QuickOPC User's Guide and Reference
UAHostAndEndpointDialog Class
Members  Example 



OpcLabs.EasyOpcForms Assembly > OpcLabs.EasyOpc.UA.Forms.Browsing Namespace : UAHostAndEndpointDialog Class
Displays a dialog box from which the user can select a host (computer) and an endpoint of an OPC-UA server residing on it.
Object Model
UAHostAndEndpointDialog ClassEasyUAClientSelector ClassUADiscoveryElement ClassUAEndpointDescriptor ClassHostElement Class
Syntax
'Declaration
 
<CLSCompliantAttribute(True)>
<ComDefaultInterfaceAttribute(OpcLabs.EasyOpc.UA.Forms.Browsing.ComTypes._UAHostAndEndpointDialog)>
<ComVisibleAttribute(True)>
<GuidAttribute("0612DEF8-C143-45F4-A58F-C9C6A2B4AAA6")>
<TypeConverterAttribute(System.ComponentModel.ExpandableObjectConverter)>
<DesignerCategoryAttribute("Component")>
<SerializableAttribute()>
Public NotInheritable Class UAHostAndEndpointDialog 
   Inherits UADialog
   Implements OpcLabs.BaseLib.Forms.ComTypes._FormCommonDialog, OpcLabs.BaseLib.Forms.ComTypes._SizableCommonDialog, OpcLabs.BaseLib.Licensing.ILicensingContextHolder, OpcLabs.EasyOpc.UA.Forms.Browsing.ComTypes._UADialog, OpcLabs.EasyOpc.UA.Forms.Browsing.ComTypes._UAHostAndEndpointDialog, System.ComponentModel.IComponent, System.IDisposable 
'Usage
 
Dim instance As UAHostAndEndpointDialog
[CLSCompliant(true)]
[ComDefaultInterface(OpcLabs.EasyOpc.UA.Forms.Browsing.ComTypes._UAHostAndEndpointDialog)]
[ComVisible(true)]
[Guid("0612DEF8-C143-45F4-A58F-C9C6A2B4AAA6")]
[TypeConverter(System.ComponentModel.ExpandableObjectConverter)]
[DesignerCategory("Component")]
[Serializable()]
public sealed class UAHostAndEndpointDialog : UADialog, OpcLabs.BaseLib.Forms.ComTypes._FormCommonDialog, OpcLabs.BaseLib.Forms.ComTypes._SizableCommonDialog, OpcLabs.BaseLib.Licensing.ILicensingContextHolder, OpcLabs.EasyOpc.UA.Forms.Browsing.ComTypes._UADialog, OpcLabs.EasyOpc.UA.Forms.Browsing.ComTypes._UAHostAndEndpointDialog, System.ComponentModel.IComponent, System.IDisposable  
[CLSCompliant(true)]
[ComDefaultInterface(OpcLabs.EasyOpc.UA.Forms.Browsing.ComTypes._UAHostAndEndpointDialog)]
[ComVisible(true)]
[Guid("0612DEF8-C143-45F4-A58F-C9C6A2B4AAA6")]
[TypeConverter(System.ComponentModel.ExpandableObjectConverter)]
[DesignerCategory("Component")]
[Serializable()]
public ref class UAHostAndEndpointDialog sealed : public UADialog, OpcLabs.BaseLib.Forms.ComTypes._FormCommonDialog, OpcLabs.BaseLib.Forms.ComTypes._SizableCommonDialog, OpcLabs.BaseLib.Licensing.ILicensingContextHolder, OpcLabs.EasyOpc.UA.Forms.Browsing.ComTypes._UADialog, OpcLabs.EasyOpc.UA.Forms.Browsing.ComTypes._UAHostAndEndpointDialog, System.ComponentModel.IComponent, System.IDisposable  
Remarks

This is a modal dialog box; therefore, when shown, it blocks the rest of the application until the user has made a selection. When a dialog box is displayed modally, no input (keyboard or mouse click) can occur except to objects on the dialog box. The program must hide or close the dialog box (usually in response to some user action) before input to the calling program can occur.

 

In This Topic

General

Icon:

With UAHostAndEndpointDialog, your application can integrate a dialog box from which the user can select a host (computer) and an endpoint of OPC-UA server residing on it. This dialog box combines functions of the Computer Browser Dialog and OPC-UA Endpoint Dialog -  into a single dialog.

