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SystemInformation.Network Property

Gets a value indicating whether a network connection is present.

Namespace: System.Windows.Forms
Assembly: System.Windows.Forms (in system.windows.forms.dll)

public static bool Network { get; }
/** @property */
public static boolean get_Network ()

public static function get Network () : boolean

Not applicable.

Property Value

true if a network connection is present; otherwise, false.

The Network property indicates whether the system has a currently established network connection.

NoteNote:

This property always returns true on all Windows platforms supported by the .NET Framework. Use the System.Net.NetworkInformation namespace to retrieve more accurate network status.

The following code example lists all properties of the SystemInformation class in a ListBox and displays the current value of the property in a TextBox when a list item selected.

using System;
using System.Collections;
using System.ComponentModel;
using System.Drawing;
using System.Reflection;
using System.Windows.Forms;

namespace SystemInfoBrowser
{
    public class SystemInfoBrowserForm : System.Windows.Forms.Form
    {
        private System.Windows.Forms.ListBox listBox1;
        private System.Windows.Forms.TextBox textBox1;        
        
        public SystemInfoBrowserForm()
	    {
            this.SuspendLayout();
            InitForm();
            
            // Add each property of the SystemInformation class to the list box.
            Type t = typeof(System.Windows.Forms.SystemInformation);            
            PropertyInfo[] pi = t.GetProperties();            
            for( int i=0; i<pi.Length; i++ )
                listBox1.Items.Add( pi[i].Name );            
            textBox1.Text = "The SystemInformation class has "+pi.Length.ToString()+" properties.\r\n";

            // Configure the list item selected handler for the list box to invoke a 
            // method that displays the value of each property.
            listBox1.SelectedIndexChanged += new EventHandler(listBox1_SelectedIndexChanged);
            this.ResumeLayout(false);
	    }
		
        private void listBox1_SelectedIndexChanged(object sender, EventArgs e)
        {
            // Return if no list item is selected.
            if( listBox1.SelectedIndex == -1 ) return;
            // Get the property name from the list item.
            string propname = listBox1.Text;
            
            if( propname == "PowerStatus" )
            {
                // Cycle and display the values of each property of the PowerStatus property.
                textBox1.Text += "\r\nThe value of the PowerStatus property is:";                                
                Type t = typeof(System.Windows.Forms.PowerStatus);
                PropertyInfo[] pi = t.GetProperties();            
                for( int i=0; i<pi.Length; i++ )
                {
                    object propval = pi[i].GetValue(SystemInformation.PowerStatus, null);            
                    textBox1.Text += "\r\n    PowerStatus."+pi[i].Name+" is: "+propval.ToString();
                }
            }
            else
            {
                // Display the value of the selected property of the SystemInformation type.
                Type t = typeof(System.Windows.Forms.SystemInformation);
                PropertyInfo[] pi = t.GetProperties();            
                PropertyInfo prop = null;
                for( int i=0; i<pi.Length; i++ )
                    if( pi[i].Name == propname )
                    {
                        prop = pi[i];
                        break;           
                    }
                object propval = prop.GetValue(null, null);            
                textBox1.Text += "\r\nThe value of the "+propname+" property is: "+propval.ToString();
            }
        }

        private void InitForm()
        {
            // Initialize the form settings
            this.listBox1 = new System.Windows.Forms.ListBox();
            this.textBox1 = new System.Windows.Forms.TextBox();            
            this.listBox1.Anchor = ((System.Windows.Forms.AnchorStyles)((((System.Windows.Forms.AnchorStyles.Top | System.Windows.Forms.AnchorStyles.Bottom) 
                | System.Windows.Forms.AnchorStyles.Left) | System.Windows.Forms.AnchorStyles.Right)));
            this.listBox1.Location = new System.Drawing.Point(8, 16);
            this.listBox1.Size = new System.Drawing.Size(172, 496);
            this.listBox1.TabIndex = 0;            
            this.textBox1.Anchor = ((System.Windows.Forms.AnchorStyles)(((System.Windows.Forms.AnchorStyles.Top | System.Windows.Forms.AnchorStyles.Bottom) 
                | System.Windows.Forms.AnchorStyles.Right)));
            this.textBox1.Location = new System.Drawing.Point(188, 16);
            this.textBox1.Multiline = true;
            this.textBox1.ScrollBars = System.Windows.Forms.ScrollBars.Vertical;           
            this.textBox1.Size = new System.Drawing.Size(420, 496);
            this.textBox1.TabIndex = 1;            
            this.ClientSize = new System.Drawing.Size(616, 525);            
            this.Controls.Add(this.textBox1);
            this.Controls.Add(this.listBox1);            
            this.Text = "Select a SystemInformation property to get the value of";                   
        }

