ComboBox.FindStringExact Metoda

Definice

Obor názvů:

System.Windows.Forms

Sestavení:

System.Windows.Forms.dll

Najde položku, která přesně odpovídá zadanému řetězci.

Přetížení

Name	Description
FindStringExact(String)	Najde první položku v poli se seznamem, která odpovídá zadanému řetězci.
FindStringExact(String, Int32)	Najde první položku za zadaným indexem, který odpovídá zadanému řetězci.

FindStringExact(String)

Zdroj:

ComboBox.cs

Najde první položku v poli se seznamem, která odpovídá zadanému řetězci.

public:
 int FindStringExact(System::String ^ s);

public int FindStringExact(string? s);

member this.FindStringExact : string -> int

Public Function FindStringExact (s As String) As Integer

Parametry

s

String

Hledá se String .

Návraty

Int32

Index založený na nule první nalezené položky; vrátí -1 pokud nebyla nalezena žádná shoda, nebo 0, pokud s parametr určuje Empty.

Příklady

Následující příklad kódu ukazuje, jak inicializovat ComboBox ovládací prvek nastavením MaxDropDownItems a DropDownStyle vlastnosti a pomocí FindStringExact metod pro vyhledávání ComboBox. Zobrazuje také zpracování SelectedIndexChanged události.

#using <System.Drawing.dll>
#using <System.dll>
#using <System.Windows.Forms.dll>

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

public ref class Form1: public System::Windows::Forms::Form
{
public:
   Form1() : Form()
   {
      InitializeComboBox();
      InitializeTextBox();
      this->Label1 = gcnew System::Windows::Forms::Label;
      this->SuspendLayout();
      this->Label1->Location = System::Drawing::Point( 8, 24 );
      this->Label1->Name = "Label1";
      this->Label1->Size = System::Drawing::Size( 120, 32 );
      this->Label1->TabIndex = 1;
      this->Label1->Text = "Use drop-down to choose a name:";
      this->Label1->TextAlign = System::Drawing::ContentAlignment::MiddleRight;
      this->ClientSize = System::Drawing::Size( 292, 266 );
      this->Controls->Add( this->Label1 );
      this->Name = "Form1";
      this->Text = "Form1";
      this->ResumeLayout( false );
   }

internal:
   System::Windows::Forms::Label ^ Label1;

   // Declare and initialize the text box.
internal:
   // This text box text will be update programmatically. The user is not 
   // allowed to update it, so the ReadOnly property is set to true.
   System::Windows::Forms::TextBox^ TextBox1;

private:
   void InitializeTextBox()
   {
      this->TextBox1 = gcnew System::Windows::Forms::TextBox;
      this->TextBox1->ScrollBars = ScrollBars::Vertical;
      this->TextBox1->Location = System::Drawing::Point( 64, 128 );
      this->TextBox1->Multiline = true;
      this->TextBox1->Name = "TextBox1";
      this->TextBox1->ReadOnly = true;
      this->TextBox1->Size = System::Drawing::Size( 184, 120 );
      this->TextBox1->TabIndex = 4;
      this->TextBox1->Text = "Employee and Number of Awards:";
      this->Controls->Add( this->TextBox1 );
   }

   // Declare comboBox1 as a ComboBox.
internal:
   System::Windows::Forms::ComboBox^ ComboBox1;

private:
   // This method initializes the combo box, adding a large string array
   // but limiting the drop-down size to six rows so the combo box doesn't 
   // cover other controls when it expands.
   void InitializeComboBox()
   {
      this->ComboBox1 = gcnew System::Windows::Forms::ComboBox;
      array<String^>^ employees = {"Hamilton, David","Hensien, Kari",
         "Hammond, Maria","Harris, Keith","Henshaw, Jeff D.",
         "Hanson, Mark","Harnpadoungsataya, Sariya",
         "Harrington, Mark","Harris, Keith","Hartwig, Doris",
         "Harui, Roger","Hassall, Mark","Hasselberg, Jonas",
         "Harnpadoungsataya, Sariya","Henshaw, Jeff D.",
         "Henshaw, Jeff D.","Hensien, Kari","Harris, Keith",
         "Henshaw, Jeff D.","Hensien, Kari","Hasselberg, Jonas",
         "Harrington, Mark","Hedlund, Magnus","Hay, Jeff",
         "Heidepriem, Brandon D."};
      ComboBox1->Items->AddRange( employees );
      this->ComboBox1->Location = System::Drawing::Point( 136, 32 );
      this->ComboBox1->IntegralHeight = false;
      this->ComboBox1->MaxDropDownItems = 5;
      this->ComboBox1->DropDownStyle = ComboBoxStyle::DropDownList;
      this->ComboBox1->Name = "ComboBox1";
      this->ComboBox1->Size = System::Drawing::Size( 136, 81 );
      this->ComboBox1->TabIndex = 0;
      this->Controls->Add( this->ComboBox1 );
      
