Draw a rectangle with the mouse, but not when OpenfileDialog is busy - vb.net

Question

I have a Form1 and a PictureBox. I have also subscribed to the MouseDown, MouseMove and MouseUp events in order to be able to draw a rectangle on the PictureBox with the mouse. In itself, it works fine. Now I am using an OpenFileDialog. If I select the file in the window and click on 'OK', the dialog disappears, but – and this is my problem – a rectangle is drawn immediately because I moved the mouse. I don't want that to happen at the moment. I've already tried to use a Boolean variable to lock the MouseMove procedure, but unfortunately that didn't work.OpenFileDialog Here you can see the accidentally created rectangle
Imports Microsoft.WindowsAPICodePack.Dialogs
Public NotInheritable Class Form1
Private Mausstartpunkt As Point ' Mouse start point
Private Mausendpunkt As Point ' Mouse end point
Public Shared Property Picture1 As Bitmap 'dann bleibt es im Anwendungs-Scope, wenn die Klasse verfällt.
Private Pfad_Bild As String = ""
Private Pfad_speichern As String = ""
Private It_is_allowed_to_draw As Boolean
Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load
End Sub
Private Sub PictureBox1_Paint(sender As Object, e As PaintEventArgs) Handles PictureBox1.Paint
If PictureBox1.Image IsNot Nothing AndAlso It_is_allowed_to_draw AndAlso Not String.IsNullOrEmpty(Pfad_Bild) Then
Dim rect As Rectangle = PointsToRectangle(Mausstartpunkt, Mausendpunkt)
AllesGrafische.Paint_the_Rectangle(e.Graphics, rect)
End If
End Sub
Private Sub PictureBox1_MouseDown(sender As Object, e As MouseEventArgs) Handles PictureBox1.MouseDown
If e.Button = MouseButtons.Left Then
Mausstartpunkt = System.Windows.Forms.Control.MousePosition
Mausstartpunkt = New Point(Mausstartpunkt.X - 8, Mausstartpunkt.Y - 31)
End If
If e.Button = MouseButtons.Right Then ' clears the rectangle
Mausstartpunkt = New Point(0, 0)
Mausendpunkt = New Point(0, 0)
PictureBox1.Invalidate()
End If
End Sub
Private Sub PictureBox1_MouseMove(sender As Object, e As MouseEventArgs) Handles PictureBox1.MouseMove
If e.Button = MouseButtons.Left Then
Mausendpunkt = System.Windows.Forms.Control.MousePosition
Mausendpunkt = New Point(Mausendpunkt.X - 8, Mausendpunkt.Y - 31)
PictureBox1.Invalidate()
End If
End Sub
Private Sub PictureBox1_MouseUp(sender As Object, e As MouseEventArgs) Handles PictureBox1.MouseUp
If e.Button = MouseButtons.Left Then
Mausendpunkt = System.Windows.Forms.Control.MousePosition
Mausendpunkt = New Point(Mausendpunkt.X - 8, Mausendpunkt.Y - 31)
PictureBox1.Invalidate()
End If
End Sub
Public Shared Function PointsToRectangle(ByVal p1 As Point, ByVal p2 As Point) As Rectangle 'https://www.vb-paradise.de/index.php/Thread/20037-Rechteck-mit-Maus-zeichnen-Erledigt/?postID=124893#post124893
Dim r As New Rectangle With {
.Width = Math.Abs(p1.X - p2.X),
.Height = Math.Abs(p1.Y - p2.Y),
.X = Math.Min(p1.X, p2.X),
.Y = Math.Min(p1.Y, p2.Y)
}
Return r
End Function
Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
PictureBox1.Image = Nothing
Using OFD As New CommonOpenFileDialog
OFD.Title = "Datei zum Öffnen auswählen"
OFD.Filters.Add(New CommonFileDialogFilter("Bilder", ".jpg;.jpeg;.bmp"))
OFD.Filters.Add(New CommonFileDialogFilter("PNG", ".png"))
OFD.InitialDirectory = Environment.GetFolderPath(Environment.SpecialFolder.Desktop)
If OFD.ShowDialog() = CommonFileDialogResult.Ok Then
Pfad_Bild = OFD.FileName
Pfad_speichern = Pfad_Bild.Substring(0, Pfad_Bild.LastIndexOf("\", StringComparison.Ordinal) + 1) ' for example "C:\Users\myName\Pictures\", or "C:\Users\myName\Desktop\"
Else
Return
End If
End Using
Picture1 = New Bitmap(Pfad_Bild)
PictureBox1.Image = Picture1
It_is_allowed_to_draw = True
End Sub
And this is the code for my graphics class
Imports System.Drawing.Drawing2D
Public NotInheritable Class AllesGrafische
Public Shared Sub Paint_the_Rectangle(ByVal g As Graphics, ByVal recta As Rectangle)
If g IsNot Nothing Then
g.SmoothingMode = SmoothingMode.AntiAlias
g.CompositingQuality = CompositingQuality.HighQuality
g.PixelOffsetMode = PixelOffsetMode.HighQuality
g.InterpolationMode = InterpolationMode.HighQualityBilinear
Using Pen_Hellblau As Pen = New Pen(Color.FromArgb(0, 200, 255), 1.0F)
g.DrawRectangle(Pen_Hellblau, recta)
End Using
End If
End Sub
End Class

Answer 1

Set a Boolean field to True on the MouseDown event and then only act on the MouseUp if that flag is set.