ImageList Class

Definition

Namespace:

System.Windows.Forms

Assembly:

System.Windows.Forms.dll

Provides methods to manage a collection of Image objects. This class cannot be inherited.

public ref class ImageList sealed : System::ComponentModel::Component

[System.ComponentModel.TypeConverter(typeof(System.Windows.Forms.ImageListConverter))]
public sealed class ImageList : System.ComponentModel.Component

[<System.ComponentModel.TypeConverter(typeof(System.Windows.Forms.ImageListConverter))>]
type ImageList = class
    inherit Component

Public NotInheritable Class ImageList
Inherits Component

Inheritance

Object

MarshalByRefObject

Component

ImageList

Attributes

TypeConverterAttribute

Examples

The following code example shows how to select, remove, and display images.

namespace myImageRotator
#using <System.dll>
#using <System.Drawing.dll>
#using <System.Windows.Forms.dll>
{
    using namespace System;
    using namespace System::Drawing;
    using namespace System::ComponentModel;
    using namespace System::Windows::Forms;

    public ref class Form1 : public System::Windows::Forms::Form
    {
    private:
        System::ComponentModel::IContainer^ components;
    private:
        System::Windows::Forms::ListBox^ listBox1;
    private:
        System::Windows::Forms::Label^ label3;
    private:
        System::Windows::Forms::Button^ button1;
    private:
        System::Windows::Forms::Button^ button2;
    private:
        System::Windows::Forms::Button^ button3;
    private:
        System::Windows::Forms::Button^ button4;
    private:
        System::Windows::Forms::PictureBox^ pictureBox1;
    private:
        System::Windows::Forms::ImageList^ imageList1;
    private:
        System::Windows::Forms::OpenFileDialog^ openFileDialog1;
    protected:
        Graphics^ myGraphics;
    private:
        System::Windows::Forms::Panel^ panel1;
    private:
        System::Windows::Forms::Label^ label5;
    private:
        int currentImage;

    public:
        Form1()
        {
            InitializeComponent();
            imageList1 = gcnew ImageList () ;
            currentImage = 0;

            // The default image size is 16 x 16, which sets up a larger
            // image size. 
            imageList1->ImageSize = System::Drawing::Size(255,255);
            imageList1->TransparentColor = Color::White;

            // Assigns the graphics object to use in the draw options.
            myGraphics = Graphics::FromHwnd(panel1->Handle);
        }

    private:
        void InitializeComponent()
        {
            this->components = gcnew System::ComponentModel::Container();
            this->listBox1 = gcnew System::Windows::Forms::ListBox();
            this->label3 = gcnew System::Windows::Forms::Label();
            this->button1 = gcnew System::Windows::Forms::Button();
            this->button2 = gcnew System::Windows::Forms::Button();
            this->button3 = gcnew System::Windows::Forms::Button();
            this->button4 = gcnew System::Windows::Forms::Button();
            this->pictureBox1 = gcnew System::Windows::Forms::PictureBox();
            this->imageList1 = gcnew System::Windows::Forms::ImageList(this->components);
            this->openFileDialog1 = gcnew System::Windows::Forms::OpenFileDialog();
            this->panel1 = gcnew System::Windows::Forms::Panel();
            this->label5 = gcnew System::Windows::Forms::Label();
            this->SuspendLayout();

            this->listBox1->Location = System::Drawing::Point(16, 16);
            this->listBox1->Size = System::Drawing::Size(400, 95);
            this->listBox1->TabIndex = 0;

            this->label3->Location = System::Drawing::Point(24, 168);
            this->label3->Text = "label3";

            this->button1->Location = System::Drawing::Point(96, 128);
            this->button1->Size = System::Drawing::Size(104, 23);
            this->button1->Text = "Show Next Image";
            this->button1->Click += gcnew System::EventHandler(this,&Form1::button1_Click);

            this->button2->Location = System::Drawing::Point(208, 128);
            this->button2->Size = System::Drawing::Size(104, 23);
            this->button2->Text = "Remove Image";
            this->button2->Click += gcnew System::EventHandler(this,&Form1::button2_Click);