      // Associate the event-handling method with the 
      // SelectedIndexChanged event.
      this->ComboBox1->SelectedIndexChanged +=
         gcnew System::EventHandler( this, &Form1::ComboBox1_SelectedIndexChanged );
   }

private:
   // This method is called when the user changes his or her selection.
   // It searches for all occurrences of the selected employee's
   // name in the Items array and adds the employee's name and 
   // the number of occurrences to TextBox1.Text.

   // CAUTION   This code exposes a known bug: If the index passed to the 
   // FindStringExact(searchString, index) method is the last index 
   // of the array, the code throws an exception.
   void ComboBox1_SelectedIndexChanged( Object^ sender,
      System::EventArgs^ e )
   {
      ComboBox^ comboBox = (ComboBox^)(sender);
      
      // Save the selected employee's name, because we will remove
      // the employee's name from the list.
      String^ selectedEmployee = (String^)(ComboBox1->SelectedItem);

      int count = 0;
      int resultIndex = -1;
      
      // Call the FindStringExact method to find the first 
      // occurrence in the list.
      resultIndex = ComboBox1->FindStringExact( selectedEmployee );
      
      // Remove the name as it is found, and increment the found count. 
      // Then call the FindStringExact method again, passing in the 
      // index of the current found item so the search starts there 
      // instead of at the beginning of the list.
      while ( resultIndex != -1 )
      {
         ComboBox1->Items->RemoveAt( resultIndex );
         count += 1;
         resultIndex = ComboBox1->FindStringExact( selectedEmployee,
            resultIndex );
      }

      TextBox1->Text = TextBox1->Text + "\r\n" + selectedEmployee + ": " +
         count;
   }
};

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

using System.Windows.Forms;

public class Form1:
    System.Windows.Forms.Form

{
    public Form1() : base()
    {        
        InitializeComboBox();
        InitializeTextBox();
        this.Label1 = new System.Windows.Forms.Label();
        this.SuspendLayout();
        this.Label1.Location = new System.Drawing.Point(8, 24);
        this.Label1.Name = "Label1";
        this.Label1.Size = new System.Drawing.Size(120, 32);
        this.Label1.TabIndex = 1;
        this.Label1.Text = "Use drop-down to choose a name:";
        this.Label1.TextAlign = System.Drawing.ContentAlignment.MiddleRight;
        this.ClientSize = new System.Drawing.Size(292, 266);
        this.Controls.Add(this.Label1);
        this.Name = "Form1";
        this.Text = "Form1";
        this.ResumeLayout(false);
    }

    public static void Main()
    {
        Application.Run(new Form1());
    }

    internal System.Windows.Forms.Label Label1;


    // Declare and initialize the text box.
    // This text box text will be update programmatically. The user is not 
    // allowed to update it, so the ReadOnly property is set to true.
    internal System.Windows.Forms.TextBox TextBox1;

    private void InitializeTextBox()
    {
        this.TextBox1 = new System.Windows.Forms.TextBox();
        this.TextBox1.ScrollBars = ScrollBars.Vertical;
        this.TextBox1.Location = new System.Drawing.Point(64, 128);
        this.TextBox1.Multiline = true;
        this.TextBox1.Name = "TextBox1";
        this.TextBox1.ReadOnly = true;
        this.TextBox1.Size = new System.Drawing.Size(184, 120);
        this.TextBox1.TabIndex = 4;
        this.TextBox1.Text = "Employee and Number of Awards:";
        this.Controls.Add(this.TextBox1);
    }

    // Declare comboBox1 as a ComboBox.
    internal System.Windows.Forms.ComboBox ComboBox1;
    
    // This method initializes the combo box, adding a large string array
    // but limiting the drop-down size to six rows so the combo box doesn't 
    // cover other controls when it expands.
    private void InitializeComboBox()
    {
        this.ComboBox1 = new System.Windows.Forms.ComboBox();
        string[] employees = new string[]{"Hamilton, David", "Hensien, Kari",
                "Hammond, Maria", "Harris, Keith", "Henshaw, Jeff D.", 
                "Hanson, Mark", "Harnpadoungsataya, Sariya", 
                "Harrington, Mark", "Harris, Keith", "Hartwig, Doris", 
                "Harui, Roger", "Hassall, Mark", "Hasselberg, Jonas", 
                "Harnpadoungsataya, Sariya", "Henshaw, Jeff D.", 
                "Henshaw, Jeff D.", "Hensien, Kari", "Harris, Keith", 
                "Henshaw, Jeff D.", "Hensien, Kari", "Hasselberg, Jonas",
                "Harrington, Mark", "Hedlund, Magnus", "Hay, Jeff", 
                "Heidepriem, Brandon D."};

