VB.net nearest control - vb.net

Question

Is there an easy way to get the nearest control to a control of choice?
I have a picture box and some other moving controls. I want to delete the nearest control to my picture box.
So I have to get the position of all controls and delete that with the Location nearest to the Location of my picture box. I'm not sure about how to do that the best way.

Answer 1

If "closest" in your case indeed means "with the Location nearest to the Location of my picture box", then the easiest would be:
Me.Controls.Remove((From c In Me.Controls.Cast(Of Control)() Order By c.Location.Distance(PictureBox1.Location) Select c).Skip(1).Take(1)(0))
, where Distance is defined in a module like this:
<System.Runtime.CompilerServices.Extension()> _
Public Function Distance(ByVal p1 As Point, ByVal p2 As Point) As Integer
Return (p1.X - p2.X) * (p1.X - p2.X) + (p1.Y - p2.Y) * (p1.Y - p2.Y)
End Function

Answer 2

Here's an entire sample form that calculates "closest" by checking if the supplied control is in 1 of 8 regions relative to the base control. Half of the code is setup trying to mimic the scenario you described. The MainButton_Click and below is the meat of the work.
Option Explicit On
Option Strict On
Public Class Form1
Private MainPB As PictureBox
Private OtherPB As List(Of PictureBox)
Private WithEvents MainButton As Button
Private Rnd As New Random()
Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
'Setup the form with sample data
Me.FormBorderStyle = Windows.Forms.FormBorderStyle.None
Me.MainButton = New Button()
Me.MainButton.Text = "Update"
Me.MainButton.Left = 1
Me.MainButton.Top = 20
Me.Controls.Add(Me.MainButton)
Me.Width = 1000
Me.Height = 1000
MainPB = New PictureBox()
MainPB.BackColor = Color.Red
MainPB.Width = 100
MainPB.Height = 100
MainPB.Left = (Me.Width \ 2) - (MainPB.Width \ 2)
MainPB.Top = (Me.Height \ 2) - (MainPB.Height \ 2)
Me.Controls.Add(MainPB)
Me.OtherPB = New List(Of PictureBox)
For I = 0 To 50
Me.OtherPB.Add(New PictureBox())
With Me.OtherPB(I)
.BackColor = Color.Transparent
.BorderStyle = BorderStyle.FixedSingle
.Width = 50
.Height = 50
End With
SetRandomPbLocation(Me.OtherPB(I))
Me.Controls.Add(Me.OtherPB(I))
Next
End Sub
Private Sub SetRandomPbLocation(ByVal pb As PictureBox)
'Just sets a random location for the picture boxes and ensures that it doesn't overlap with the center PB
Do While True
pb.Left = Rnd.Next(1, Me.Width - pb.Width)
pb.Top = Rnd.Next(1, Me.Height - pb.Height)
If (pb.Right < Me.MainPB.Left OrElse pb.Left > Me.MainPB.Right) AndAlso (pb.Top > Me.MainPB.Bottom OrElse pb.Bottom < Me.MainPB.Top) Then
Exit Do
End If
Loop
End Sub
Private Sub MainButton_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles MainButton.Click
'Randomizes the location of the picture boxes
For Each PB In Me.OtherPB
SetRandomPbLocation(PB)
Next
'Will hold the closest control after the loop
Dim ClosestPB As Control = Nothing
Dim ClosestD, TempD As Double
For Each PB In Me.OtherPB
'Reset the control's background color
PB.BackColor = Color.Transparent
'Calculate the distance
TempD = GetDistanceBetweenToControls(PB, Me.MainPB)
If ClosestPB Is Nothing Then 'If this is the first time through the loop then just use this control as the closest
ClosestPB = PB
ClosestD = TempD
ElseIf TempD < ClosestD Then 'Otherwise if this control is closer than the current closest
ClosestPB = PB
ClosestD = TempD
End If
Next
'Set the closest controls background color so that we can see it
ClosestPB.BackColor = Color.Blue
End Sub
Private Shared Function GetDistanceBetweenToControls(ByVal controlToCheck As Control, ByVal baseControl As Control) As Double
If controlToCheck.Bottom < baseControl.Top Then
If controlToCheck.Right < baseControl.Left Then 'Above and to the left
Return DistanceBetweenTwoPoints(New Point(controlToCheck.Right, controlToCheck.Bottom), baseControl.Location)
ElseIf controlToCheck.Left > baseControl.Right Then 'above and to the right
Return DistanceBetweenTwoPoints(New Point(controlToCheck.Left, controlToCheck.Bottom), New Point(baseControl.Right, baseControl.Top))
Else 'Above
Return baseControl.Top - baseControl.Bottom
End If
ElseIf controlToCheck.Top > baseControl.Bottom Then
If controlToCheck.Right < baseControl.Left Then 'Below and to the left
Return DistanceBetweenTwoPoints(New Point(controlToCheck.Right, controlToCheck.Top), New Point(baseControl.Left, baseControl.Bottom))
ElseIf controlToCheck.Left > baseControl.Right Then 'Below and to the right
Return DistanceBetweenTwoPoints(controlToCheck.Location, New Point(baseControl.Right, baseControl.Bottom))
Else 'Below
Return controlToCheck.Top - baseControl.Bottom
End If
Else
If controlToCheck.Right < baseControl.Left Then 'Left
Return baseControl.Left - controlToCheck.Right
ElseIf controlToCheck.Left > baseControl.Right Then 'Right
Return controlToCheck.Left - baseControl.Right
End If
End If
End Function
Private Shared Function DistanceBetweenTwoPoints(ByVal point1 As Point, ByVal point2 As Point) As Double
'Standard distance formula
Return Math.Sqrt((Math.Abs(point2.X - point1.X) ^ 2) + (Math.Abs(point2.Y - point1.Y) ^ 2))
End Function
End Class