            this->button3->Location = System::Drawing::Point(320, 128);
            this->button3->Text = "Clear List";
            this->button3->Click += gcnew System::EventHandler(this,&Form1::button3_Click);

            this->button4->Location = System::Drawing::Point(16, 128);
            this->button4->Text = "Open Image";
            this->button4->Click += gcnew System::EventHandler(this,&Form1::button4_Click);

            this->pictureBox1->Location = System::Drawing::Point(328, 232);
            this->pictureBox1->Size = System::Drawing::Size(336, 192);

            this->imageList1->ImageSize = System::Drawing::Size(16, 16);
            this->imageList1->TransparentColor = System::Drawing::Color::Transparent;

            this->panel1->Location = System::Drawing::Point(8, 240);
            this->panel1->Size = System::Drawing::Size(296, 184);

            this->label5->Location = System::Drawing::Point(168, 168);
            this->label5->Size = System::Drawing::Size(312, 40);
            this->label5->Text = "label5";

            this->ClientSize = System::Drawing::Size(672, 461);
            this->Controls->Add(this->label5);
            this->Controls->Add(this->panel1);
            this->Controls->Add(this->pictureBox1);
            this->Controls->Add(this->button4);
            this->Controls->Add(this->button3);
            this->Controls->Add(this->button2);
            this->Controls->Add(this->button1);
            this->Controls->Add(this->label3);
            this->Controls->Add(this->listBox1);
            this->ResumeLayout(false);
        }

        // Display the image.
    private:
        void button1_Click (Object^ /*sender*/, System::EventArgs^ /*e*/)
        {
            if(imageList1->Images->Empty != true)
            {
                if(imageList1->Images->Count-1 > currentImage)
                {
                    currentImage++;
                }
                else
                {
                    currentImage=0;
                }
                panel1->Refresh();

                // Draw the image in the panel.
                imageList1->Draw(myGraphics,10,10,currentImage);

                // Show the image in the PictureBox.
                pictureBox1->Image = imageList1->Images[currentImage];
                label3->Text = "Current image is " + currentImage ;
                listBox1->SelectedIndex = currentImage;
                //				label5->Text = "Image is " + listBox1->Text ;
                label5->Text = String::Concat("Image is ",listBox1->Text);
            }
        }

        // Remove the image.
    private:
        void button2_Click (Object^ /*sender*/, System::EventArgs^ /*e*/)
        {
            imageList1->Images->RemoveAt(listBox1->SelectedIndex);
            listBox1->Items->Remove(listBox1->SelectedItem);
        }

        // Clear all images.
    private:
        void button3_Click (Object^ /*sender*/, System::EventArgs^ /*e*/)
        {
            imageList1->Images->Clear();
            listBox1->Items->Clear();
        }

        // Find an image.
    private:
        void button4_Click (Object^ /*sender*/, System::EventArgs^ /*e*/)
        {
            openFileDialog1->Multiselect = true ;
            if(openFileDialog1->ShowDialog() == System::Windows::Forms::DialogResult::OK)
            {
                if (openFileDialog1->FileNames != nullptr)
                {
                    for(int i =0 ; i < openFileDialog1->FileNames->Length ; i++ )
                    {
                        addImage(openFileDialog1->FileNames[i]);
                    }
                }
                else
                    addImage(openFileDialog1->FileName);
            }
           
        }

    private:
        void addImage(String^ imageToLoad)
        {
            if (imageToLoad != "")
            {
                imageList1->Images->Add(Image::FromFile(imageToLoad));
                listBox1->BeginUpdate();
                listBox1->Items->Add(imageToLoad);
                listBox1->EndUpdate();
            }
        }

    public:
        static void Main(array<String^>^ /*args*/) 
        {
            Application::Run(gcnew Form1());
        }
    };