        ComboBox1.Items.AddRange(employees);
        this.ComboBox1.Location = new System.Drawing.Point(136, 32);
        this.ComboBox1.IntegralHeight = false;
        this.ComboBox1.MaxDropDownItems = 5;
        this.ComboBox1.DropDownStyle = ComboBoxStyle.DropDownList;
        this.ComboBox1.Name = "ComboBox1";
        this.ComboBox1.Size = new System.Drawing.Size(136, 81);
        this.ComboBox1.TabIndex = 0;
        this.Controls.Add(this.ComboBox1);
        
        // Associate the event-handling method with the 
        // SelectedIndexChanged event.
        this.ComboBox1.SelectedIndexChanged += 
            new System.EventHandler(ComboBox1_SelectedIndexChanged);
    }

    // This method is called when the user changes his or her selection.
    // It searches for all occurrences of the selected employee's
    // name in the Items array and adds the employee's name and 
    // the number of occurrences to TextBox1.Text.

    // CAUTION   This code exposes a known bug: If the index passed to the 
    // FindStringExact(searchString, index) method is the last index 
    // of the array, the code throws an exception.
    private void ComboBox1_SelectedIndexChanged(object sender, 
        System.EventArgs e)
    {

        ComboBox comboBox = (ComboBox) sender;

        // Save the selected employee's name, because we will remove
        // the employee's name from the list.
        string selectedEmployee = (string) ComboBox1.SelectedItem;

        int count = 0;
        int resultIndex = -1;

        // Call the FindStringExact method to find the first 
        // occurrence in the list.
        resultIndex = ComboBox1.FindStringExact(selectedEmployee);

        // Remove the name as it is found, and increment the found count. 
        // Then call the FindStringExact method again, passing in the 
        // index of the current found item so the search starts there 
        // instead of at the beginning of the list.
        while (resultIndex!=-1)
        {
            ComboBox1.Items.RemoveAt(resultIndex);
            count += 1;
            resultIndex = ComboBox1.FindStringExact(selectedEmployee, 
                resultIndex);
        }
        // Update the text in Textbox1.
        TextBox1.Text = TextBox1.Text+ "\r\n" + selectedEmployee + ": "
            + count;
    }
}

Imports System.Windows.Forms

Public Class Form1
    Inherits System.Windows.Forms.Form

    Public Sub New()
        MyBase.New()
        InitializeComboBox()
        InitializeTextBox()
        Me.Label1 = New System.Windows.Forms.Label
        Me.SuspendLayout()
        Me.Label1.Location = New System.Drawing.Point(8, 24)
        Me.Label1.Name = "Label1"
        Me.Label1.Size = New System.Drawing.Size(120, 32)
        Me.Label1.TabIndex = 1
        Me.Label1.Text = "Use drop-down to choose a name:"
        Me.Label1.TextAlign = System.Drawing.ContentAlignment.MiddleRight
        Me.ClientSize = New System.Drawing.Size(292, 266)
        Me.Controls.Add(Me.Label1)
        Me.Name = "Form1"
        Me.Text = "Form1"
        Me.ResumeLayout(False)
    End Sub

    Shared Sub Main()
        Application.Run(New Form1)
    End Sub

   
    Friend WithEvents Label1 As System.Windows.Forms.Label
    
    
    

    ' Declare and initialize the text box.
    ' This text box text will be update programmatically. The user is not 
    ' allowed to update it, so the ReadOnly property is set to true.
    Friend WithEvents TextBox1 As System.Windows.Forms.TextBox

    Private Sub InitializeTextBox()
        Me.TextBox1 = New System.Windows.Forms.TextBox
        Me.TextBox1.ScrollBars = ScrollBars.Vertical
        Me.TextBox1.Location = New System.Drawing.Point(64, 128)
        Me.TextBox1.Multiline = True
        Me.TextBox1.Name = "TextBox1"
        Me.TextBox1.ReadOnly = True
        Me.TextBox1.Size = New System.Drawing.Size(184, 120)
        Me.TextBox1.TabIndex = 4
        Me.TextBox1.Text = "Employee and Number of Awards:"
        Me.Controls.Add(Me.TextBox1)
    End Sub


