VB.NET panel addrange list of labels

Question

In my form, I have a panel. In a loop, I create many labels in this panel, but it's too slow.

So, it appears that create a list of labels in the loop and after add them in the panel should be more faster.

Here i my code :

Dim listLabels as new list(of label)
for a=0 to 100
 dim lbl as new label
 label.name="label" & a.Tostring
 listLabels.add(lbl)
next

myPanel.controls.addrange(listLabels)   

ERROR: Value of type 'List(of Label)' cannot be converted to 'Control()'

Can you help me please?

thks

Answer 1

Control.Controls returns a ControlCollection which AddRange accepts only a Control()(array of controls). So it's NOT a List<Control> which AddRange accepts IEnumerable<Control>. You could use ToArray, it creates an array from the list:

myPanel.Controls.AddRange(listLabels.ToArray()) 

Since you know the size already and you need an array, you could make it more efficient:

Dim labels(99) as Control  ' looks odd, but has place for 100 labels
For a As Integer = 0 To 99
    Dim lbl As New Label
    lbl.Name = "label" & a.Tostring
    labels(a) = lbl
Next
Label1.Controls.AddRange(labels)