In addition, the user can add Host nodes in case the particular computer is not visible on the network, or add OPC-UA Endpoint nodes in case the OPC_UA Server is known to exist but is not returned by OPC-UA discovery feature.

Here is an example of OPC-UA Host and Endpoint dialog in action:

.NET

// This example shows how to let the user browse for a host (computer) and an endpoint of an OPC-UA server residing on it.

using System.Windows.Forms;
using OpcLabs.EasyOpc.UA.Forms.Browsing;

namespace UAFormsDocExamples._UAHostAndEndpointDialog
{
    static class ShowDialog
    {
        public static void Main1(IWin32Window owner)
        {
            var hostAndEndpointDialog = new UAHostAndEndpointDialog
            {
                EndpointDescriptor = {Host = "opcua.demo-this.com"}
            };

            DialogResult dialogResult = hostAndEndpointDialog.ShowDialog(owner);
            if (dialogResult != DialogResult.OK)
                return;

            // Display results
            MessageBox.Show(owner, 
                $"HostElement: {hostAndEndpointDialog.HostElement}\r\n" +
                $"DiscoveryElement: {hostAndEndpointDialog.DiscoveryElement}");
        }
    }
}
# This example shows how to let the user browse for a host (computer) and
# an endpoint of an OPC-UA server residing on it.

using namespace OpcLabs.EasyOpc.UA.Forms.Browsing

# The path below assumes that the current directory is [ProductDir]/Examples-NET/PowerShell/Windows .
Add-Type -Path "../../../Components/Opclabs.QuickOpc/net472/OpcLabs.EasyOpcForms.dll"

# Instantiate the dialog object.
$hostAndEndpointDialog = New-Object UAHostAndEndpointDialog
$hostAndEndpointDialog.EndpointDescriptor.Host = "opcua.demo-this.com"

$dialogResult = $hostAndEndpointDialog.ShowDialog()
if ($dialogResult -ne [System.Windows.Forms.DialogResult]::OK) {
    return
}

# Display results
$hostElement = $hostAndEndpointDialog.HostElement
if ($hostElement -ne $null) {
    Write-Host "HostElement: $($hostElement)"
}
$discoveryElement = $hostAndEndpointDialog.DiscoveryElement
if ($discoveryElement -ne $null) {
    Write-Host "DiscoveryElement: $($discoveryElement)"
}
# This example shows how to let the user browse for a host (computer) and an endpoint of an OPC-UA server residing on it.

# The QuickOPC package is needed. Install it using "pip install opclabs_quickopc".
import opclabs_quickopc

# Import .NET namespaces.
from System.Windows.Forms import *
from OpcLabs.EasyOpc.UA.Forms.Browsing import *


hostAndEndpointDialog = UAHostAndEndpointDialog()
hostAndEndpointDialog.EndpointDescriptor.Host = 'opcua.demo-this.com'

dialogResult = hostAndEndpointDialog.ShowDialog()
print(dialogResult)
if dialogResult != DialogResult.OK:
    exit()

# Display results.
print('HostElement: ', hostAndEndpointDialog.HostElement, sep='')
print('DiscoveryElement: ', hostAndEndpointDialog.DiscoveryElement, sep='')

print('Finished.')

COM

// This example shows how to let the user browse for a host (computer) and an endpoint of an OPC-UA server residing on it.

#include "stdafx.h"    // Includes "QuickOpc.h", and other commonly used files
#include "ShowDialog.h"

namespace _UAHostAndEndpointDialog
{
    void ShowDialog::Main()
    {
        // Initialize the COM library
        CoInitializeEx(NULL, COINIT_MULTITHREADED);
        {
            // 
            _UAHostAndEndpointDialogPtr HostAndEndpointDialogPtr(__uuidof(UAHostAndEndpointDialog));

            //
            HostAndEndpointDialogPtr->EndpointDescriptor->Host = L"opcua.demo-this.com";

            // 
            DialogResult dialogResult = HostAndEndpointDialogPtr->ShowDialog(NULL);
            _tprintf(_T("%d\n"), dialogResult);

            if (dialogResult == 1/*OK*/)
            {
                // Display results
                _HostElementPtr hostElementPtr = HostAndEndpointDialogPtr->HostElement;
                _tprintf(_T("HostElement: %s\n"), (hostElementPtr == NULL) ? _T("") : (LPCTSTR)CW2CT(hostElementPtr->ToString));
                _UADiscoveryElementPtr discoveryElementPtr = HostAndEndpointDialogPtr->DiscoveryElement;
                _tprintf(_T("DiscoveryElement: %s\n"), (discoveryElementPtr == NULL) ? _T("") : (LPCTSTR)CW2CT(discoveryElementPtr->ToString));
            }
        }
         // Release all interface pointers BEFORE calling CoUninitialize()
        CoUninitialize();
    }
}
// This example shows how to let the user browse for a host (computer) and
// an endpoint of an OPC-UA server residing on it.

