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ButtonBase.ImageIndex Property

Gets or sets the image list index value of the image displayed on the button control.

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

public int ImageIndex { get; set; }

Property Value

Type: System.Int32
A zero-based index, which represents the image position in an ImageList. The default is -1.


The assigned value is less than the lower bounds of the ImageIndex.

When the ImageIndex or ImageList properties are set, the Image property is set to its default value, null.


If the ImageList property value is changed to null, the ImageIndex property returns its default value, -1. However, the assigned ImageIndex value is retained internally and used when another ImageList object is assigned to the ImageList property. If the new ImageList assigned to the ImageList property has an ImageList.ImageCollection.Count property value that is less than or equal to the value assigned to the ImageIndex property minus one (to account for the collection being a zero-based index), the ImageIndex property value is adjusted to one less than the Count property value. For example, consider a button control whose ImageList has three images and whose ImageIndex property is set to 2. If a new ImageList that has only two images is assigned to the button, the ImageIndex value changes to 1.

The following code example uses the derived class, Button and sets the ImageList and ImageIndex properties. This code requires that an ImageList has been created and a minimum of one Image has been assigned to it. This code also requires that you have a bitmap image named MyBitMap.bmp stored in the C:\Graphics directory.

private void AddMyImage()
    // Assign an image to the ImageList.
    // Assign the ImageList to the button control.   
    button1.ImageList = ImageList1;
    // Select the image from the ImageList (using the ImageIndex property).    
    button1.ImageIndex = 0;

.NET Framework

Supported in: 4, 3.5, 3.0, 2.0, 1.1, 1.0

.NET Framework Client Profile

Supported in: 4, 3.5 SP1

Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows XP SP2 x64 Edition, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2

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