RoyalApps.Community.Rdp.WinForms 1.4.4

RDP Control

RoyalApps.Community.RDP contains projects/packages to easily embed/use Microsoft RDP ActiveX wrapped in MsRdpEx in a Windows (WinForms) application.

Getting Started

Installation

You should install the RoyalApps.Community.RDP.WinForms with NuGet:

Install-Package RoyalApps.Community.RDP.WinForms

or via the command line interface:

dotnet add package RoyalApps.Community.RDP.WinForms

Using the RdpControl

Add Control

Place the RdpControl on a form or in a container control (user control, tab control, etc.) and set the Dock property to DockStyle.Fill

Set Properties

To configure all RDP relevant settings, use the properties of the RdpClientConfiguration class which is accessible through the RdpControl.RdpConfiguration property.

Connect and Disconnect

Once the configuration is set, call:

RdpControl.Connect();

to start a connection.

To disconnect, simply call:

RdpControl.Disconnect();

Subscribe to Events

When the connection has been established, the Connected event is raised.

The Disconnected event is raised when:

• the connection couldn't be established (server not reachable, incorrect credentials)
• the connection has been interrupted (network failure)
• the connection was closed by the user (logoff or disconnect)

The DisconnectedEventArgs may have an error code or error message for more information.

Exploring the Demo Application

The demo application is quite simple. The Remote Desktop menu has the following items:

Connect

Starts the remote desktop connection.

Disconnect

Stops the remote desktop connection.

Settings

Shows a window with all the settings from the RdpClientConfiguration class. Edit/change the settings before you click on Connect.

Notable Features

MsRdpEx Gateway Isolation and Logging

V1 loads MsRdpEx hooks for every connection. MsRdpEx 2026.9.21.0 enables gateway RPC binding isolation by default, addressing failures when a second embedded RD Gateway connection opens in the same process. Logging and capture need not be enabled. To disable isolation, set MSRDPEX_GATEWAY_UNIQUE_BINDING=0 before MsRdpEx loads. The setting is process-wide; existing bindings retain their behavior.

Set RdpConfiguration.LogEnabled, LogLevel, and LogFilePath before connecting to configure native diagnostics. A connection with logging disabled leaves the implicit logging configuration unset, allowing a later connection to enable it. All controls should use the same process-wide logging configuration.

For explicit runtime changes, use the existing RoyalApps.Community.Rdp.WinForms.Controls.RdpControl.ConfigureProcessWideMsRdpExLogging(enabled, level, filePath, logger) method. Explicit settings take precedence over subsequent connection settings. After explicitly disabling logging, use this method to enable it again. The updated native library supports enabling logging after DLL load and changing the log level. In MsRdpEx 2026.9.21.0, the destination is fixed after the first successful log open; disabling logging retains the native file handle until process exit. Choose the destination before enabling logging and reuse it for runtime changes.

Legacy COM Interop

V1 retains its public API and requires MsRdpEx's legacy interop assemblies. Applications that configure interop explicitly must use:

<PropertyGroup>
  <MsRdpExComInterop>Legacy</MsRdpExComInterop>
  <MsRdpExGeneratedWinForms>false</MsRdpExGeneratedWinForms>
</PropertyGroup>

Generated and disabled interop modes are rejected at build time. The repository's NuGet.Config uses nuget.org only and clears inherited sources and source mappings without changing machine or user feed settings.

Use Microsoft Remote Desktop Client

One of the most interesting possibilities of this package is to use the Microsoft's modern Remote Desktop Client (RDC) instead of the Terminal Services Client (MSTSC) which ships with Windows. Just set RdpClientConfiguration.UseMsRdc to true and ensure that the Remote Desktop Client is installed from the Microsoft Store.

Auto Expand Desktop Size

If DesktopWidth and DesktopHeight properties are set to 0 (default), the remote desktop size is determined by the container size the control is placed on.

Resize Behavior

You can set the RdpClientConfiguration.Display.ResizeBehavior property to one of the following:

• Scrollbars: displays scrollbars when the container (form) size decreases.
• SmartSizing: scales down the remote desktop while preserving the original desktop size.
• SmartReconnect: adapts the remote desktop size to accordingly when the container (form) size changes.

Call the RdpControl.SetResizeBehavior(ResizeBehavior resizeBehavior) method to change the behavior while connected.

Scaling and Zoom

Auto Scaling

Setting the RdpClientConfiguration.Display.AutoScaling to true will automatically adapt the scaling factor to system's the DPI scaling during connect.

Alternatively you can provide the RdpClientConfiguration.Display.InitialZoomLevel to set a custom zoom level.

Changing Zoom Level

While connected you can use the methods RdpControl.ZoomIn() and RdpControl.ZoomOut() to change the zoom level.

Local Scaling

Setting RdpClientConfiguration.Display.UseLocalScaling to true will scale on the client side instead of settings the remote zoom level (DPI settings). With this enabled, SmartSizing as ResizeBehavior will not be possible.

Acknowledgements

Special thanks to Marc-André Moreau / Devolutions for providing the MsRdpEx package.