class procedure ShowDialog.Main;
var
  HostAndEndpointDialog: UAHostAndEndpointDialog;
begin
  // Instantiate the dialog object
  HostAndEndpointDialog := CoUAHostAndEndpointDialog.Create;

  HostAndEndpointDialog.EndpointDescriptor.Host := 'opcua.demo-this.com';

  HostAndEndpointDialog.ShowDialog(nil);
  // IMPROVE: check the dialog result

  // Display results
  // IMPROVE: check the nullness of HostAndEndpointDialog.HostElement
  WriteLn('HostElement: ', HostAndEndpointDialog.HostElement.ToString);
  // IMPROVE: check the nullness of HostAndEndpointDialog.DiscoveryElement
  WriteLn('DiscoveryElement: ', HostAndEndpointDialog.DiscoveryElement.ToString);
end;
// This example shows how to let the user browse for a host (computer) and
// an endpoint of an OPC-UA server residing on it.

class procedure ShowDialog.Main;
var
  HostAndEndpointDialog: OpcLabs_EasyOpcForms_TLB._UAHostAndEndpointDialog;
  DialogResult: System_Windows_Forms_TLB.DialogResult;
  HostElement: OpcLabs_BaseLib_TLB.HostElement;
  DiscoveryElement: OpcLabs_EasyOpcUA_TLB.UADiscoveryElement;
begin
  // Instantiate the dialog object
  HostAndEndpointDialog := CoUAHostAndEndpointDialog.Create;

  HostAndEndpointDialog.EndpointDescriptor.Host := 'opcua.demo-this.com';

  DialogResult := HostAndEndpointDialog.ShowDialog(nil);
  WriteLn(DialogResult);

  if DialogResult <> DialogResult_OK then
    Exit;

  // Display results
  HostElement := HostAndEndpointDialog.HostElement;
  if HostElement <> nil then
    WriteLn('HostElement: ', HostElement.ToString);
  DiscoveryElement := HostAndEndpointDialog.DiscoveryElement;
  if DiscoveryElement <> nil then
    WriteLn('DiscoveryElement: ', DiscoveryElement.ToString);
end;
Rem This example shows how to let the user browse for a host (computer) and an endpoint of an OPC-UA server residing on it.

Private Sub ShowDialog_Main_Command_Click()
    OutputText = ""

    Dim HostAndEndpointDialog As New UAHostAndEndpointDialog
    HostAndEndpointDialog.endpointDescriptor.Host = "opcua.demo-this.com"
    
    Dim DialogResult
    DialogResult = HostAndEndpointDialog.ShowDialog
    
    OutputText = OutputText & DialogResult & vbCrLf
    If DialogResult <> 1 Then   ' OK
        Exit Sub
    End If
    
    ' Display results
    Dim HostElement As HostElement
    Set HostElement = HostAndEndpointDialog.HostElement
    If Not HostElement Is Nothing Then
        OutputText = OutputText & "HostElement: " & HostElement & vbCrLf
    End If
    Dim DiscoveryElement As UADiscoveryElement
    Set DiscoveryElement = HostAndEndpointDialog.DiscoveryElement
    If Not DiscoveryElement Is Nothing Then
        OutputText = OutputText & "DiscoveryElement: " & DiscoveryElement & vbCrLf
    End If
End Sub
Rem This example shows how to let the user browse for a host (computer) and an endpoint of an OPC-UA server residing on it.

Option Explicit

Const DialogResult_OK = 1

Dim HostAndEndpointDialog: Set HostAndEndpointDialog = CreateObject("OpcLabs.EasyOpc.UA.Forms.Browsing.UAHostAndEndpointDialog")
HostAndEndpointDialog.EndpointDescriptor.Host = "opcua.demo-this.com"

Dim dialogResult: dialogResult = HostAndEndpointDialog.ShowDialog
WScript.Echo dialogResult

If dialogResult <> DialogResult_OK Then
    WScript.Quit
End If

' Display results
WScript.Echo "HostElement: " & HostAndEndpointDialog.HostElement
WScript.Echo "DiscoveryElement: " & HostAndEndpointDialog.DiscoveryElement

 

Advanced

If you want to change the parameters of the client object the component uses to perform its OPC operations, you can use the ClientSelector Property.

