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LinkLabel Class

Represents a Windows label control that can display hyperlinks.

For a list of all members of this type, see LinkLabel Members.

System.Object
   System.MarshalByRefObject
      System.ComponentModel.Component
         System.Windows.Forms.Control
            System.Windows.Forms.Label
               System.Windows.Forms.LinkLabel

[Visual Basic]
Public Class LinkLabel
   Inherits Label
   Implements IButtonControl
[C#]
public class LinkLabel : Label, IButtonControl
[C++]
public __gc class LinkLabel : public Label, IButtonControl
[JScript]
public class LinkLabel extends Label implements IButtonControl

Thread Safety

Any public static (Shared in Visual Basic) members of this type are thread safe. Any instance members are not guaranteed to be thread safe.

Remarks

The LinkLabel control is similar to a Label control with the exception that it can display a hyperlink. Multiple hyperlinks can be specified in the text of the control. Each hyperlink can perform a different task within an application. For example, you can use a hyperlink to display a Web site in Microsoft Internet Explorer or to load a log file associated with an application.

Each hyperlink displayed in the LinkLabel control is an instance of the LinkLabel.Link class. The LinkLabel.Link class defines display information, state, and location of the hyperlink. In addition, the LinkData property of the LinkLabel.Link class enables you to associate information, such as a URL to display, with the hyperlink. When a user clicks a hyperlink within the control, the LinkClicked event is raised, and the LinkLabel.Link object representing the hyperlink that was clicked is passed as part of the LinkLabelLinkClickedEventArgs object that is passed as a parameter to the event handler. You can use this object to obtain the LinkLabel.Link object associated with the hyperlink that was clicked by the user. All hyperlinks contained within the LinkLabel control are stored in the LinkLabel.LinkCollection class instance for the control.

There are two ways to add a hyperlink to the LinkLabel control. The quickest way is to specify a LinkArea object and assign it to the LinkArea property. This enables you to specify a single hyperlink within the text of the control. To add multiple hyperlinks, you can use the Add method of the LinkLabel.LinkCollection class by accessing the collection through the Links property.

When a LinkLabel control is created, a default hyperlink that contains all the text within the LinkLabel control is added to the LinkLabel.LinkCollection. You can override this default link by specifying a new link area with the LinkArea property, or specify a link using the Add method of the LinkLabel.LinkCollection. You can also remove the default hyperlink by using the Remove method of the LinkLabel.LinkCollection class.

The LinkLabel provides a number of properties that enable you to define the display appearance of hyperlinks in the control. The ActiveLinkColor, DisabledLinkColor, LinkColor, and VisitedLinkColor properties define the colors used when displaying a hyperlink in various states. The LinkBehavior property defines the display of the underline that is associated with a hyperlink.

Example

[Visual Basic, C#, C++] The following example demonstrates using the LinkLabel class, with multiple LinkArea sections defined, to display a label on a form. The example demonstrates setting the AutoSize, LinkBehavior, DisabledLinkColor, LinkColor, and VisitedLinkColor properties to customize the look of the LinkLabel. The first LinkArea is specified using the LinkLabel.LinkArea property. Additional links are added to the LinkLabel using the LinkCollection.Add method. The example handles the LinkClicked event by starting the Web browser for hyperlinks, and displaying a MessageBox for other links.

[Visual Basic] 
Imports System
Imports System.Drawing
Imports System.Windows.Forms

Public NotInheritable Class Form1
    Inherits System.Windows.Forms.Form

    Friend WithEvents LinkLabel1 As System.Windows.Forms.LinkLabel

    <System.STAThread()> _
    Public Shared Sub Main()
        System.Windows.Forms.Application.Run(New Form1)
    End Sub 'Main

    Public Sub New()
        MyBase.New()


        Me.LinkLabel1 = New System.Windows.Forms.LinkLabel

        ' Configure the LinkLabel's size and location. Specify that the
        ' size should be automatically determined by the content.
        Me.linkLabel1.Location = New System.Drawing.Point(34, 56) 
        Me.linkLabel1.Size = New System.Drawing.Size(224, 16) 
        Me.linkLabel1.AutoSize = True 

        ' Configure the appearance.
        ' Set the DisabledLinkColor so that a disabled link will show up against the form's background.
        Me.linkLabel1.DisabledLinkColor = System.Drawing.Color.Red 
        Me.linkLabel1.VisitedLinkColor = System.Drawing.Color.Blue 
        Me.linkLabel1.LinkBehavior = System.Windows.Forms.LinkBehavior.HoverUnderline 
        Me.linkLabel1.LinkColor = System.Drawing.Color.Navy 
        
        Me.linkLabel1.TabIndex = 0 
        Me.linkLabel1.TabStop = True 
        
        ' Identify what the first Link is.
        Me.linkLabel1.LinkArea = New System.Windows.Forms.LinkArea(0, 8)

        ' Identify that the first link is visited already.
        Me.linkLabel1.Links(0).Visited = true
        
        ' Set the Text property to a string.
        Me.linkLabel1.Text = "Register Online.  Visit Microsoft.  Visit MSN."