        [STAThread]
        static void Main() 
        {
            Application.Run(new SystemInfoBrowserForm());
        }
    }
}

package SystemInfoBrowser;

import System.*;
import System.Collections.*;
import System.ComponentModel.*;
import System.Drawing.*;
import System.Reflection.*;
import System.Windows.Forms.*;

public class SystemInfoBrowserForm extends System.Windows.Forms.Form
{
    private System.Windows.Forms.ListBox listBox1;
    private System.Windows.Forms.TextBox textBox1;

    public SystemInfoBrowserForm()
    {
        this.SuspendLayout();
        InitForm();
        // Add each property of the SystemInformation class to the list box.
        Type t = System.Windows.Forms.SystemInformation.class.ToType();
        PropertyInfo pi[] = t.GetProperties();
        for (int i = 0; i < pi.length; i++) {
            listBox1.get_Items().Add(pi[i].get_Name());
        }
        textBox1.set_Text("The SystemInformation class has "
            + ((Int32)pi.length).ToString() + " properties.\r\n");
        // Configure the list item selected handler for the list box to invoke
        // a method that displays the value of each property.
        listBox1.add_SelectedIndexChanged(
            new EventHandler(listBox1_SelectedIndexChanged));
        this.ResumeLayout(false);
    } //SystemInfoBrowserForm

    private void listBox1_SelectedIndexChanged(Object sender, EventArgs e)
    {
        // Return if no list item is selected.
        if (listBox1.get_SelectedIndex() == -1) {
            return;
        }
        // Get the property name from the list item.
        String propname = listBox1.get_Text();

        if (propname.Equals("PowerStatus")) {
            // Cycle and display the values of each property of the
            // PowerStatus property.
            textBox1.set_Text(textBox1.get_Text()
                + "\r\nThe value of the PowerStatus property is:");
            Type t = System.Windows.Forms.PowerStatus.class.ToType();
            PropertyInfo pi[] = t.GetProperties();
            for (int i = 0; i < pi.length; i++) {
                Object propval = pi[i].GetValue(
                    SystemInformation.get_PowerStatus(), null);
                textBox1.set_Text(textBox1.get_Text()
                    + "\r\n    PowerStatus." + pi[i].get_Name()
                    + " is: " + propval.ToString());
            }
        }
        else {
            // Display the value of the selected property of the
            // SystemInformation type.
            Type t = System.Windows.Forms.SystemInformation.class.ToType();
            PropertyInfo pi[] = t.GetProperties();
            PropertyInfo prop = null;
            for (int i = 0; i < pi.length; i++) {
                if (pi[i].get_Name().Equals(propname)) {
                    prop = pi[i];
                    break;
                }
            }
            Object propval = prop.GetValue(null, null);
            textBox1.set_Text(textBox1.get_Text() + "\r\nThe value of the "
                + propname + " property is: " + propval.ToString());
        }
    } //listBox1_SelectedIndexChanged

    private void InitForm()
    {
        // Initialize the form settings
        this.listBox1 = new System.Windows.Forms.ListBox();
        this.textBox1 = new System.Windows.Forms.TextBox();
        this.listBox1.set_Anchor((System.Windows.Forms.AnchorStyles)
            (System.Windows.Forms.AnchorStyles.Top
            | System.Windows.Forms.AnchorStyles.Bottom
            | System.Windows.Forms.AnchorStyles.Left
            | System.Windows.Forms.AnchorStyles.Right));
        this.listBox1.set_Location(new System.Drawing.Point(8, 16));
        this.listBox1.set_Size(new System.Drawing.Size(172, 496));
        this.listBox1.set_TabIndex(0);
        this.textBox1.set_Anchor((System.Windows.Forms.AnchorStyles)
            (System.Windows.Forms.AnchorStyles.Top
            | System.Windows.Forms.AnchorStyles.Bottom
            | System.Windows.Forms.AnchorStyles.Right));
        this.textBox1.set_Location(new System.Drawing.Point(188, 16));
        this.textBox1.set_Multiline(true);
        this.textBox1.set_ScrollBars(System.Windows.Forms.ScrollBars.Vertical);
        this.textBox1.set_Size(new System.Drawing.Size(420, 496));
        this.textBox1.set_TabIndex(1);
        this.set_ClientSize(new System.Drawing.Size(616, 525));
        this.get_Controls().Add(this.textBox1);
        this.get_Controls().Add(this.listBox1);
        this.set_Text("Select a SystemInformation property to get the value of");
    } //InitForm

    /** @attribute STAThread()
     */
    public static void main(String[] args)
    {
        Application.Run(new SystemInfoBrowserForm());
    } //main
} //SystemInfoBrowserForm

Windows 98, Windows Server 2000 SP4, Windows CE, Windows Millennium Edition, Windows Mobile for Pocket PC, Windows Mobile for Smartphone, Windows Server 2003, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP SP2, Windows XP Starter Edition

The Microsoft .NET Framework 3.0 is supported on Windows Vista, Microsoft Windows XP SP2, and Windows Server 2003 SP1.

.NET Framework

Supported in: 3.0, 2.0, 1.1, 1.0

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