CheckState CheckState CheckState CheckState Enum

Definition

Specifies the state of a control, such as a check box, that can be checked, unchecked, or set to an indeterminate state.

public enum class CheckState
public enum CheckState
type CheckState = 
Public Enum CheckState
Inheritance

Fields

Checked Checked Checked Checked 1

The control is checked.

Indeterminate Indeterminate Indeterminate Indeterminate 2

The control is indeterminate. An indeterminate control generally has a shaded appearance.

Unchecked Unchecked Unchecked Unchecked 0

The control is unchecked.

Examples

The following code example demonstrates the use of the CheckState enumeration.

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

using namespace System;
using namespace System::Drawing;
using namespace System::Collections;
using namespace System::ComponentModel;
using namespace System::Windows::Forms;
using namespace System::Data;
using namespace System::IO;

public ref class Form1: public System::Windows::Forms::Form
{
private:
   System::Windows::Forms::CheckedListBox^ checkedListBox1;
   System::Windows::Forms::TextBox^ textBox1;
   System::Windows::Forms::Button^ button1;
   System::Windows::Forms::Button^ button2;
   System::Windows::Forms::ListBox^ listBox1;
   System::Windows::Forms::Button^ button3;
   System::ComponentModel::Container^ components;

public:
   Form1()
   {
      InitializeComponent();
      
      // Sets up the initial objects in the CheckedListBox.
      array<String^>^myFruit = {"Apples","Oranges","Tomato"};
      checkedListBox1->Items->AddRange( myFruit );
      
      // Changes the selection mode from double-click to single click.
      checkedListBox1->CheckOnClick = true;
   }

public:
   ~Form1()
   {
      if ( components != nullptr )
      {
         delete components;
      }
   }

private:
   void InitializeComponent()
   {
      this->components = gcnew System::ComponentModel::Container;
      this->textBox1 = gcnew System::Windows::Forms::TextBox;
      this->checkedListBox1 = gcnew System::Windows::Forms::CheckedListBox;
      this->listBox1 = gcnew System::Windows::Forms::ListBox;
      this->button1 = gcnew System::Windows::Forms::Button;
      this->button2 = gcnew System::Windows::Forms::Button;
      this->button3 = gcnew System::Windows::Forms::Button;
      this->textBox1->Location = System::Drawing::Point( 144, 64 );
      this->textBox1->Size = System::Drawing::Size( 128, 20 );
      this->textBox1->TabIndex = 1;
      this->textBox1->TextChanged += gcnew System::EventHandler( this, &Form1::textBox1_TextChanged );
      this->checkedListBox1->Location = System::Drawing::Point( 16, 64 );
      this->checkedListBox1->Size = System::Drawing::Size( 120, 184 );
      this->checkedListBox1->TabIndex = 0;
      this->checkedListBox1->ItemCheck += gcnew System::Windows::Forms::ItemCheckEventHandler( this, &Form1::checkedListBox1_ItemCheck );
      this->listBox1->Location = System::Drawing::Point( 408, 64 );
      this->listBox1->Size = System::Drawing::Size( 128, 186 );
      this->listBox1->TabIndex = 3;
      this->button1->Enabled = false;
      this->button1->Location = System::Drawing::Point( 144, 104 );
      this->button1->Size = System::Drawing::Size( 104, 32 );
      this->button1->TabIndex = 2;
      this->button1->Text = "Add Fruit";
      this->button1->Click += gcnew System::EventHandler( this, &Form1::button1_Click );
      this->button2->Enabled = false;
      this->button2->Location = System::Drawing::Point( 288, 64 );
      this->button2->Size = System::Drawing::Size( 104, 32 );
      this->button2->TabIndex = 2;
      this->button2->Text = "Show Order";
      this->button2->Click += gcnew System::EventHandler( this, &Form1::button2_Click );
      this->button3->Enabled = false;
      this->button3->Location = System::Drawing::Point( 288, 104 );
      this->button3->Size = System::Drawing::Size( 104, 32 );
      this->button3->TabIndex = 2;
      this->button3->Text = "Save Order";
      this->button3->Click += gcnew System::EventHandler( this, &Form1::button3_Click );
      this->ClientSize = System::Drawing::Size( 563, 273 );
      array<System::Windows::Forms::Control^>^temp0 = {this->listBox1,this->button3,this->button2,this->button1,this->textBox1,this->checkedListBox1};
      this->Controls->AddRange( temp0 );
      this->Text = "Fruit Order";
   }

   // Adds the string if the text box has data in it.
   void button1_Click( Object^ /*sender*/, System::EventArgs^ /*e*/ )
   {
      if (  !textBox1->Text->Equals( "" ) )
      {
         if ( checkedListBox1->CheckedItems->Contains( textBox1->Text ) == false )
                  checkedListBox1->Items->Add( textBox1->Text, CheckState::Checked );
         textBox1->Text = "";
      }
   }