    ' Declare comboBox1 as a ComboBox.
    Friend WithEvents ComboBox1 As System.Windows.Forms.ComboBox

    ' This method initializes the combo box, adding a large string 
    ' array but limiting the drop-down size to six rows so the combo box
    ' doesn't cover other controls when it expands.
    Private Sub InitializeComboBox()
        Me.ComboBox1 = New System.Windows.Forms.ComboBox
        Dim employees() As String = New String() {"Hamilton, David", _
            "Hensien, Kari", "Hammond, Maria", "Harris, Keith", _
            "Henshaw, Jeff D.", "Hanson, Mark", "Harnpadoungsataya, Sariya", _
            "Harrington, Mark", "Harris, Keith", "Hartwig, Doris", _
            "Harui, Roger", "Hassall, Mark", "Hasselberg, Jonas", _
            "Harnpadoungsataya, Sariya", "Henshaw, Jeff D.", "Henshaw, Jeff D.", _
            "Hensien, Kari", "Harris, Keith", "Henshaw, Jeff D.", _
            "Hensien, Kari", "Hasselberg, Jonas", "Harrington, Mark", _
            "Hedlund, Magnus", "Hay, Jeff", "Heidepriem, Brandon D."}

        ComboBox1.Items.AddRange(employees)
        Me.ComboBox1.Location = New System.Drawing.Point(136, 32)
        Me.ComboBox1.IntegralHeight = False
        Me.ComboBox1.MaxDropDownItems = 5
        Me.ComboBox1.DropDownStyle = ComboBoxStyle.DropDown
        Me.ComboBox1.Name = "ComboBox1"
        Me.ComboBox1.Size = New System.Drawing.Size(136, 81)
        Me.ComboBox1.TabIndex = 0
        Me.Controls.Add(Me.ComboBox1)
    End Sub



    ' This method is called when the user changes his or her selection.
    ' It searches for all occurrences of the selected employee's
    ' name in the Items array and adds the employee's name and 
    ' the number of occurrences to TextBox1.Text.

    ' CAUTION   This code exposes a known bug: If the index passed to the 
    ' FindStringExact(searchString, index) method is the last index 
    ' of the array, the code throws an exception.
    Private Sub ComboBox1_SelectedIndexChanged(ByVal sender As Object, _
        ByVal e As System.EventArgs) Handles ComboBox1.SelectedIndexChanged

        Dim comboBox As comboBox = CType(sender, comboBox)

        ' Save the selected employee's name, because we will remove
        ' the employee's name from the list.
        Dim selectedEmployee = CType(ComboBox1.SelectedItem, String)

        Dim count As Integer = 0
        Dim resultIndex As Integer = -1

        ' Call the FindStringExact method to find the first 
        ' occurrence in the list.
        resultIndex = ComboBox1.FindStringExact(ComboBox1.SelectedItem)

        ' Remove the name as it is found, and increment the found count. 
        ' Then call the FindStringExact method again, passing in the index of the
        ' current found item so the search starts there instead of 
        ' at the beginning of the list.
        While (resultIndex <> -1)
            ComboBox1.Items.RemoveAt(resultIndex)
            count += 1
            resultIndex = ComboBox1.FindStringExact _
            (selectedEmployee, resultIndex)
        End While

        ' Update the text in Textbox1.
        TextBox1.Text = TextBox1.Text & Microsoft.VisualBasic.vbCrLf _
            & selectedEmployee & ": " & count
    End Sub

End Class

Poznámky

Vyhledávání prováděné touto metodou nerozlišuje malá a velká písmena. Parametr s je řetězec pro porovnání s textem přidruženým k položkám v seznamu polí se seznamem. Hledání hledá shodu od začátku textu a vrátí první položku v seznamu, která odpovídá zadanému podřetězdci. Pak můžete provádět úlohy, například odebrat položku obsahující hledaný text pomocí Remove metody nebo změnit text položky. Jakmile najdete zadaný text, pokud chcete vyhledat jiné instance textu v souboru ComboBox, musíte použít verzi FindStringExact metody, která poskytuje parametr pro určení počátečního indexu ComboBoxv rámci . Pokud chcete místo přesné shody slov provést částečné hledání slov, použijte metodu FindString .

