LinkArea Estrutura

  • Referência

Definição

Namespace:
System.Windows.Forms
Assembly:
System.Windows.Forms.dll

Representa uma área dentro de um controle LinkLabel que representa um hiperlink dentro do controle.

public value class LinkArea
public value class LinkArea : IEquatable<System::Windows::Forms::LinkArea>
[System.ComponentModel.TypeConverter(typeof(System.Windows.Forms.LinkArea+LinkAreaConverter))]
[System.Serializable]
public struct LinkArea
[System.ComponentModel.TypeConverter(typeof(System.Windows.Forms.LinkArea+LinkAreaConverter))]
[System.Serializable]
public struct LinkArea : IEquatable<System.Windows.Forms.LinkArea>
[<System.ComponentModel.TypeConverter(typeof(System.Windows.Forms.LinkArea+LinkAreaConverter))>]
[<System.Serializable>]
type LinkArea = struct
Public Structure LinkArea
Public Structure LinkArea
Implements IEquatable(Of LinkArea)
Herança
Object
ValueType
LinkArea
Atributos
TypeConverterAttribute SerializableAttribute
Implementações
IEquatable<LinkArea>

Exemplos

O exemplo de código a seguir demonstra o uso da LinkLabel classe , com várias LinkArea seções definidas, para exibir um rótulo em um formulário. O exemplo demonstra a configuração das AutoSizepropriedades , LinkBehavior, DisabledLinkColor, LinkColore VisitedLinkColor para personalizar a aparência do LinkLabel. O primeiro LinkArea é especificado usando a LinkLabel.LinkArea propriedade . Links adicionais são adicionados ao LinkLabel usando o LinkLabel.LinkCollection.Add método . O exemplo manipula o LinkClicked evento iniciando o navegador da Web para hiperlinks e exibindo um MessageBox para outros links.

#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 ref class Form1: public System::Windows::Forms::Form
{
private:
   System::Windows::Forms::LinkLabel^ linkLabel1;

public:
   Form1()
   {
      
      // Create the LinkLabel.
      this->linkLabel1 = gcnew 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 += gcnew 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[ 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" );
         this->linkLabel1->Links[ 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 );
      array<System::Windows::Forms::Control^>^temp0 = {this->linkLabel1};
      this->Controls->AddRange( temp0 );
      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 = dynamic_cast<String^>(e->Link->LinkData);
      
      // If the value looks like a URL, navigate to it.
      // Otherwise, display it in a message box.
      if ( nullptr != target && target->StartsWith( "www" ) )
      {
         System::Diagnostics::Process::Start( target );
      }
      else
      {
         MessageBox::Show( "Item clicked: {0}", target );
      }
   }
};

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

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);
        }
    }
}

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

    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 (target IsNot Nothing) AndAlso (target.StartsWith("www")) Then
            System.Diagnostics.Process.Start(target)
        Else
            MessageBox.Show(("Item clicked: " + target))
        End If

    End Sub

End Class

Comentários

Há duas maneiras de adicionar um hiperlink ao texto de um LinkLabel controle. Você pode acessar o Add método da LinkLabel.LinkCollection classe por meio da Links propriedade do LinkLabel para adicionar vários hiperlinks ao texto do controle. Se você só precisar adicionar um único hiperlink ao texto do controle, poderá usar a LinkArea propriedade do LinkLabel. Essa propriedade aceita um LinkArea que define o local do hiperlink dentro do texto do controle. Quando um hiperlink é especificado usando a LinkArea propriedade , a área de link é adicionada ao da LinkLabel.LinkCollection mesma maneira que adicionar o link usando o Add método do LinkLabel.LinkCollection.

A Length propriedade especifica o número de caracteres dentro do texto do LinkLabel a ser incluído na área de link. A Start propriedade especifica o primeiro caractere no texto de controle a ser incluído no hiperlink. Se você quiser determinar se um específico LinkArea está vazio, use a IsEmpty propriedade em vez de verificar os valores das Start propriedades e Length .

Construtores

LinkArea(Int32, Int32)

Inicializa uma nova instância da classe LinkArea.

Propriedades

IsEmpty

Obtém um valor que indica se o LinkArea está vazio.
Length

Obtém ou define o número de caracteres na área do link.
Start

Obtém ou define o local inicial da área do link no texto do LinkLabel.

Métodos

Equals(LinkArea)

Indica se o objeto atual é igual a outro objeto do mesmo tipo.
Equals(Object)

Determina se este LinkArea é igual ao objeto especificado.
GetHashCode()

Retorna o código hash para a instância.
ToString()

Retorna o nome do tipo totalmente qualificado dessa instância.

Operadores

Equality(LinkArea, LinkArea)

Retorna um valor que indica se duas instâncias da classe LinkArea são iguais.
Inequality(LinkArea, LinkArea)

Retorna um valor que indica se duas instâncias da classe LinkArea não são iguais.

Aplica-se a

Confira também