}
[STAThreadAttribute] 
int main(){
    myImageRotator::Form1::Main(nullptr);
}

namespace myImageRotator
{
    using System;
    using System.Drawing;
    using System.ComponentModel;
    using System.Windows.Forms;
 
    public class Form1 : System.Windows.Forms.Form
    {
        private System.ComponentModel.IContainer components;
        private System.Windows.Forms.ListBox listBox1;
        private System.Windows.Forms.Label label3;
        private System.Windows.Forms.Button button1;
        private System.Windows.Forms.Button button2;
        private System.Windows.Forms.Button button3;
        private System.Windows.Forms.Button button4;
        private System.Windows.Forms.PictureBox pictureBox1;
        private System.Windows.Forms.ImageList imageList1;
        private System.Windows.Forms.OpenFileDialog openFileDialog1;
        protected Graphics myGraphics;
        private System.Windows.Forms.Panel panel1;
        private System.Windows.Forms.Label label5;
        private int currentImage = 0;
 
        public Form1()
        {
            InitializeComponent();
            imageList1 = new ImageList () ;

            // The default image size is 16 x 16, which sets up a larger
            // image size. 
            imageList1.ImageSize = new Size(255,255);
            imageList1.TransparentColor = Color.White;

            // Assigns the graphics object to use in the draw options.
            myGraphics = Graphics.FromHwnd(panel1.Handle);
        }
 
        private void InitializeComponent()
        {
            this.components = new System.ComponentModel.Container();
            this.listBox1 = new System.Windows.Forms.ListBox();
            this.label3 = new System.Windows.Forms.Label();
            this.button1 = new System.Windows.Forms.Button();
            this.button2 = new System.Windows.Forms.Button();
            this.button3 = new System.Windows.Forms.Button();
            this.button4 = new System.Windows.Forms.Button();
            this.pictureBox1 = new System.Windows.Forms.PictureBox();
            this.imageList1 = new System.Windows.Forms.ImageList(this.components);
            this.openFileDialog1 = new System.Windows.Forms.OpenFileDialog();
            this.panel1 = new System.Windows.Forms.Panel();
            this.label5 = new System.Windows.Forms.Label();
            this.SuspendLayout();

            this.listBox1.Location = new System.Drawing.Point(16, 16);
            this.listBox1.Size = new System.Drawing.Size(400, 95);
            this.listBox1.TabIndex = 0;

            this.label3.Location = new System.Drawing.Point(24, 168);
            this.label3.Text = "label3";

            this.button1.Location = new System.Drawing.Point(96, 128);
            this.button1.Size = new System.Drawing.Size(104, 23);
            this.button1.Text = "Show Next Image";
            this.button1.Click += new System.EventHandler(this.button1_Click);

            this.button2.Location = new System.Drawing.Point(208, 128);
            this.button2.Size = new System.Drawing.Size(104, 23);
            this.button2.Text = "Remove Image";
            this.button2.Click += new System.EventHandler(this.button2_Click);

            this.button3.Location = new System.Drawing.Point(320, 128);
            this.button3.Text = "Clear List";
            this.button3.Click += new System.EventHandler(this.button3_Click);

            this.button4.Location = new System.Drawing.Point(16, 128);
            this.button4.Text = "Open Image";
            this.button4.Click += new System.EventHandler(this.button4_Click);

            this.pictureBox1.Location = new System.Drawing.Point(328, 232);
            this.pictureBox1.Size = new System.Drawing.Size(336, 192);

            this.imageList1.ImageSize = new System.Drawing.Size(16, 16);
            this.imageList1.TransparentColor = System.Drawing.Color.Transparent;

            this.panel1.Location = new System.Drawing.Point(8, 240);
            this.panel1.Size = new System.Drawing.Size(296, 184);

            this.label5.Location = new System.Drawing.Point(168, 168);
            this.label5.Size = new System.Drawing.Size(312, 40);
            this.label5.Text = "label5";

            this.ClientSize = new System.Drawing.Size(672, 461);
            this.Controls.Add(this.label5);
            this.Controls.Add(this.panel1);
            this.Controls.Add(this.pictureBox1);
            this.Controls.Add(this.button4);
            this.Controls.Add(this.button3);
            this.Controls.Add(this.button2);
            this.Controls.Add(this.button1);
            this.Controls.Add(this.label3);
            this.Controls.Add(this.listBox1);
            this.ResumeLayout(false);
        }

