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ImageList Class

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

Namespace:  System.Windows.Forms
Assembly:  System.Windows.Forms (in System.Windows.Forms.dll)

'Declaration
Public NotInheritable Class ImageList _
	Inherits Component

The ImageList type exposes the following members.

  NameDescription
Public methodImageListInitializes a new instance of the ImageList class with default values for ColorDepth, ImageSize, and TransparentColor.
Public methodImageList(IContainer)Initializes a new instance of the ImageList class, associating it with a container.
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  NameDescription
Public propertyColorDepthGets the color depth of the image list.
Public propertyContainerGets the IContainer that contains the Component. (Inherited from Component.)
Public propertyHandleGets the handle of the image list object.
Public propertyHandleCreatedGets a value indicating whether the underlying Win32 handle has been created.
Public propertyImagesGets the ImageList.ImageCollection for this image list.
Public propertyImageSizeGets or sets the size of the images in the image list.
Public propertyImageStreamGets the ImageListStreamer associated with this image list.
Public propertySiteGets or sets the ISite of the Component. (Inherited from Component.)
Public propertyTagGets or sets an object that contains additional data about the ImageList.
Public propertyTransparentColorGets or sets the color to treat as transparent.
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  NameDescription
Public methodCreateObjRefCreates an object that contains all the relevant information required to generate a proxy used to communicate with a remote object. (Inherited from MarshalByRefObject.)
Public methodDisposeReleases all resources used by the Component. (Inherited from Component.)
Public methodDraw(Graphics, Point, Int32)Draws the image indicated by the specified index on the specified Graphics at the given location.
Public methodDraw(Graphics, Int32, Int32, Int32)Draws the image indicated by the given index on the specified Graphics at the specified location.
Public methodDraw(Graphics, Int32, Int32, Int32, Int32, Int32)Draws the image indicated by the given index on the specified Graphics using the specified location and size.
Public methodEquals(Object)Determines whether the specified object is equal to the current object. (Inherited from Object.)
Public methodGetHashCodeServes as the default hash function. (Inherited from Object.)
Public methodGetLifetimeServiceRetrieves the current lifetime service object that controls the lifetime policy for this instance. (Inherited from MarshalByRefObject.)
Public methodGetTypeGets the Type of the current instance. (Inherited from Object.)
Public methodInitializeLifetimeServiceObtains a lifetime service object to control the lifetime policy for this instance. (Inherited from MarshalByRefObject.)
Public methodToStringInfrastructure. Returns a string that represents the current ImageList. (Overrides Component.ToString.)
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  NameDescription
Public eventDisposedOccurs when the component is disposed by a call to the Dispose method. (Inherited from Component.)
Public eventRecreateHandleOccurs when the Handle is recreated.
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ImageList is typically used by other controls, such as the 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.

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

Imports System
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 'New 

    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

.NET Framework

Supported in: 4.5.2, 4.5.1, 4.5, 4, 3.5, 3.0, 2.0, 1.1, 1.0

.NET Framework Client Profile

Supported in: 4, 3.5 SP1

Windows 8.1, Windows Server 2012 R2, Windows 8, Windows Server 2012, Windows 7, Windows Vista SP2, Windows Server 2008 (Server Core Role not supported), Windows Server 2008 R2 (Server Core Role supported with SP1 or later; Itanium not supported)

The .NET Framework does not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.

Any public static (Shared in Visual Basic) members of this type are thread safe. Any instance members are not guaranteed to be thread safe.
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