I am using the code below to add multiple LineShape controls to a Windows Form. Note the globally declared mLineShapes() and mShapeContainter() arrays (at bottom of code) which store each new LineShape object once it's created.
At present, I have been unsuccessful at removing a given LineShape control from the form (even if I know its array index), and also cannot removing an array element without causing a Nothing for the removed element. Obviously, once I remove the element from these arrays, it requires that all the remaining elements with greater indices are copied to lower values to fill in the Nothing voided element. Given these circumstances, can lists be used instead of the mLineShapes() and mShapeContainer() arrays?
enter code here' create new ShapeContainer
Dim sSCTemp As New ShapeContainer
' add ShapeContainer to Form
sSCTemp.Parent = Me
' create new LineShape
Dim sLSTemp As New LineShape
sLSTemp.BorderColor = Color.Black
sLSTemp.BorderWidth = 2
sLSTemp.Cursor = Cursors.Cross
' add LineShape to ShapeContainer
sLSTemp.Parent = sSCTemp
' set starting and ending coordinates for the line
sLSTemp.StartPoint = New System.Drawing.Point(siSCCount * 20, 60 + siSCCount * 60)
sLSTemp.EndPoint = New System.Drawing.Point(100 + siSCCount * 20, 110 + siSCCount * 60)
' set new LineShape to top of z-order
sLSTemp.BringToFront()
sSCTemp.BringToFront()
' connect ContextMenuStrip to LineShape
sLSTemp.ContextMenuStrip = mLsCtm1
' add new LineShape to arrays
ReDim Preserve mLineShapes(siSCCount)
ReDim Preserve mShapeContainer(siSCCount)
mLineShapes(siSCCount) = sLSTemp
mLineShapes(siSCCount).Name = "LineShape" & siSCCount
mShapeContainer(siSCCount) = sSCTemp
mShapeContainer(siSCCount).Name = "ShapeContainer" & siSCCount
In addition to the above, the endpoints of each LineShape are selected from the arrays so that they can be moved. An example is below:
Dim siSCId As Integer
Dim myShapeContainer As ShapeContainer
myShapeContainer = CType(sender, ShapeContainer)
Dim myLineShape As LineShape
' get index of the actual ShapeContainer in ShapeContainer array
siSCId = Array.IndexOf(mShapeContainer, sender)
If siSCId > -1 Then
myLineShape = mLineShapes(siSCId)
If MouseIsNearBy(myLineShape.EndPoint) Then
myLineShape.BorderColor = Color.Red
NearLineEndPoint = True
End If
If MouseIsNearBy(myLineShape.EndPoint) = False Then
myLineShape.BorderColor = Color.Black
NearLineEndPoint = False
End If
If (dragStartPoint) Then
myLineShape.StartPoint = New Point(oldStartPoint.X + e.X - oldMouseX, oldStartPoint.Y + e.Y - oldMouseY)
End If
End If
Therefore, If I simply add a new LineShape to the form controls without using the mLineShapes() ans mShapeControl() arrays, how can I modify the above code (which finds the LineShape in the storage arrays) so that the line can be modified? I think that if I click on a LineShape, I can get its name using .sourcecontrol or .parent?
UPDATE 5/9/2019
After right clicking on a control on Form1 and selecting the "Link" command from a ContextMenuStrip, the following method (ctmsconnect) is fired to draw a new LineShape control that the user then drags and drops on to the next control in the workflow. Question is, is the list of LineShapes ("Lines") not needed?
(in Form1 class declarations):
Dim SC As New ShapeContainer
Dim Lines As New List(Of LineShape)
Private Sub ctmsconnect_Click(sender As System.Object, e As System.EventArgs) Handles ctmsconnect.Click
mLineWidth = 1
Dim myItem As ToolStripMenuItem = CType(sender, ToolStripMenuItem)
Dim cms As ContextMenuStrip = CType(myItem.Owner, ContextMenuStrip)
Dim x As Integer = cms.SourceControl.Right - 2
Dim y As Integer = cms.SourceControl.Top + (cms.SourceControl.Height / 2 - 12)
Dim LS As New LineShape
NumLineShapes += 1
LS.Name = "LineShape" & NumLineShapes
LS.BorderColor = Color.Black
LS.BorderWidth = 2
'Set starting and ending coordinates for the line
LS.StartPoint = New Point(x, y)
LS.EndPoint = New Point(x + 80, y - 5)
'Set new LineShape to top of z-order
LS.BringToFront()
Dim nxgContextMenuStrip As New ContextMenuStrip
LS.ContextMenuStrip = nxgContextMenuStrip
LS.Tag = "LineShape" & NumLineShapes & "_Delete"
'Attach an event handler for the ContextMenuStrip control's Opening event.
AddHandler nxgContextMenuStrip.Opening, AddressOf cms_Opening
numconnectedlineendpoints += 1
Dim myValues As New List(Of String)
myValues.Add(cms.SourceControl.Name)
DropLineOriginalObjectName = cms.SourceControl.Name
OrigDropControl = cms.SourceControl
myValues.Add(LS.Name)
myValues.Add("linestart")
dicGUIControls.Add(numconnectedlineendpoints, myValues)
Lines.Add(LS)
SC.Shapes.Add(LS)
Me.Refresh()
End Sub
You shouldn't need the arrays, just use the controls collection. Instead of setting the parent of the controls, you should probably add them to the collection:
'sSCTemp.Parent = Me
Me.Controls.Add(sSCTemp)
To remove them, you can reference them by the name property:
If Me.Controls.ContainsKey("ShapeContainer1") Then
Me.Controls.RemoveByKey("ShapeContainer1")
End If
The shape controls inside the ShapeContainer have to be accessed through the Shape collection:
If Me.Controls.ContainsKey("ShapeContainer1") Then
Dim sc As ShapeContainer = DirectCast(Me.Controls("ShapeContainer1"), ShapeContainer)
If sc.Shapes.ContainsKey("LineShape2") Then
sc.Shapes.RemoveAt(sc.Shapes.IndexOfKey("LineShape2"))
End If
End If
Example of reading the StartPoint and EndPoint properties:
Dim sb As New StringBuilder
For Each ls As LineShape In Me.ShapeContainer1.Shapes
sb.AppendLine(ls.StartPoint.ToString & " - " & ls.EndPoint.ToString)
Next
MessageBox.Show(sb.ToString)
Note: ShapeContainer Class makes a special note:
Be careful that you do not create more than one ShapeContainer for each form or container; doing this may introduce unexpected behavior. If you add a design-time line or shape control to a form or container after you write code to create one programmatically, you should modify that code to use the ShapeContainer created by the designer.