        ' Create new links using the Add method of the LinkCollection class.
        ' Underline the appropriate words in the LinkLabel's Text property.
        ' The words 'Register', 'Microsoft', and 'MSN' will 
        ' all be underlined and behave as hyperlinks.

        ' First check that the Text property is long enough to accommodate
        ' the desired hyperlinked areas.  If it's not, don't add hyperlinks.
        If Me.LinkLabel1.Text.Length >= 45 Then
            Me.LinkLabel1.Links(0).LinkData = "Register"
            Me.LinkLabel1.Links.Add(24, 9, "www.microsoft.com")
            Me.LinkLabel1.Links.Add(42, 3, "www.msn.com")
            ' The second link is disabled and will appear as red.
            Me.linkLabel1.Links(1).Enabled = False
        End If

        ' Set up how the form should be displayed and adds the controls to the form.
        Me.ClientSize = New System.Drawing.Size(292, 266)
        Me.Controls.AddRange(New System.Windows.Forms.Control() {Me.LinkLabel1})
        Me.Text = "Link Label Example"
    End Sub

    Private Sub linkLabel1_LinkClicked(ByVal sender As Object, _
                ByVal e As System.Windows.Forms.LinkLabelLinkClickedEventArgs) Handles LinkLabel1.LinkClicked

        ' Determine which link was clicked within the LinkLabel.
        Me.LinkLabel1.Links(LinkLabel1.Links.IndexOf(e.Link)).Visited = True

        ' Displays the appropriate link based on the value of the LinkData property of the Link object.
        Dim target As String = CType(e.Link.LinkData, String)

        ' If the value looks like a URL, navigate to it.
        ' Otherwise, display it in a message box.
        If (Nothing <> target) And (target.StartsWith("www")) Then
            System.Diagnostics.Process.Start(target)
        Else
            MessageBox.Show(("Item clicked: " + target))
        End If

    End Sub

End Class

[C#] 
using System;
using System.Drawing;
using System.Windows.Forms;

public class Form1 : System.Windows.Forms.Form
{
    private System.Windows.Forms.LinkLabel linkLabel1;
    
    [STAThread]
    static void Main() 
    {
        Application.Run(new Form1());
    }

    public Form1()
    {
        // Create the LinkLabel.
        this.linkLabel1 = new System.Windows.Forms.LinkLabel();

        // Configure the LinkLabel's size and location. Specify that the
        // size should be automatically determined by the content.
        this.linkLabel1.Location = new System.Drawing.Point(34, 56);
        this.linkLabel1.Size = new System.Drawing.Size(224, 16);
        this.linkLabel1.AutoSize = true;

        // Configure the appearance. 
        // Set the DisabledLinkColor so that a disabled link will show up against the form's background.
        this.linkLabel1.DisabledLinkColor = System.Drawing.Color.Red;
        this.linkLabel1.VisitedLinkColor = System.Drawing.Color.Blue;
        this.linkLabel1.LinkBehavior = System.Windows.Forms.LinkBehavior.HoverUnderline;
        this.linkLabel1.LinkColor = System.Drawing.Color.Navy;
        
        this.linkLabel1.TabIndex = 0;
        this.linkLabel1.TabStop = true;
        

        // Add an event handler to do something when the links are clicked.
        this.linkLabel1.LinkClicked += new System.Windows.Forms.LinkLabelLinkClickedEventHandler(this.linkLabel1_LinkClicked);

        // Identify what the first Link is.
        this.linkLabel1.LinkArea = new System.Windows.Forms.LinkArea(0, 8);

        // Identify that the first link is visited already.
        this.linkLabel1.Links[0].Visited = true;
        
        // Set the Text property to a string.
        this.linkLabel1.Text = "Register Online.  Visit Microsoft.  Visit MSN.";

        // Create new links using the Add method of the LinkCollection class.
        // Underline the appropriate words in the LinkLabel's Text property.
        // The words 'Register', 'Microsoft', and 'MSN' will 
        // all be underlined and behave as hyperlinks.

        // First check that the Text property is long enough to accommodate
        // the desired hyperlinked areas.  If it's not, don't add hyperlinks.
        if(this.linkLabel1.Text.Length >= 45)
        {
            this.linkLabel1.Links[0].LinkData = "Register";
            this.linkLabel1.Links.Add(24, 9, "www.microsoft.com");
            this.linkLabel1.Links.Add(42, 3, "www.msn.com");
        //  The second link is disabled and will appear as red.
            this.linkLabel1.Links[1].Enabled = false;
        }
        
        // Set up how the form should be displayed and add the controls to the form.
        this.ClientSize = new System.Drawing.Size(292, 266);
        this.Controls.AddRange(new System.Windows.Forms.Control[] {this.linkLabel1});
        this.Text = "Link Label Example";
    }

    private void linkLabel1_LinkClicked(object sender, System.Windows.Forms.LinkLabelLinkClickedEventArgs e)
    {
        // Determine which link was clicked within the LinkLabel.
        this.linkLabel1.Links[linkLabel1.Links.IndexOf(e.Link)].Visited = true;