   // Activates or deactivates the Add button.
   void textBox1_TextChanged( Object^ /*sender*/, System::EventArgs^ /*e*/ )
   {
      if ( textBox1->Text->Equals( "" ) )
      {
         button1->Enabled = false;
      }
      else
      {
         button1->Enabled = true;
      }
   }

   // Moves the checked items from the CheckedListBox to the listBox.
   void button2_Click( Object^ /*sender*/, System::EventArgs^ /*e*/ )
   {
      listBox1->Items->Clear();
      button3->Enabled = false;
      for ( int i = 0; i < checkedListBox1->CheckedItems->Count; i++ )
      {
         listBox1->Items->Add( checkedListBox1->CheckedItems[ i ] );

      }
      if ( listBox1->Items->Count > 0 )
            button3->Enabled = true;
   }

   // Activates the move button if there are checked items.
   void checkedListBox1_ItemCheck( Object^ /*sender*/, ItemCheckEventArgs^ e )
   {
      if ( e->NewValue == CheckState::Unchecked )
      {
         if ( checkedListBox1->CheckedItems->Count == 1 )
         {
            button2->Enabled = false;
         }
      }
      else
      {
         button2->Enabled = true;
      }
   }

   // Saves the items to a file.
   void button3_Click( Object^ /*sender*/, System::EventArgs^ /*e*/ )
   {
      // Insert code to save a file.
      listBox1->Items->Clear();
      IEnumerator^ myEnumerator;
      myEnumerator = checkedListBox1->CheckedIndices->GetEnumerator();
      int y;
      while ( myEnumerator->MoveNext() != false )
      {
         y = safe_cast<Int32>(myEnumerator->Current);
         checkedListBox1->SetItemChecked( y, false );
      }

      button3->Enabled = false;
   }
};

[STAThread]
int main()
{
   Application::Run( gcnew Form1 );
}
namespace WindowsApplication1
{
   using System;
   using System.Drawing;
   using System.Collections;
   using System.ComponentModel;
   using System.Windows.Forms;
   using System.Data;
   using System.IO ;

   public class Form1 : System.Windows.Forms.Form
   {
      private System.Windows.Forms.CheckedListBox checkedListBox1;
      private System.Windows.Forms.TextBox textBox1;
      private System.Windows.Forms.Button button1;
      private System.Windows.Forms.Button button2;
      private System.Windows.Forms.ListBox listBox1;
      private System.Windows.Forms.Button button3;
        private System.ComponentModel.Container components;
      
      public Form1()
      {
            InitializeComponent();

         // Sets up the initial objects in the CheckedListBox.
            string[] myFruit = {"Apples", "Oranges","Tomato"};
         checkedListBox1.Items.AddRange(myFruit);

            // Changes the selection mode from double-click to single click.
         checkedListBox1.CheckOnClick = true;
      }

      protected override void Dispose( bool disposing )
	  {
		if( disposing )
		{
			if (components != null) 
			{
			  components.Dispose();
			}
		}
		base.Dispose( disposing );
	  }

      private void InitializeComponent()
      {
         this.components = new System.ComponentModel.Container();
         this.textBox1 = new System.Windows.Forms.TextBox();
         this.checkedListBox1 = new System.Windows.Forms.CheckedListBox();
         this.listBox1 = new System.Windows.Forms.ListBox();
         this.button1 = new System.Windows.Forms.Button();
         this.button2 = new System.Windows.Forms.Button();
         this.button3 = new System.Windows.Forms.Button();
         this.textBox1.Location = new System.Drawing.Point(144, 64);
         this.textBox1.Size = new System.Drawing.Size(128, 20);
         this.textBox1.TabIndex = 1;
         this.textBox1.TextChanged += new System.EventHandler(this.textBox1_TextChanged);
         this.checkedListBox1.Location = new System.Drawing.Point(16, 64);
         this.checkedListBox1.Size = new System.Drawing.Size(120, 184);
         this.checkedListBox1.TabIndex = 0;
         this.checkedListBox1.ItemCheck += new System.Windows.Forms.ItemCheckEventHandler(this.checkedListBox1_ItemCheck);
         this.listBox1.Location = new System.Drawing.Point(408, 64);
         this.listBox1.Size = new System.Drawing.Size(128, 186);
         this.listBox1.TabIndex = 3;
         this.button1.Enabled = false;
         this.button1.Location = new System.Drawing.Point(144, 104);
         this.button1.Size = new System.Drawing.Size(104, 32);
         this.button1.TabIndex = 2;
         this.button1.Text = "Add Fruit";
         this.button1.Click += new System.EventHandler(this.button1_Click);
         this.button2.Enabled = false;
         this.button2.Location = new System.Drawing.Point(288, 64);
         this.button2.Size = new System.Drawing.Size(104, 32);
         this.button2.TabIndex = 2;
         this.button2.Text = "Show Order";
         this.button2.Click += new System.EventHandler(this.button2_Click);
         this.button3.Enabled = false;
         this.button3.Location = new System.Drawing.Point(288, 104);
         this.button3.Size = new System.Drawing.Size(104, 32);
         this.button3.TabIndex = 2;
         this.button3.Text = "Save Order";
         this.button3.Click += new System.EventHandler(this.button3_Click);
         this.ClientSize = new System.Drawing.Size(563, 273);
         this.Controls.AddRange(new System.Windows.Forms.Control[] {this.listBox1,
                                                        this.button3,
                                                        this.button2,
                                                        this.button1,
                                                        this.textBox1,
                                                        this.checkedListBox1});
         this.Text = "Fruit Order";
      }