        // Display the image.
        private void button1_Click (object sender, System.EventArgs e)
        {
            if(imageList1.Images.Empty != true)
            {
                if(imageList1.Images.Count-1 > currentImage)
                {
                    currentImage++;
                }
                else
                {
                    currentImage=0;
                }
                panel1.Refresh();
                
                // Draw the image in the panel.
                imageList1.Draw(myGraphics,10,10,currentImage);

                // Show the image in the PictureBox.
                pictureBox1.Image = imageList1.Images[currentImage];
                label3.Text = "Current image is " + currentImage ;
                listBox1.SelectedIndex = currentImage;
                label5.Text = "Image is " + listBox1.Text ;
            }
        }
 
        // Remove the image.
        private void button2_Click (object sender, System.EventArgs e)
        {
            imageList1.Images.RemoveAt(listBox1.SelectedIndex);
            listBox1.Items.Remove(listBox1.SelectedItem);
        }
 
        // Clear all images.
        private void button3_Click (object sender, System.EventArgs e)
        {
            imageList1.Images.Clear();
            listBox1.Items.Clear();
        }
 
        // Find an image.
        private void button4_Click (object sender, System.EventArgs e)
        {
            openFileDialog1.Multiselect = true ;
            if(openFileDialog1.ShowDialog() == DialogResult.OK)
            {
                if (openFileDialog1.FileNames != null)
                {
                    for(int i =0 ; i < openFileDialog1.FileNames.Length ; i++ )
                    {
                        addImage(openFileDialog1.FileNames[i]);
                    }
                }
                else
                {
                    addImage(openFileDialog1.FileName);
                }
            }
        }
 
        private void addImage(string imageToLoad)
        {
            if (imageToLoad != "")
            {
                imageList1.Images.Add(Image.FromFile(imageToLoad));
                listBox1.BeginUpdate();
                listBox1.Items.Add(imageToLoad);
                listBox1.EndUpdate();
            }
        }
        [STAThread]
        public static void Main(string[] args) 
        {
            Application.Run(new Form1());
        }
    }
}

Imports System.Drawing
Imports System.ComponentModel
Imports System.Windows.Forms

Public Class Form1
    Inherits System.Windows.Forms.Form
    Private listBox1 As System.Windows.Forms.ListBox
    Private label3 As System.Windows.Forms.Label
    Private WithEvents button1 As System.Windows.Forms.Button
    Private WithEvents button2 As System.Windows.Forms.Button
    Private WithEvents button3 As System.Windows.Forms.Button
    Private WithEvents button4 As System.Windows.Forms.Button
    Private pictureBox1 As System.Windows.Forms.PictureBox
    Private imageList1 As System.Windows.Forms.ImageList
    Private openFileDialog1 As System.Windows.Forms.OpenFileDialog
    Protected myGraphics As Graphics
    Private panel1 As System.Windows.Forms.Panel
    Private label5 As System.Windows.Forms.Label
    Private currentImage As Integer = 0

    Public Sub New()
        imageList1 = New ImageList()

        InitializeComponent()
        ' The default image size is 16 x 16, which sets up a larger
        ' image size. 
        imageList1.ImageSize = New Size(255, 255)
        imageList1.TransparentColor = Color.White

        ' Assigns the graphics object to use in the draw options.
        myGraphics = Graphics.FromHwnd(panel1.Handle)

    End Sub

    Private Sub InitializeComponent()

        Me.listBox1 = New System.Windows.Forms.ListBox()
        Me.label3 = New System.Windows.Forms.Label()
        Me.button1 = New System.Windows.Forms.Button()
        Me.button2 = New System.Windows.Forms.Button()
        Me.button3 = New System.Windows.Forms.Button()
        Me.button4 = New System.Windows.Forms.Button()
        Me.pictureBox1 = New System.Windows.Forms.PictureBox()
        Me.openFileDialog1 = New System.Windows.Forms.OpenFileDialog()
        Me.panel1 = New System.Windows.Forms.Panel()
        Me.label5 = New System.Windows.Forms.Label()
        Me.SuspendLayout()

