Upravit

Sdílet prostřednictvím

ButtonBase.ImageIndex Property

  • Reference

Definition

Namespace:
System.Windows.Forms
Assembly:
System.Windows.Forms.dll

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

public:
 property int ImageIndex { int get(); void set(int value); };
[System.ComponentModel.TypeConverter(typeof(System.Windows.Forms.ImageIndexConverter))]
public int ImageIndex { get; set; }
[<System.ComponentModel.TypeConverter(typeof(System.Windows.Forms.ImageIndexConverter))>]
member this.ImageIndex : int with get, set
Public Property ImageIndex As Integer

Property Value

Int32

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

Attributes
TypeConverterAttribute

Exceptions

ArgumentOutOfRangeException

value is less than -1.

Examples

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.
      imageList1->Images->Add( Image::FromFile( "C:\\Graphics\\MyBitmap.bmp" ) );
      // Assign the imageList to the button control.
      button1->ImageList = imageList1;
      // Select the image from the ImageList (using the ImageIndex property).
      button1->ImageIndex = 0;
   }

private void AddMyImage()
 {
    // Assign an image to the ImageList.
    ImageList1.Images.Add(Image.FromFile("C:\\Graphics\\MyBitmap.bmp"));
    // Assign the ImageList to the button control.   
    button1.ImageList = ImageList1;
    // Select the image from the ImageList (using the ImageIndex property).    
    button1.ImageIndex = 0;
 }

Private Sub AddMyImage()
    ' Assign an image to the ImageList.
    ImageList1.Images.Add(Image.FromFile("C:\Graphics\MyBitmap.bmp"))
    ' Assign the ImageList to the button control.   
    button1.ImageList = ImageList1
    ' Select the image from the ImageList (using the ImageIndex property).    
    button1.ImageIndex = 0
End Sub

Remarks

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

ImageKey and ImageIndex are mutually exclusive, meaning if one is set, the other is set to an invalid value and ignored. If you set the ImageKey property, the ImageIndex property is automatically set to -1. Alternatively, if you set the ImageIndex property, the ImageKey is automatically set to an empty string ("").

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.

Applies to

See also