 

 

Example

.NET

COM

// This example shows how to let the user browse for a host (computer) and an endpoint of an OPC-UA server residing on it.

using System.Windows.Forms;
using OpcLabs.EasyOpc.UA.Forms.Browsing;

namespace UAFormsDocExamples._UAHostAndEndpointDialog
{
    static class ShowDialog
    {
        public static void Main1(IWin32Window owner)
        {
            var hostAndEndpointDialog = new UAHostAndEndpointDialog
            {
                EndpointDescriptor = {Host = "opcua.demo-this.com"}
            };

            DialogResult dialogResult = hostAndEndpointDialog.ShowDialog(owner);
            if (dialogResult != DialogResult.OK)
                return;

            // Display results
            MessageBox.Show(owner, 
                $"HostElement: {hostAndEndpointDialog.HostElement}\r\n" +
                $"DiscoveryElement: {hostAndEndpointDialog.DiscoveryElement}");
        }
    }
}
# This example shows how to let the user browse for a host (computer) and
# an endpoint of an OPC-UA server residing on it.

using namespace OpcLabs.EasyOpc.UA.Forms.Browsing

# The path below assumes that the current directory is [ProductDir]/Examples-NET/PowerShell/Windows .
Add-Type -Path "../../../Components/Opclabs.QuickOpc/net472/OpcLabs.EasyOpcForms.dll"

# Instantiate the dialog object.
$hostAndEndpointDialog = New-Object UAHostAndEndpointDialog
$hostAndEndpointDialog.EndpointDescriptor.Host = "opcua.demo-this.com"

$dialogResult = $hostAndEndpointDialog.ShowDialog()
if ($dialogResult -ne [System.Windows.Forms.DialogResult]::OK) {
    return
}

# Display results
$hostElement = $hostAndEndpointDialog.HostElement
if ($hostElement -ne $null) {
    Write-Host "HostElement: $($hostElement)"
}
$discoveryElement = $hostAndEndpointDialog.DiscoveryElement
if ($discoveryElement -ne $null) {
    Write-Host "DiscoveryElement: $($discoveryElement)"
}
# This example shows how to let the user browse for a host (computer) and an endpoint of an OPC-UA server residing on it.

# The QuickOPC package is needed. Install it using "pip install opclabs_quickopc".
import opclabs_quickopc

# Import .NET namespaces.
from System.Windows.Forms import *
from OpcLabs.EasyOpc.UA.Forms.Browsing import *


hostAndEndpointDialog = UAHostAndEndpointDialog()
hostAndEndpointDialog.EndpointDescriptor.Host = 'opcua.demo-this.com'

dialogResult = hostAndEndpointDialog.ShowDialog()
print(dialogResult)
if dialogResult != DialogResult.OK:
    exit()

# Display results.
print('HostElement: ', hostAndEndpointDialog.HostElement, sep='')
print('DiscoveryElement: ', hostAndEndpointDialog.DiscoveryElement, sep='')

print('Finished.')
// This example shows how to let the user browse for a host (computer) and an endpoint of an OPC-UA server residing on it.

#include "stdafx.h"    // Includes "QuickOpc.h", and other commonly used files
#include "ShowDialog.h"

namespace _UAHostAndEndpointDialog
{
    void ShowDialog::Main()
    {
        // Initialize the COM library
        CoInitializeEx(NULL, COINIT_MULTITHREADED);
        {
            // 
            _UAHostAndEndpointDialogPtr HostAndEndpointDialogPtr(__uuidof(UAHostAndEndpointDialog));

            //
            HostAndEndpointDialogPtr->EndpointDescriptor->Host = L"opcua.demo-this.com";

            // 
            DialogResult dialogResult = HostAndEndpointDialogPtr->ShowDialog(NULL);
            _tprintf(_T("%d\n"), dialogResult);

            if (dialogResult == 1/*OK*/)
            {
                // Display results
                _HostElementPtr hostElementPtr = HostAndEndpointDialogPtr->HostElement;
                _tprintf(_T("HostElement: %s\n"), (hostElementPtr == NULL) ? _T("") : (LPCTSTR)CW2CT(hostElementPtr->ToString));
                _UADiscoveryElementPtr discoveryElementPtr = HostAndEndpointDialogPtr->DiscoveryElement;
                _tprintf(_T("DiscoveryElement: %s\n"), (discoveryElementPtr == NULL) ? _T("") : (LPCTSTR)CW2CT(discoveryElementPtr->ToString));
            }
        }
         // Release all interface pointers BEFORE calling CoUninitialize()
        CoUninitialize();
    }
}
// This example shows how to let the user browse for a host (computer) and
// an endpoint of an OPC-UA server residing on it.