        // Display the appropriate link based on the value of the 
        // LinkData property of the Link object.
        string target = e.Link.LinkData as string;

        // If the value looks like a URL, navigate to it.
        // Otherwise, display it in a message box.
        if(null != target && target.StartsWith("www"))
        {
            System.Diagnostics.Process.Start(target);
        }
        else
        {    
            MessageBox.Show("Item clicked: " + target);
        }
    }
}

[C++] 
#using <mscorlib.dll>
#using <System.dll>
#using <System.Windows.Forms.dll>
#using <System.Drawing.dll>

using namespace System;
using namespace System::Drawing;
using namespace System::Windows::Forms;

public __gc class Form1 : public System::Windows::Forms::Form {
private:
   System::Windows::Forms::LinkLabel*  linkLabel1;
public:
   Form1() {
      // Create the LinkLabel.
      this->linkLabel1 = new System::Windows::Forms::LinkLabel();

      // Configure the LinkLabel's size and location. Specify that the
      // size should be automatically determined by the content.
      this->linkLabel1->Location =  System::Drawing::Point(34, 56);
      this->linkLabel1->Size =  System::Drawing::Size(224, 16);
      this->linkLabel1->AutoSize = true;

      // Configure the appearance.
      this->linkLabel1->DisabledLinkColor = System::Drawing::Color::Red;
      this->linkLabel1->VisitedLinkColor = System::Drawing::Color::Blue;
      this->linkLabel1->LinkBehavior = System::Windows::Forms::LinkBehavior::HoverUnderline;
      this->linkLabel1->LinkColor = System::Drawing::Color::Navy;

      this->linkLabel1->TabIndex = 0;
      this->linkLabel1->TabStop = true;


      // Add an event handler to do something when the links are clicked.
      this->linkLabel1->LinkClicked += new System::Windows::Forms::LinkLabelLinkClickedEventHandler(this, &Form1::linkLabel1_LinkClicked);

      // Identify what the first Link is.
      this->linkLabel1->LinkArea =  System::Windows::Forms::LinkArea(0, 8);

      // Identify that the first link is visited already.
      this->linkLabel1->Links->Item[0]->Visited = true;

      // Set the Text property to a String*.
      this->linkLabel1->Text = S"Register Online.  Visit Microsoft.  Visit MSN.";

      // Create new links using the Add method of the LinkCollection class.
      // Underline the appropriate words in the LinkLabel's Text property.
      // The words 'Register', 'Microsoft', and 'MSN' will
      // all be underlined and behave as hyperlinks.

      // First check that the Text property is long enough to accommodate
      // the desired hyperlinked areas.  If it's not, don't add hyperlinks.
      if (this->linkLabel1->Text->Length >= 45) {
         this->linkLabel1->Links->Item[0]->LinkData = S"Register";
         this->linkLabel1->Links->Add(24, 9, S"www.microsoft.com");
         this->linkLabel1->Links->Add(42, 3, S"www.msn.com");
         this->linkLabel1->Links->Item[1]->Enabled = false;
      }

      // Set up how the form should be displayed and add the controls to the form.
      this->ClientSize =  System::Drawing::Size(292, 266);

      System::Windows::Forms::Control* temp0 [] = {this->linkLabel1};

      this->Controls->AddRange(temp0);
      this->Text = S"Link Label Example";
   }

private:
   void linkLabel1_LinkClicked(Object* /*sender*/, System::Windows::Forms::LinkLabelLinkClickedEventArgs* e) {
      // Determine which link was clicked within the LinkLabel.
      this->linkLabel1->Links->Item[linkLabel1->Links->IndexOf(e->Link)]->Visited = true;

      // Display the appropriate link based on the value of the
      // LinkData property of the Link Object*.
      String* target = dynamic_cast<String*>(e->Link->LinkData);

      // If the value looks like a URL, navigate to it.
      // Otherwise, display it in a message box.
      if (0 != target && target->StartsWith(S"www")) {
         System::Diagnostics::Process::Start(target);
      } else {
         MessageBox::Show(S"Item clicked: {0}", target);
      }
   }
};

[STAThread]
int main() {
   Application::Run(new Form1());
}

[JScript] No example is available for JScript. To view a Visual Basic, C#, or C++ example, click the Language Filter button Language Filter in the upper-left corner of the page.

Requirements

Namespace: System.Windows.Forms

Platforms: Windows 98, Windows NT 4.0, Windows Millennium Edition, Windows 2000, Windows XP Home Edition, Windows XP Professional, Windows Server 2003 family

Assembly: System.Windows.Forms (in System.Windows.Forms.dll)

See Also

LinkLabel Members | System.Windows.Forms Namespace | Label | LinkLabelLinkClickedEventArgs | LinkLabel.Link | LinkLabel.LinkCollection

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