      [STAThread]
      public static void Main(string[] args) 
      {
         Application.Run(new Form1());
      }

      // Adds the string if the text box has data in it.
      private void button1_Click(object sender, System.EventArgs e)
      {
         if(textBox1.Text != "")
         {
            if(checkedListBox1.CheckedItems.Contains(textBox1.Text)== false)
               checkedListBox1.Items.Add(textBox1.Text,CheckState.Checked);
            textBox1.Text = "";
         }

      }
      // Activates or deactivates the Add button.
      private void textBox1_TextChanged(object sender, System.EventArgs e)
      {
         if (textBox1.Text == "")
         {
            button1.Enabled = false;
         }
         else
         {
            button1.Enabled = true;
         }
            
        }

      // Moves the checked items from the CheckedListBox to the listBox.
      private void button2_Click(object sender, System.EventArgs e)
      {
         listBox1.Items.Clear();
         button3.Enabled=false;
         for (int i=0; i< checkedListBox1.CheckedItems.Count;i++)
         {
            listBox1.Items.Add(checkedListBox1.CheckedItems[i]);
         }
         if (listBox1.Items.Count>0)
            button3.Enabled=true;
         
      }
        // Activates the move button if there are checked items.
      private void checkedListBox1_ItemCheck(object sender, ItemCheckEventArgs e)
      {
         if(e.NewValue==CheckState.Unchecked)
         {
            if(checkedListBox1.CheckedItems.Count==1)
            {
               button2.Enabled = false;
            }
         }
         else
         {
            button2.Enabled = true;
         }
      }

        // Saves the items to a file.
      private void button3_Click(object sender, System.EventArgs e)
      {   
         // Insert code to save a file.
         listBox1.Items.Clear();
         IEnumerator myEnumerator;
         myEnumerator = checkedListBox1.CheckedIndices.GetEnumerator();
         int y;
         while (myEnumerator.MoveNext() != false)
         {
            y =(int) myEnumerator.Current;
            checkedListBox1.SetItemChecked(y, false);
         }
         button3.Enabled = false ;
      }        
    }
}
   
Option Explicit
Option Strict

Imports System
Imports System.Drawing
Imports System.Collections
Imports System.ComponentModel
Imports System.Windows.Forms
Imports System.Data
Imports System.IO

Namespace WindowsApplication1
    Public Class Form1
        Inherits System.Windows.Forms.Form
        Private WithEvents checkedListBox1 As System.Windows.Forms.CheckedListBox
        Private WithEvents textBox1 As System.Windows.Forms.TextBox
        Private WithEvents button1 As System.Windows.Forms.Button
        Private WithEvents button2 As System.Windows.Forms.Button
        Private WithEvents listBox1 As System.Windows.Forms.ListBox
        Private WithEvents button3 As System.Windows.Forms.Button
        Private components As System.ComponentModel.Container
        
        
        Public Sub New()
            InitializeComponent()
            
            ' Sets up the initial objects in the CheckedListBox.
            Dim myFruit As String() =  {"Apples", "Oranges", "Tomato"}
            checkedListBox1.Items.AddRange(myFruit)
            
            ' Changes the selection mode from double-click to single click.
            checkedListBox1.CheckOnClick = True
        End Sub 'New
        
        
        Protected Overloads Overrides Sub Dispose(ByVal disposing As Boolean)
            If disposing Then
                If (components IsNot Nothing) Then
                    components.Dispose()
                End If
            End If
            MyBase.Dispose(disposing)
        End Sub
         