class procedure ShowDialog.Main;
var
  HostAndEndpointDialog: OpcLabs_EasyOpcForms_TLB._UAHostAndEndpointDialog;
  DialogResult: System_Windows_Forms_TLB.DialogResult;
  HostElement: OpcLabs_BaseLib_TLB.HostElement;
  DiscoveryElement: OpcLabs_EasyOpcUA_TLB.UADiscoveryElement;
begin
  // Instantiate the dialog object
  HostAndEndpointDialog := CoUAHostAndEndpointDialog.Create;

  HostAndEndpointDialog.EndpointDescriptor.Host := 'opcua.demo-this.com';

  DialogResult := HostAndEndpointDialog.ShowDialog(nil);
  WriteLn(DialogResult);

  if DialogResult <> DialogResult_OK then
    Exit;

  // Display results
  HostElement := HostAndEndpointDialog.HostElement;
  if HostElement <> nil then
    WriteLn('HostElement: ', HostElement.ToString);
  DiscoveryElement := HostAndEndpointDialog.DiscoveryElement;
  if DiscoveryElement <> nil then
    WriteLn('DiscoveryElement: ', DiscoveryElement.ToString);
end;
Rem This example shows how to let the user browse for a host (computer) and an endpoint of an OPC-UA server residing on it.

Private Sub ShowDialog_Main_Command_Click()
    OutputText = ""

    Dim HostAndEndpointDialog As New UAHostAndEndpointDialog
    HostAndEndpointDialog.endpointDescriptor.Host = "opcua.demo-this.com"
    
    Dim DialogResult
    DialogResult = HostAndEndpointDialog.ShowDialog
    
    OutputText = OutputText & DialogResult & vbCrLf
    If DialogResult <> 1 Then   ' OK
        Exit Sub
    End If
    
    ' Display results
    Dim HostElement As HostElement
    Set HostElement = HostAndEndpointDialog.HostElement
    If Not HostElement Is Nothing Then
        OutputText = OutputText & "HostElement: " & HostElement & vbCrLf
    End If
    Dim DiscoveryElement As UADiscoveryElement
    Set DiscoveryElement = HostAndEndpointDialog.DiscoveryElement
    If Not DiscoveryElement Is Nothing Then
        OutputText = OutputText & "DiscoveryElement: " & DiscoveryElement & vbCrLf
    End If
End Sub
Rem This example shows how to let the user browse for a host (computer) and an endpoint of an OPC-UA server residing on it.

Option Explicit

Const DialogResult_OK = 1

Dim HostAndEndpointDialog: Set HostAndEndpointDialog = CreateObject("OpcLabs.EasyOpc.UA.Forms.Browsing.UAHostAndEndpointDialog")
HostAndEndpointDialog.EndpointDescriptor.Host = "opcua.demo-this.com"

Dim dialogResult: dialogResult = HostAndEndpointDialog.ShowDialog
WScript.Echo dialogResult

If dialogResult <> DialogResult_OK Then
    WScript.Quit
End If

' Display results
WScript.Echo "HostElement: " & HostAndEndpointDialog.HostElement
WScript.Echo "DiscoveryElement: " & HostAndEndpointDialog.DiscoveryElement
Inheritance Hierarchy

System.Object
   System.MarshalByRefObject
      System.ComponentModel.Component
         System.Windows.Forms.CommonDialog
            OpcLabs.BaseLib.Forms.ConcreteCommonDialog
               OpcLabs.BaseLib.Forms.FormCommonDialog
                  OpcLabs.BaseLib.Forms.SizableCommonDialog
                     OpcLabs.EasyOpc.UA.Forms.Browsing.UADialog
                        OpcLabs.EasyOpc.UA.Forms.Browsing.UAHostAndEndpointDialog

Requirements

Target Platforms: .NET Framework: Windows 10 (selected versions), Windows 11 (selected versions), Windows Server 2016, Windows Server 2022; .NET: Linux, macOS, Microsoft Windows

See Also