D
Dr. Zharkov
Hello. A problem in the following.
In VB .NET 2003 I create the project and in file Form1.vb is written down
the following code:
Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As
System.EventArgs) Handles MyBase.Load
'Create the data:
CreateData() 'Error
End Sub
'Create the data:
Private Sub CreateData()
'Axes X, Y, Z:
MakeSegment(0, 0, 0, 0.5, 0, 0) ' X axis. 'Error
MakeSegment(0, 0, 0, 0, 0.5, 0) ' Y axis.
MakeSegment(0, 0, 0, 0, 0, 0.5) ' Z axis.
End Sub
Public Structure Segment
'Connect the points:
<VBFixedArray(4)> Dim fr_pt() As Single
<VBFixedArray(4)> Dim to_pt() As Single
'Connect the transformed points:
<VBFixedArray(4)> Dim fr_tr() As Single
<VBFixedArray(4)> Dim to_tr() As Single
Public Sub Initialize()
ReDim fr_pt(4)
ReDim to_pt(4)
ReDim fr_tr(4)
ReDim to_tr(4)
End Sub
End Structure
Public Structure Transformation
<VBFixedArray(4, 4)> Dim M(,) As Single
Public Sub Initialize()
ReDim M(4, 4)
End Sub
End Structure
Public NumSegments As Short
Public Segments() As Segment
'Create a segment:
Public Sub MakeSegment(ByVal x1 As Single, ByVal y1 As Single, ByVal z1
As Single, _
ByVal x2 As Single, ByVal y2 As Single, ByVal z2
As Single)
NumSegments = NumSegments + 1
ReDim Preserve Segments(NumSegments)
Segments(NumSegments).fr_pt(1) = x1 'Error
Segments(NumSegments).fr_pt(2) = y1
Segments(NumSegments).fr_pt(3) = z1
Segments(NumSegments).fr_pt(4) = 1
Segments(NumSegments).to_pt(1) = x2
Segments(NumSegments).to_pt(2) = y2
Segments(NumSegments).to_pt(3) = z2
Segments(NumSegments).to_pt(4) = 1
End Sub
Building the project (Build, Build Solution) is carried out without errors.
However at running there are errors in the specified lines and the message:
Object reference not set to an instance of an object.
Inform, please, how to correct errors?
Beforehand many thanks for answer. Best regards, Dr. V.A. Zharkov. Moscow,
Russia.
In VB .NET 2003 I create the project and in file Form1.vb is written down
the following code:
Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As
System.EventArgs) Handles MyBase.Load
'Create the data:
CreateData() 'Error
End Sub
'Create the data:
Private Sub CreateData()
'Axes X, Y, Z:
MakeSegment(0, 0, 0, 0.5, 0, 0) ' X axis. 'Error
MakeSegment(0, 0, 0, 0, 0.5, 0) ' Y axis.
MakeSegment(0, 0, 0, 0, 0, 0.5) ' Z axis.
End Sub
Public Structure Segment
'Connect the points:
<VBFixedArray(4)> Dim fr_pt() As Single
<VBFixedArray(4)> Dim to_pt() As Single
'Connect the transformed points:
<VBFixedArray(4)> Dim fr_tr() As Single
<VBFixedArray(4)> Dim to_tr() As Single
Public Sub Initialize()
ReDim fr_pt(4)
ReDim to_pt(4)
ReDim fr_tr(4)
ReDim to_tr(4)
End Sub
End Structure
Public Structure Transformation
<VBFixedArray(4, 4)> Dim M(,) As Single
Public Sub Initialize()
ReDim M(4, 4)
End Sub
End Structure
Public NumSegments As Short
Public Segments() As Segment
'Create a segment:
Public Sub MakeSegment(ByVal x1 As Single, ByVal y1 As Single, ByVal z1
As Single, _
ByVal x2 As Single, ByVal y2 As Single, ByVal z2
As Single)
NumSegments = NumSegments + 1
ReDim Preserve Segments(NumSegments)
Segments(NumSegments).fr_pt(1) = x1 'Error
Segments(NumSegments).fr_pt(2) = y1
Segments(NumSegments).fr_pt(3) = z1
Segments(NumSegments).fr_pt(4) = 1
Segments(NumSegments).to_pt(1) = x2
Segments(NumSegments).to_pt(2) = y2
Segments(NumSegments).to_pt(3) = z2
Segments(NumSegments).to_pt(4) = 1
End Sub
Building the project (Build, Build Solution) is carried out without errors.
However at running there are errors in the specified lines and the message:
Object reference not set to an instance of an object.
Inform, please, how to correct errors?
Beforehand many thanks for answer. Best regards, Dr. V.A. Zharkov. Moscow,
Russia.