThreadStart (progressSearch ));
ThreadProgress. Start ();

String localhost = (Dns. GetHostByName (Dns. GetHostName (). AddressList [0]. ToString (); // local host IP Address
Str = localhost. Substring (0, localhost. LastIndexOf ("."));

For (int I = 0; I <255; I ++) // create 255 threads to scan IP addresses
{
ThreadMethod = new ThreadStart (LanSearchThreadMethod );
Thread [I] = new Thread (threadMethod );
Thread [I]. Name = I. ToString ();
Thread [I]. Start ();
If (! Thread [I]. Join (100) // Thread. Join (100) I don't know if this is the case, right?
{
Thread [I]. Abort ();
}
}

GetLanHost ();
ListLanHost ();
}
/// <Summary>
/// Multi-thread Search Method
/// </Summary>
Private void LanSearchThreadMethod ()
{
Int Currently_ I = Convert. ToUInt16 (Thread. CurrentThread. Name); // The Name of the current process.

IPAddress ScanIP = IPAddress. Parse (str + "." + Convert. ToString (Currently_ I + 1); // obtain the scan IP Address
IPHostEntry ScanHost = null;
ScanHost = Dns. GetHostByAddress (ScanIP); // obtain scan IP address host information

If (ScanHost! = Null)
{
LanHost [Currently_ I, 0] = ScanIP. ToString ();
LanHost [Currently_ I, 1] = ScanHost. HostName;
}

// ProgressBarSearch. Value = progressBarSearch. Value + 1;

}
/// <Summary>
/// The Host Name and IP address list are displayed in the text box.
/// </Summary>
Private void GetLanHost ()
{
For (int I = 0; I <255; I ++)
If (LanHost [I, 0]! = "")
{
TextBox1.Text = textBox1.Text + LanHost [I, 1] + ":" + LanHost [I, 0] + "\ r \ n ";
}
}
/// <Summary>
/// Listview1 Display Search host
/// </Summary>
Private void listLanHost ()
{
ListView1.View = View. List;

ListViewItem aa;
For (int I = 0; I <255; I ++)
{
If (LanHost [I, 0]! = "")
{
Aa = new ListViewItem ();
Aa. Text = LanHost [I, 1];
Aa. Tag = LanHost [I, 0];
ListView1.Items. Add (aa );
}
}

}
/// <Summary>
/// Progress bar processing thread
/// </Summary>
Private void progressSearch ()
{
// Label1.Text = "the progress bar is only a time estimation, not a real search progress! ";
ProgressBarSearch. Value = 0;
For (int I = 0; I <255; I ++)
{
ProgressBarSearch. Value = progressBarSearch. Value + 1;
Thread. Sleep (100 );
}
}
}
}

Sorry: because the search is slow, the actual search progress is not achieved.
Do not understand: When text prompts are implemented, insert at the beginning and end of the mouse event
Private void button#click (object sender, System. EventArgs e)
{
Lab1.Text = "Start search"; // new insert
LanSearch ();
Lab1.Text = "End search"; // new insert
}
When prompted in text, lab1 cannot be displayed in time, but the "End search" is displayed only after all threads are finished.