FindStringExact(String, Int32)

Zdroj:

ComboBox.cs

Najde první položku za zadaným indexem, který odpovídá zadanému řetězci.

public:
 int FindStringExact(System::String ^ s, int startIndex);

public int FindStringExact(string? s, int startIndex);

member this.FindStringExact : string * int -> int

Public Function FindStringExact (s As String, startIndex As Integer) As Integer

Parametry

s

String

Hledá se String .

startIndex

Int32

Index položky založený na nule před první položkou, která se má prohledávat. Nastavte na -1 hledání od začátku ovládacího prvku.

Návraty

Int32

Index založený na nule první nalezené položky; vrátí -1 pokud nebyla nalezena žádná shoda, nebo 0, pokud s parametr určuje Empty.

Výjimky

ArgumentOutOfRangeException

Je startIndex menší než -1.

nebo

Rovná startIndex se poslednímu indexu v kolekci.

Příklady

Následující příklad kódu ukazuje, jak inicializovat ComboBox ovládací prvek nastavením MaxDropDownItems a DropDownStyle vlastnosti a pomocí FindStringExact metod pro vyhledávání ComboBox. Zobrazuje také zpracování SelectedIndexChanged události.

#using <System.Drawing.dll>
#using <System.dll>
#using <System.Windows.Forms.dll>

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

public ref class Form1: public System::Windows::Forms::Form
{
public:
   Form1() : Form()
   {
      InitializeComboBox();
      InitializeTextBox();
      this->Label1 = gcnew System::Windows::Forms::Label;
      this->SuspendLayout();
      this->Label1->Location = System::Drawing::Point( 8, 24 );
      this->Label1->Name = "Label1";
      this->Label1->Size = System::Drawing::Size( 120, 32 );
      this->Label1->TabIndex = 1;
      this->Label1->Text = "Use drop-down to choose a name:";
      this->Label1->TextAlign = System::Drawing::ContentAlignment::MiddleRight;
      this->ClientSize = System::Drawing::Size( 292, 266 );
      this->Controls->Add( this->Label1 );
      this->Name = "Form1";
      this->Text = "Form1";
      this->ResumeLayout( false );
   }

internal:
   System::Windows::Forms::Label ^ Label1;

   // Declare and initialize the text box.
internal:
   // This text box text will be update programmatically. The user is not 
   // allowed to update it, so the ReadOnly property is set to true.
   System::Windows::Forms::TextBox^ TextBox1;

private:
   void InitializeTextBox()
   {
      this->TextBox1 = gcnew System::Windows::Forms::TextBox;
      this->TextBox1->ScrollBars = ScrollBars::Vertical;
      this->TextBox1->Location = System::Drawing::Point( 64, 128 );
      this->TextBox1->Multiline = true;
      this->TextBox1->Name = "TextBox1";
      this->TextBox1->ReadOnly = true;
      this->TextBox1->Size = System::Drawing::Size( 184, 120 );
      this->TextBox1->TabIndex = 4;
      this->TextBox1->Text = "Employee and Number of Awards:";
      this->Controls->Add( this->TextBox1 );
   }

   // Declare comboBox1 as a ComboBox.
internal:
   System::Windows::Forms::ComboBox^ ComboBox1;

private:
   // This method initializes the combo box, adding a large string array
   // but limiting the drop-down size to six rows so the combo box doesn't 
   // cover other controls when it expands.
   void InitializeComboBox()
   {
      this->ComboBox1 = gcnew System::Windows::Forms::ComboBox;
      array<String^>^ employees = {"Hamilton, David","Hensien, Kari",
         "Hammond, Maria","Harris, Keith","Henshaw, Jeff D.",
         "Hanson, Mark","Harnpadoungsataya, Sariya",
         "Harrington, Mark","Harris, Keith","Hartwig, Doris",
         "Harui, Roger","Hassall, Mark","Hasselberg, Jonas",
         "Harnpadoungsataya, Sariya","Henshaw, Jeff D.",
         "Henshaw, Jeff D.","Hensien, Kari","Harris, Keith",
         "Henshaw, Jeff D.","Hensien, Kari","Hasselberg, Jonas",
         "Harrington, Mark","Hedlund, Magnus","Hay, Jeff",
         "Heidepriem, Brandon D."};
      ComboBox1->Items->AddRange( employees );
      this->ComboBox1->Location = System::Drawing::Point( 136, 32 );
      this->ComboBox1->IntegralHeight = false;
      this->ComboBox1->MaxDropDownItems = 5;
      this->ComboBox1->DropDownStyle = ComboBoxStyle::DropDownList;
      this->ComboBox1->Name = "ComboBox1";
      this->ComboBox1->Size = System::Drawing::Size( 136, 81 );
      this->ComboBox1->TabIndex = 0;
      this->Controls->Add( this->ComboBox1 );
      
      // Associate the event-handling method with the 
      // SelectedIndexChanged event.
      this->ComboBox1->SelectedIndexChanged +=
         gcnew System::EventHandler( this, &Form1::ComboBox1_SelectedIndexChanged );
   }

private:
   // This method is called when the user changes his or her selection.
   // It searches for all occurrences of the selected employee's
   // name in the Items array and adds the employee's name and 
   // the number of occurrences to TextBox1.Text.

