Question

I have some images that i added to imageList Cotrol manually.
Now i need remove thart images from imageList depending on the key index and set as panel backgroud.

How should i do it

Answer 1

Images that you added in Image list are added to the ImageList.ImageCollection, so it is collection type then you can use most of the collection methods.

Use the Images property to add, remove and access the image to display in background of panel.
Add(key,image)
Remove()
RemoveAt()
RemoveByKey()

Check the example on the ImageList Class documentation to understand that how pragmatically use all of these methods.

Add Image:

imageList1.Images.Add("pic1", Image.FromFile("c:\\mypic.jpg"));

Remove Image from collection:

imageList1.Images.RemoveAt(listBox1.SelectedIndex);
imageList1.Images..RemoveByKey("pic1");

To access images, get image from the imagecollection

panel1.BackgroundImage = imageList1.Images[0];

or

panel1.BackgroundImage = imageList1.Images["pic1"];