        Me.listBox1.Location = New System.Drawing.Point(16, 16)
        Me.listBox1.Size = New System.Drawing.Size(400, 95)
        Me.listBox1.TabIndex = 0

        Me.label3.Location = New System.Drawing.Point(24, 168)
        Me.label3.Text = "label3"

        Me.button1.Location = New System.Drawing.Point(96, 128)
        Me.button1.Size = New System.Drawing.Size(104, 23)
        Me.button1.Text = "Show Next Image"

        Me.button2.Location = New System.Drawing.Point(208, 128)
        Me.button2.Size = New System.Drawing.Size(104, 23)
        Me.button2.Text = "Remove Image"

        Me.button3.Location = New System.Drawing.Point(320, 128)
        Me.button3.Text = "Clear List"

        Me.button4.Location = New System.Drawing.Point(16, 128)
        Me.button4.Text = "Open Image"

        Me.pictureBox1.Location = New System.Drawing.Point(328, 232)
        Me.pictureBox1.Size = New System.Drawing.Size(336, 192)

        Me.imageList1.ImageSize = New System.Drawing.Size(16, 16)
        Me.imageList1.TransparentColor = System.Drawing.Color.Transparent

        Me.panel1.Location = New System.Drawing.Point(8, 240)
        Me.panel1.Size = New System.Drawing.Size(296, 184)

        Me.label5.Location = New System.Drawing.Point(168, 168)
        Me.label5.Size = New System.Drawing.Size(312, 40)
        Me.label5.Text = "label5"

        Me.ClientSize = New System.Drawing.Size(672, 461)
        Me.Controls.Add(label5)
        Me.Controls.Add(panel1)
        Me.Controls.Add(pictureBox1)
        Me.Controls.Add(button4)
        Me.Controls.Add(button3)
        Me.Controls.Add(button2)
        Me.Controls.Add(button1)
        Me.Controls.Add(label3)
        Me.Controls.Add(listBox1)
        Me.ResumeLayout(False)
    End Sub

    ' Display the image.
    Private Sub button1_Click(ByVal sender As Object, _
        ByVal e As System.EventArgs) Handles button1.Click

        If imageList1.Images.Empty <> True Then
            If imageList1.Images.Count - 1 > currentImage Then
                currentImage += 1
            Else
                currentImage = 0
            End If
            panel1.Refresh()

            ' Draw the image in the panel.
            imageList1.Draw(myGraphics, 10, 10, currentImage)

            ' Show the image in the PictureBox.
            pictureBox1.Image = imageList1.Images(currentImage)
            label3.Text = "Current image is " + currentImage.ToString
            listBox1.SelectedIndex = currentImage
            label5.Text = "Image is " + listBox1.Text
        End If
    End Sub

    ' Remove the image.
    Private Sub button2_Click(ByVal sender As Object, _
        ByVal e As System.EventArgs) Handles button2.Click

        imageList1.Images.RemoveAt(listBox1.SelectedIndex)
        listBox1.Items.Remove(listBox1.SelectedItem)
    End Sub

    ' Clear all images.
    Private Sub button3_Click(ByVal sender As Object, _
        ByVal e As System.EventArgs) Handles button3.Click
        imageList1.Images.Clear()
        listBox1.Items.Clear()
    End Sub

    ' Find an image.
    Private Sub button4_Click(ByVal sender As Object, _
        ByVal e As System.EventArgs) Handles button4.Click

        openFileDialog1.Multiselect = True
        If openFileDialog1.ShowDialog() = DialogResult.OK Then
            If (openFileDialog1.FileNames IsNot Nothing) Then
                Dim i As Integer
                For i = 0 To openFileDialog1.FileNames.Length - 1
                    addImage(openFileDialog1.FileNames(i))
                Next i
            Else
                addImage(openFileDialog1.FileName)
            End If
        End If
    End Sub