   // CAUTION   This code exposes a known bug: If the index passed to the 
   // FindStringExact(searchString, index) method is the last index 
   // of the array, the code throws an exception.
   void ComboBox1_SelectedIndexChanged( Object^ sender,
      System::EventArgs^ e )
   {
      ComboBox^ comboBox = (ComboBox^)(sender);
      
      // Save the selected employee's name, because we will remove
      // the employee's name from the list.
      String^ selectedEmployee = (String^)(ComboBox1->SelectedItem);

      int count = 0;
      int resultIndex = -1;
      
      // Call the FindStringExact method to find the first 
      // occurrence in the list.
      resultIndex = ComboBox1->FindStringExact( selectedEmployee );
      
      // Remove the name as it is found, and increment the found count. 
      // Then call the FindStringExact method again, passing in the 
      // index of the current found item so the search starts there 
      // instead of at the beginning of the list.
      while ( resultIndex != -1 )
      {
         ComboBox1->Items->RemoveAt( resultIndex );
         count += 1;
         resultIndex = ComboBox1->FindStringExact( selectedEmployee,
            resultIndex );
      }

      TextBox1->Text = TextBox1->Text + "\r\n" + selectedEmployee + ": " +
         count;
   }
};

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

using System.Windows.Forms;

public class Form1:
    System.Windows.Forms.Form

{
    public Form1() : base()
    {        
        InitializeComboBox();
        InitializeTextBox();
        this.Label1 = new System.Windows.Forms.Label();
        this.SuspendLayout();
        this.Label1.Location = new System.Drawing.Point(8, 24);
        this.Label1.Name = "Label1";
        this.Label1.Size = new System.Drawing.Size(120, 32);
        this.Label1.TabIndex = 1;
        this.Label1.Text = "Use drop-down to choose a name:";
        this.Label1.TextAlign = System.Drawing.ContentAlignment.MiddleRight;
        this.ClientSize = new System.Drawing.Size(292, 266);
        this.Controls.Add(this.Label1);
        this.Name = "Form1";
        this.Text = "Form1";
        this.ResumeLayout(false);
    }

    public static void Main()
    {
        Application.Run(new Form1());
    }

    internal System.Windows.Forms.Label Label1;


    // Declare and initialize the text box.
    // This text box text will be update programmatically. The user is not 
    // allowed to update it, so the ReadOnly property is set to true.
    internal System.Windows.Forms.TextBox TextBox1;

    private void InitializeTextBox()
    {
        this.TextBox1 = new System.Windows.Forms.TextBox();
        this.TextBox1.ScrollBars = ScrollBars.Vertical;
        this.TextBox1.Location = new System.Drawing.Point(64, 128);
        this.TextBox1.Multiline = true;
        this.TextBox1.Name = "TextBox1";
        this.TextBox1.ReadOnly = true;
        this.TextBox1.Size = new System.Drawing.Size(184, 120);
        this.TextBox1.TabIndex = 4;
        this.TextBox1.Text = "Employee and Number of Awards:";
        this.Controls.Add(this.TextBox1);
    }

    // Declare comboBox1 as a ComboBox.
    internal System.Windows.Forms.ComboBox ComboBox1;
    
    // This method initializes the combo box, adding a large string array
    // but limiting the drop-down size to six rows so the combo box doesn't 
    // cover other controls when it expands.
    private void InitializeComboBox()
    {
        this.ComboBox1 = new System.Windows.Forms.ComboBox();
        string[] employees = new string[]{"Hamilton, David", "Hensien, Kari",
                "Hammond, Maria", "Harris, Keith", "Henshaw, Jeff D.", 
                "Hanson, Mark", "Harnpadoungsataya, Sariya", 
                "Harrington, Mark", "Harris, Keith", "Hartwig, Doris", 
                "Harui, Roger", "Hassall, Mark", "Hasselberg, Jonas", 
                "Harnpadoungsataya, Sariya", "Henshaw, Jeff D.", 
                "Henshaw, Jeff D.", "Hensien, Kari", "Harris, Keith", 
                "Henshaw, Jeff D.", "Hensien, Kari", "Hasselberg, Jonas",
                "Harrington, Mark", "Hedlund, Magnus", "Hay, Jeff", 
                "Heidepriem, Brandon D."};

