working with controls(linklabels, treeview) in winforms

I have a Panel and two LinkLabels added on the panel and a treeview.

now in the panel_Paint event i want that the linklabel colors become white and background color of treeview turns black. how do i do this?

the below code works only when there is no tr开发者_如何学Cee view in the panel but when i add a treeview also in the panel then it says :

Unable to cast object of type 'System.Windows.Forms.TreeView' to type 'System.Windows.Forms.LinkLabel'.

foreach (LinkLabel link in panel1.Controls)
{         
    link.LinkColor = Color.White; 
}

Your panel contains all the controls - one of them is a TreeView which cannot be cast into a LinkLabel. In your loop you need to check the type of the control like this:

foreach (Control control in panel1.Controls)
{
   if (control is LinkLabel)
   {
       ... set link color
   }
   else if (control is TreeView)
   {
       ... set background
   }
}

Alternatively if you only have one LinkLabel and one TreeView you would not need a loop - just access them by name like you did with panel1

Try this:

foreach (Control ctrl in panel1.Controls)
{
     LinkLabel link = ctrl as LinkLabel;
     if(link != null)
        link.LinkColor = Color.White; 
}

Your getting the error because your trying to cast all controls in panel1 to a LinkLabel. You need to try something like this

foreach (Control control in panel1.Controls)
{
       if (control.GetType() == typeof(LinkLabel))
       {
            LinkLabel link = (LinkLabel)control;
            link.LinkColor = Color.White; 
       } 
}

Hope this helps.

Edit: I knew there was a method but wasn't sure 100% of the name or syntax. See below an improved answer.

foreach (LinkLabel link in panel1.Controls.OfType<LinkLabel>())
{
    link.LinkColor = Color.White;
}

Hope this is better for you.