        Private Sub InitializeComponent()
            Me.components = New System.ComponentModel.Container()
            Me.textBox1 = New System.Windows.Forms.TextBox()
            Me.checkedListBox1 = New System.Windows.Forms.CheckedListBox()
            Me.listBox1 = New System.Windows.Forms.ListBox()
            Me.button1 = New System.Windows.Forms.Button()
            Me.button2 = New System.Windows.Forms.Button()
            Me.button3 = New System.Windows.Forms.Button()
            Me.textBox1.Location = New System.Drawing.Point(144, 64)
            Me.textBox1.Size = New System.Drawing.Size(128, 20)
            Me.textBox1.TabIndex = 1
            Me.checkedListBox1.Location = New System.Drawing.Point(16, 64)
            Me.checkedListBox1.Size = New System.Drawing.Size(120, 184)
            Me.checkedListBox1.TabIndex = 0
            Me.listBox1.Location = New System.Drawing.Point(408, 64)
            Me.listBox1.Size = New System.Drawing.Size(128, 186)
            Me.listBox1.TabIndex = 3
            Me.button1.Enabled = False
            Me.button1.Location = New System.Drawing.Point(144, 104)
            Me.button1.Size = New System.Drawing.Size(104, 32)
            Me.button1.TabIndex = 2
            Me.button1.Text = "Add Fruit"
            Me.button2.Enabled = False
            Me.button2.Location = New System.Drawing.Point(288, 64)
            Me.button2.Size = New System.Drawing.Size(104, 32)
            Me.button2.TabIndex = 2
            Me.button2.Text = "Show Order"
            Me.button3.Enabled = False
            Me.button3.Location = New System.Drawing.Point(288, 104)
            Me.button3.Size = New System.Drawing.Size(104, 32)
            Me.button3.TabIndex = 2
            Me.button3.Text = "Save Order"
            Me.ClientSize = New System.Drawing.Size(563, 273)
            Me.Controls.AddRange(New System.Windows.Forms.Control() {Me.listBox1, Me.button3, Me.button2, Me.button1, Me.textBox1, Me.checkedListBox1})
            Me.Text = "Fruit Order"
        End Sub 'InitializeComponent
        
        <STAThread()> _
        Public Shared Sub Main()
            Application.Run(New Form1())
        End Sub 'Main
        
        
        ' Adds the string if the text box has data in it.
        Private Sub button1_Click(sender As Object, _
                e As System.EventArgs) Handles button1.Click
            If textBox1.Text <> "" Then
                If checkedListBox1.CheckedItems.Contains(textBox1.Text) = False Then
                    checkedListBox1.Items.Add(textBox1.Text, CheckState.Checked)
                End If
                textBox1.Text = ""
            End If
        End Sub 'button1_Click
         
        ' Activates or deactivates the Add button.
        Private Sub textBox1_TextChanged(sender As Object, _
                e As System.EventArgs) Handles textBox1.TextChanged
            If textBox1.Text = "" Then
                button1.Enabled = False
            Else
                button1.Enabled = True
            End If
        End Sub 'textBox1_TextChanged
         
        
        ' Moves the checked items from the CheckedListBox to the listBox.
        Private Sub button2_Click(sender As Object, _
                e As System.EventArgs) Handles button2.Click
            listBox1.Items.Clear()
            button3.Enabled = False
            Dim i As Integer
            For i = 0 To checkedListBox1.CheckedItems.Count - 1
                listBox1.Items.Add(checkedListBox1.CheckedItems(i))
            Next i
            If listBox1.Items.Count > 0 Then
                button3.Enabled = True
            End If 
        End Sub 'button2_Click
        
        ' Activates the move button if there are checked items.
        Private Sub checkedListBox1_ItemCheck(sender As Object, _
                e As ItemCheckEventArgs) Handles checkedListBox1.ItemCheck
            If e.NewValue = CheckState.Unchecked Then
                If checkedListBox1.CheckedItems.Count = 1 Then
                    button2.Enabled = False
                End If
            Else
                button2.Enabled = True
            End If
        End Sub 'checkedListBox1_ItemCheck
        
        
        ' Saves the items to a file.
        Private Sub button3_Click(sender As Object, _
                e As System.EventArgs) Handles button3.Click
            ' Insert code to save a file.
            listBox1.Items.Clear()
            For Each index in checkedListBox1.CheckedIndices.Cast(Of Integer).ToArray()
                checkedListBox1.SetItemChecked(index, False)
            Next
            button3.Enabled = False
        End Sub 'button3_Click
    End Class 'Form1
End Namespace 'WindowsApplication1

Remarks

Multiple methods in CheckBox, CheckedListBox, and ItemCheckEventArgs use this enumeration.

Note

Use an indeterminately checked control when you do not want to set a default value.

Applies to