    Private Sub addImage(ByVal imageToLoad As String)
        If imageToLoad <> "" Then
            imageList1.Images.Add(Image.FromFile(imageToLoad))
            listBox1.BeginUpdate()
            listBox1.Items.Add(imageToLoad)
            listBox1.EndUpdate()
        End If
    End Sub

    <StaThread()> _
    Public Shared Sub Main(ByVal args() As String)
        Application.Run(New Form1())
    End Sub
End Class

Remarks

ImageList is typically used by other controls, such as ListView, TreeView, or ToolBar. You can add bitmaps or icons to the ImageList, and the other controls are able to use the images as they require.

ImageList uses a handle to manage the list of images. The Handle is not created until certain operations, such as getting the Handle or calling Draw, are performed on the image list. Performing other operations, such as setting the ColorDepth or ImageSize, will cause the Handle to be recreated. Therefore, you should perform these operations before you add images to the ImageList. In addition, when you work with forms that will be localized, you should always add an ImageList and images when the Language property of a form is set to Default. Changing the form's language before you add images will corrupt the application resource files.

Constructors

ImageList()	Initializes a new instance of the ImageList class with default values for ColorDepth, ImageSize, and TransparentColor.
ImageList(IContainer)	Initializes a new instance of the ImageList class, associating it with a container.

Properties

CanRaiseEvents	Gets a value indicating whether the component can raise an event. (Inherited from Component)
ColorDepth	Gets or sets the color depth of the image list.
Container	Gets the IContainer that contains the Component. (Inherited from Component)
DesignMode	Gets a value that indicates whether the Component is currently in design mode. (Inherited from Component)
Events	Gets the list of event handlers that are attached to this Component. (Inherited from Component)
Handle	Gets the handle of the image list object.
HandleCreated	Gets a value indicating whether the underlying Win32 handle has been created.
Images	Gets the ImageList.ImageCollection for this image list.
ImageSize	Gets or sets the size of the images in the image list.
ImageStream	Gets or sets the ImageListStreamer associated with this image list.
Site	Gets or sets the ISite of the Component. (Inherited from Component)
Tag	Gets or sets an object that contains additional data about the ImageList.
TransparentColor	Gets or sets the color to treat as transparent.

Methods

CreateObjRef(Type)	Creates an object that contains all the relevant information required to generate a proxy used to communicate with a remote object. (Inherited from MarshalByRefObject)
Dispose()	Releases all resources used by the Component. (Inherited from Component)
Dispose(Boolean)	Releases the unmanaged resources used by the Component and optionally releases the managed resources. (Inherited from Component)
Draw(Graphics, Int32, Int32, Int32, Int32, Int32)	Draws the image indicated by the given index on the specified Graphics using the specified location and size.
Draw(Graphics, Int32, Int32, Int32)	Draws the image indicated by the given index on the specified Graphics at the specified location.
Draw(Graphics, Point, Int32)	Draws the image indicated by the specified index on the specified Graphics at the given location.
Equals(Object)	Determines whether the specified object is equal to the current object. (Inherited from Object)
GetHashCode()	Serves as the default hash function. (Inherited from Object)
GetLifetimeService()	Retrieves the current lifetime service object that controls the lifetime policy for this instance. (Inherited from MarshalByRefObject)
GetService(Type)	Returns an object that represents a service provided by the Component or by its Container. (Inherited from Component)
GetType()	Gets the Type of the current instance. (Inherited from Object)
InitializeLifetimeService()	Obtains a lifetime service object to control the lifetime policy for this instance. (Inherited from MarshalByRefObject)
MemberwiseClone()	Creates a shallow copy of the current Object. (Inherited from Object)
MemberwiseClone(Boolean)	Creates a shallow copy of the current MarshalByRefObject object. (Inherited from MarshalByRefObject)
ToString()	Returns a string that represents the current ImageList.

Events

Disposed	Occurs when the component is disposed by a call to the Dispose() method. (Inherited from Component)
RecreateHandle	Occurs when the Handle is recreated.

See also

• Bitmap
• Icon
• Metafile