        ComboBox1.Items.AddRange(employees);
        this.ComboBox1.Location = new System.Drawing.Point(136, 32);
        this.ComboBox1.IntegralHeight = false;
        this.ComboBox1.MaxDropDownItems = 5;
        this.ComboBox1.DropDownStyle = ComboBoxStyle.DropDownList;
        this.ComboBox1.Name = "ComboBox1";
        this.ComboBox1.Size = new System.Drawing.Size(136, 81);
        this.ComboBox1.TabIndex = 0;
        this.Controls.Add(this.ComboBox1);
        
        // Associate the event-handling method with the 
        // SelectedIndexChanged event.
        this.ComboBox1.SelectedIndexChanged += 
            new System.EventHandler(ComboBox1_SelectedIndexChanged);
    }

    // This method is called when the user changes his or her selection.
    // It searches for all occurrences of the selected employee's
    // name in the Items array and adds the employee's name and 
    // the number of occurrences to TextBox1.Text.

    // CAUTION   This code exposes a known bug: If the index passed to the 
    // FindStringExact(searchString, index) method is the last index 
    // of the array, the code throws an exception.
    private void ComboBox1_SelectedIndexChanged(object sender, 
        System.EventArgs e)
    {

        ComboBox comboBox = (ComboBox) sender;

        // Save the selected employee's name, because we will remove
        // the employee's name from the list.
        string selectedEmployee = (string) ComboBox1.SelectedItem;

        int count = 0;
        int resultIndex = -1;

        // Call the FindStringExact method to find the first 
        // occurrence in the list.
        resultIndex = ComboBox1.FindStringExact(selectedEmployee);

        // Remove the name as it is found, and increment the found count. 
        // Then call the FindStringExact method again, passing in the 
        // index of the current found item so the search starts there 
        // instead of at the beginning of the list.
        while (resultIndex!=-1)
        {
            ComboBox1.Items.RemoveAt(resultIndex);
            count += 1;
            resultIndex = ComboBox1.FindStringExact(selectedEmployee, 
                resultIndex);
        }
        // Update the text in Textbox1.
        TextBox1.Text = TextBox1.Text+ "\r\n" + selectedEmployee + ": "
            + count;
    }
}

Imports System.Windows.Forms

Public Class Form1
    Inherits System.Windows.Forms.Form

    Public Sub New()
        MyBase.New()
        InitializeComboBox()
        InitializeTextBox()
        Me.Label1 = New System.Windows.Forms.Label
        Me.SuspendLayout()
        Me.Label1.Location = New System.Drawing.Point(8, 24)
        Me.Label1.Name = "Label1"
        Me.Label1.Size = New System.Drawing.Size(120, 32)
        Me.Label1.TabIndex = 1
        Me.Label1.Text = "Use drop-down to choose a name:"
        Me.Label1.TextAlign = System.Drawing.ContentAlignment.MiddleRight
        Me.ClientSize = New System.Drawing.Size(292, 266)
        Me.Controls.Add(Me.Label1)
        Me.Name = "Form1"
        Me.Text = "Form1"
        Me.ResumeLayout(False)
    End Sub

    Shared Sub Main()
        Application.Run(New Form1)
    End Sub

   
    Friend WithEvents Label1 As System.Windows.Forms.Label
    
    
    

    ' Declare and initialize the text box.
    ' This text box text will be update programmatically. The user is not 
    ' allowed to update it, so the ReadOnly property is set to true.
    Friend WithEvents TextBox1 As System.Windows.Forms.TextBox

    Private Sub InitializeTextBox()
        Me.TextBox1 = New System.Windows.Forms.TextBox
        Me.TextBox1.ScrollBars = ScrollBars.Vertical
        Me.TextBox1.Location = New System.Drawing.Point(64, 128)
        Me.TextBox1.Multiline = True
        Me.TextBox1.Name = "TextBox1"
        Me.TextBox1.ReadOnly = True
        Me.TextBox1.Size = New System.Drawing.Size(184, 120)
        Me.TextBox1.TabIndex = 4
        Me.TextBox1.Text = "Employee and Number of Awards:"
        Me.Controls.Add(Me.TextBox1)
    End Sub


    ' Declare comboBox1 as a ComboBox.
    Friend WithEvents ComboBox1 As System.Windows.Forms.ComboBox

