How to Make Help File With VB.NET

strNode = xNode.SelectSingleNode("title").InnerText
tvHelp.Nodes(0).Nodes(2).Nodes.Add(strNode)
' add Property title to ComboBox
cmbHeading.Items.Add(strNode)
Next
' set Method nodes image
For i As Integer = 0 To tvHelp.Nodes(0).Nodes(2).Nodes.Count - 1
tvHelp.Nodes(0).Nodes(2).Nodes(i).ImageIndex = 2
tvHelp.Nodes(0).Nodes(2).Nodes(i).SelectedImageIndex = 2
Next

cmbHeading.SelectedIndex = 0
Catch ex As Exception
MessageBox.Show(ex.Message)
End Try
End Sub

How to read a help when clicking any item? The following procedure can do the job:

Private Sub DisplayHelp(ByVal strName As String)
Dim xNode As XmlElement
Dim strHelp As String

' if user click any title
xNode = XmlDoc.SelectSingleNode("//*[title='" + strName + "']")
strHelp = xNode.InnerText
txtHelp.Text = strHelp
End Sub

We need three events to display help when click tvHelp node, when click btnDisplay or when click any item of cmbHeading ComboBox:

Please read the code of tvHelp_AfterSelect (), btnDisplay_Click() andcmbHeading_MouseDoubleClick ()

If you don't like the code of frmHelp1 form and MyHelp1.xml file, you can use the following code of frmHelp2 form and MyHelp2.xml file.

Code for frmHelp2:

We shall read a nodes name from the MyHelp2.xml file to set it to tvHelp TreeView control, we do this by two procedures LoadHeading() and AddNextNodes():

Private Sub LoadHeading()
Dim XmlDoc As New XmlDocument
XmlDoc.Load(MyHelpFile)
' Add first node (the Root)
tvHelp.Nodes.Add(New TreeNode(XmlDoc.DocumentElement.Name))
Dim tNode As New TreeNode
tNode = tvHelp.Nodes(0)
' Add next nodes
AddNextNodes(XmlDoc.DocumentElement, tNode)
End Sub

Private Sub AddNextNodes(ByVal xmlNode As XmlNode, ByVal treeNode As TreeNode)
Dim xNode As XmlNode
Dim tNode As TreeNode
Dim nodeList As XmlNodeList
If xmlNode.HasChildNodes Then 'The current node has children
nodeList = xmlNode.ChildNodes
' Set all child nodes
For i As Integer = 0 To nodeList.Count - 1
xNode = xmlNode.ChildNodes(i)
' Get the name of node (we want set the head of help item)
If xNode.NodeType = XmlNodeType.Element Then
' Add child nodes to TreeView
treeNode.Nodes.Add(New TreeNode(xNode.Name))
' Add node name to ComboBox
cmbHeading.Items.Add(xNode.Name)
cmbHeading.SelectedIndex = 0
tNode = treeNode.Nodes(i)
' Add next child nodes if any
AddNextNodes(xNode, tNode)
' Set image to the node
Dim strName As String = xNode.Name
Select Case strName
Case "EasyHelp" ' Heading
tNode.ImageIndex = 0
tNode.SelectedImageIndex = 1
Case "Methods" ' Heading
tNode.ImageIndex = 0
tNode.SelectedImageIndex = 1
Case "Properties" ' Heading
tNode.ImageIndex = 0
tNode.SelectedImageIndex = 1
Case Else ' other nodes (Pages)
tNode.ImageIndex = 2
tNode.SelectedImageIndex = 2
End Select
End If
Next
End If
' We shall Remove Introduction, Methods, Properties from ComboBox:
' We do not want to display the (Introduction) in Index
cmbHeading.Items.Remove("Introduction")
' (Methods) hasn't any help
cmbHeading.Items.Remove("Methods")
' (Properties) hasn't any help
cmbHeading.Items.Remove("Properties")
End Sub

The following procedure can read help:

Private Sub ReadHelp(ByVal strNode As String)
Dim textReader As XmlTextReader = Nothing
Dim s As String = ""
Try
textReader = New XmlTextReader(MyHelpFile)
While textReader.Read()
If textReader.Name = strNode Then
s = textReader.ReadString()
txtHelp.Text = s
End If
End While
Catch ex As Exception
MessageBox.Show(ex.Message)
Finally
If textReader.EOF Then textReader.Close()
End Try
End Sub

Remarks

When extracting the files EasyHelp_VBNET.zip you can find:

VB.NET (2008) project with three forms.

• The folder (MyActiveX) includes KGrid.ocx ActiveX control.
• The folder (DataFiles) includes MyMarket.mdb, MyHelp1.xml and MyHelp2.xml.
• The folder (Icons) includes three icons.

I hope this article is useful; if you have any idea, please tell me.