Step 2: Basic construction of VB.NET
This section explains the basic configuration of VB.NET. Please check the details by comparing with the sample.
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In the sample, the DDE related processing is defined in the Common class (Common.vb), and includes processing code for everything from connecting to reading and writing values. The following example shows how to build using the Common class. |
1.Defines the connection process to the DDE server.
Initial processing and connection are performed. Initial processing is performed by "SuDdeInit", and connection is performed by "FnDdeConnect".
'------------------------------------------
' DDE Start & Connect
'------------------------------------------
Private Sub btStart_Click(sender As System.Object, e As System.EventArgs) Handles btStart.Click
Dim vAppName As String = txAppName.Text
Dim vTopiName As String = txTopiName.Text
SuDdeInit(txAppName.Text, txTopiName.Text)
mvConv = FnDdeConnect(vAppName, vTopiName)
If mvConv = 0 Then
MessageBox.Show(vAppName & "/" & vTopiName & vbCrLf & "Connect failure!!", "Error", MessageBoxButtons.OK, MessageBoxIcon.Error)
Exit Sub
End If
btDisConnect.Enabled = True
btRead.Enabled = True
btWrite.Enabled = True
btStart.Enabled = False
End Sub
2.Defines the disconnection process to the DDE server.
Disconnection is performed using "FnDdeConnectEnd".
'------------------------------------------
' DDE DisConnect
'------------------------------------------
Private Sub btDisConnect_Click(sender As System.Object, e As System.EventArgs) Handles btDisConnect.Click
FnDdeConnectEnd(mvConv)
btDisConnect.Enabled = False
btRead.Enabled = False
btWrite.Enabled = False
btStart.Enabled = True
End Sub