    ' This method initializes the combo box, adding a large string 
    ' array but limiting the drop-down size to six rows so the combo box
    ' doesn't cover other controls when it expands.
    Private Sub InitializeComboBox()
        Me.ComboBox1 = New System.Windows.Forms.ComboBox
        Dim employees() As String = New String() {"Hamilton, David", _
            "Hensien, Kari", "Hammond, Maria", "Harris, Keith", _
            "Henshaw, Jeff D.", "Hanson, Mark", "Harnpadoungsataya, Sariya", _
            "Harrington, Mark", "Harris, Keith", "Hartwig, Doris", _
            "Harui, Roger", "Hassall, Mark", "Hasselberg, Jonas", _
            "Harnpadoungsataya, Sariya", "Henshaw, Jeff D.", "Henshaw, Jeff D.", _
            "Hensien, Kari", "Harris, Keith", "Henshaw, Jeff D.", _
            "Hensien, Kari", "Hasselberg, Jonas", "Harrington, Mark", _
            "Hedlund, Magnus", "Hay, Jeff", "Heidepriem, Brandon D."}

        ComboBox1.Items.AddRange(employees)
        Me.ComboBox1.Location = New System.Drawing.Point(136, 32)
        Me.ComboBox1.IntegralHeight = False
        Me.ComboBox1.MaxDropDownItems = 5
        Me.ComboBox1.DropDownStyle = ComboBoxStyle.DropDown
        Me.ComboBox1.Name = "ComboBox1"
        Me.ComboBox1.Size = New System.Drawing.Size(136, 81)
        Me.ComboBox1.TabIndex = 0
        Me.Controls.Add(Me.ComboBox1)
    End Sub



    ' This method is called when the user changes his or her selection.
    ' It searches for all occurrences of the selected employee's
    ' name in the Items array and adds the employee's name and 
    ' the number of occurrences to TextBox1.Text.

    ' CAUTION   This code exposes a known bug: If the index passed to the 
    ' FindStringExact(searchString, index) method is the last index 
    ' of the array, the code throws an exception.
    Private Sub ComboBox1_SelectedIndexChanged(ByVal sender As Object, _
        ByVal e As System.EventArgs) Handles ComboBox1.SelectedIndexChanged

        Dim comboBox As comboBox = CType(sender, comboBox)

        ' Save the selected employee's name, because we will remove
        ' the employee's name from the list.
        Dim selectedEmployee = CType(ComboBox1.SelectedItem, String)

        Dim count As Integer = 0
        Dim resultIndex As Integer = -1

        ' Call the FindStringExact method to find the first 
        ' occurrence in the list.
        resultIndex = ComboBox1.FindStringExact(ComboBox1.SelectedItem)

        ' Remove the name as it is found, and increment the found count. 
        ' Then call the FindStringExact method again, passing in the index of the
        ' current found item so the search starts there instead of 
        ' at the beginning of the list.
        While (resultIndex <> -1)
            ComboBox1.Items.RemoveAt(resultIndex)
            count += 1
            resultIndex = ComboBox1.FindStringExact _
            (selectedEmployee, resultIndex)
        End While

        ' Update the text in Textbox1.
        TextBox1.Text = TextBox1.Text & Microsoft.VisualBasic.vbCrLf _
            & selectedEmployee & ": " & count
    End Sub

End Class

Poznámky

Vyhledávání prováděné touto metodou nerozlišuje malá a velká písmena. Parametr s je řetězec pro porovnání s textem přidruženým k položkám v seznamu polí se seznamem. Hledání hledá shodu od začátku textu a vrátí první položku v seznamu, která odpovídá zadanému podřetězdci. Pak můžete provádět úlohy, například odebrat položku obsahující hledaný text pomocí Remove metody nebo změnit text položky. Tato metoda se obvykle používá po volání pomocí verze této metody, která nezadá počáteční index. Jakmile se v seznamu najde počáteční položka, tato metoda se obvykle používá k vyhledání dalších instancí hledaného textu zadáním pozice indexu v startIndex parametru položky za první nalezenou instancí vyhledávacího textu. Pokud chcete místo přesné shody slov provést částečné hledání slov, použijte metodu FindString .

Hledání prováděné touto metodou je kruhové. Přestože hledání začíná na dalším indexu za parametrem startIndex , vyhledávání se restartuje při dosažení konce kolekce na 0. Všimněte si však, že pokud startIndex se samotný parametr rovná poslednímu indexu v kolekci, vyvolá se výjimka.