ComboBox.FindStringExact Methode

Quelle:

ComboBox.cs

Quelle:

ComboBox.cs

Quelle:

ComboBox.cs

Quelle:

ComboBox.cs

Quelle:

ComboBox.cs

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

public int FindStringExact(string s);

public int FindStringExact(string? s);

member this.FindStringExact : string -> int

Public Function FindStringExact (s As String) As Integer

Parameter

Gibt zurück

Der nullbasierte Index des ersten gefundenen Elements; gibt -1 zurück, wenn keine Übereinstimmung gefunden wird, oder 0, wenn der s Parameter angibt Empty.

Beispiele

Im folgenden Codebeispiel wird veranschaulicht, wie Sie ein ComboBox Steuerelement initialisieren, indem Sie die MaxDropDownItems Eigenschaften DropDownStyle und die FindStringExact Methoden zum Durchsuchen des ComboBoxSteuerelements festlegen. Es zeigt auch die Behandlung des Ereignisses SelectedIndexChanged .

#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

Hinweise

Bei der von dieser Methode durchgeführten Suche wird die Groß-/Kleinschreibung nicht beachtet. Der s Parameter ist eine Zeichenfolge, die mit dem Text verglichen werden soll, der den Elementen in der Kombinationsfeldliste zugeordnet ist. Die Suche sucht ab dem Anfang des Texts nach einer Übereinstimmung, wobei das erste Element in der Liste zurückgegeben wird, das der angegebenen Teilzeichenfolge entspricht. Anschließend können Sie Aufgaben ausführen, z. B. das Entfernen des Elements, das den Suchtext enthält, mithilfe der Remove Methode oder Ändern des Texts des Elements. Nachdem Sie den angegebenen Text gefunden haben, müssen Sie, wenn Sie nach anderen Instanzen des Texts im ComboBoxText suchen möchten, die Version der Methode verwenden, die FindStringExact einen Parameter zum Angeben eines Startindex in der ComboBox. Wenn Sie eine teilweise Wortsuche anstelle einer exakten Wortabgleichung durchführen möchten, verwenden Sie die FindString Methode.

Quelle:

ComboBox.cs

Quelle:

ComboBox.cs

Quelle:

ComboBox.cs

Quelle:

ComboBox.cs

Quelle:

ComboBox.cs

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

public int FindStringExact(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

Parameter

Gibt zurück

Der nullbasierte Index des ersten gefundenen Elements; gibt -1 zurück, wenn keine Übereinstimmung gefunden wird, oder 0, wenn der s Parameter angibt Empty.

Ausnahmen

Beispiele

Im folgenden Codebeispiel wird veranschaulicht, wie Sie ein ComboBox Steuerelement initialisieren, indem Sie die MaxDropDownItems Eigenschaften DropDownStyle und die FindStringExact Methoden zum Durchsuchen des ComboBoxSteuerelements festlegen. Es zeigt auch die Behandlung des Ereignisses SelectedIndexChanged .

#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

Hinweise

Bei der von dieser Methode durchgeführten Suche wird die Groß-/Kleinschreibung nicht beachtet. Der s Parameter ist eine Zeichenfolge, die mit dem Text verglichen werden soll, der den Elementen in der Kombinationsfeldliste zugeordnet ist. Die Suche sucht ab dem Anfang des Texts nach einer Übereinstimmung, wobei das erste Element in der Liste zurückgegeben wird, das der angegebenen Teilzeichenfolge entspricht. Anschließend können Sie Aufgaben ausführen, z. B. das Entfernen des Elements, das den Suchtext enthält, mithilfe der Remove Methode oder Ändern des Texts des Elements. Diese Methode wird in der Regel verwendet, nachdem ein Aufruf mit der Version dieser Methode erfolgt ist, die keinen Startindex angibt. Sobald ein anfängliches Element in der Liste gefunden wurde, wird diese Methode in der Regel verwendet, um weitere Instanzen des Suchtexts zu finden, indem die Indexposition im startIndex Parameter des Elements nach der ersten gefundenen Instanz des Suchtexts angegeben wird. Wenn Sie eine teilweise Wortsuche anstelle einer exakten Wortabgleichung durchführen möchten, verwenden Sie die FindString Methode.

Die von dieser Methode durchgeführte Suche ist zirkelförmig. Obwohl die Suche nach dem startIndex Parameter am nächsten Index beginnt, wird die Suche bei 0 neu gestartet, wenn das Ende der Auflistung erreicht ist. Beachten Sie jedoch, dass eine Ausnahme ausgelöst wird, wenn der startIndex Parameter selbst dem letzten Index in der Auflistung entspricht.