Clipboard event C#

c# clipboard
wm_clipboardupdate
c# clipboard console application
copy to clipboard c# web application
get data from clipboard c#
c# paste from clipboard
c# clipboard .net core
wm_drawclipboard

Is there a clipboard changed or updated event that i can access through C#?

I think you'll have to use some p/invoke:

[DllImport("User32.dll", CharSet=CharSet.Auto)]
public static extern IntPtr SetClipboardViewer(IntPtr hWndNewViewer);

See this article on how to set up a clipboard monitor in c#

Basically you register your app as a clipboard viewer using

_ClipboardViewerNext = SetClipboardViewer(this.Handle);

and then you will recieve the WM_DRAWCLIPBOARD message, which you can handle by overriding WndProc:

protected override void WndProc(ref Message m)
{
    switch ((Win32.Msgs)m.Msg)
    {
        case Win32.Msgs.WM_DRAWCLIPBOARD:
        // Handle clipboard changed
        break;
        // ... 
   }
}

(There's more to be done; passing things along the clipboard chain and unregistering your view, but you can get that from the article)

Clipboard.ContentChanged Event (Windows.ApplicationModel , The second code snippet shows the event handler, which enables the app's paste command if the Clipboard contains a bitmap. function RegisterEvents() { // Register a listener for the ContentChanged event. It is called whenever // the clipboard content changes Windows. Public Shared Custom Event ContentChanged As EventHandler(Of Object) Examples. The following example shows how to track changes to the Clipboard. The first code snippet registers a handler for the ContentChanged event. The second code snippet shows the event handler, which enables the app's paste command if the Clipboard contains a bitmap.

For completeness, here's the control I'm using in production code. Just drag from the designer and double click to create the event handler.

using System;
using System.ComponentModel;
using System.Runtime.InteropServices;
using System.Windows.Forms;
using System.Drawing;

namespace ClipboardAssist {

// Must inherit Control, not Component, in order to have Handle
[DefaultEvent("ClipboardChanged")]
public partial class ClipboardMonitor : Control 
{
    IntPtr nextClipboardViewer;

    public ClipboardMonitor()
    {
        this.BackColor = Color.Red;
        this.Visible = false;

        nextClipboardViewer = (IntPtr)SetClipboardViewer((int)this.Handle);
    }

    /// <summary>
    /// Clipboard contents changed.
    /// </summary>
    public event EventHandler<ClipboardChangedEventArgs> ClipboardChanged;

    protected override void Dispose(bool disposing)
    {
        ChangeClipboardChain(this.Handle, nextClipboardViewer);
    }

    [DllImport("User32.dll")]
    protected static extern int SetClipboardViewer(int hWndNewViewer);

    [DllImport("User32.dll", CharSet = CharSet.Auto)]
    public static extern bool ChangeClipboardChain(IntPtr hWndRemove, IntPtr hWndNewNext);

    [DllImport("user32.dll", CharSet = CharSet.Auto)]
    public static extern int SendMessage(IntPtr hwnd, int wMsg, IntPtr wParam, IntPtr lParam);

    protected override void WndProc(ref System.Windows.Forms.Message m)
    {
        // defined in winuser.h
        const int WM_DRAWCLIPBOARD = 0x308;
        const int WM_CHANGECBCHAIN = 0x030D;

        switch (m.Msg)
        {
            case WM_DRAWCLIPBOARD:
                OnClipboardChanged();
                SendMessage(nextClipboardViewer, m.Msg, m.WParam, m.LParam);
                break;

            case WM_CHANGECBCHAIN:
                if (m.WParam == nextClipboardViewer)
                    nextClipboardViewer = m.LParam;
                else
                    SendMessage(nextClipboardViewer, m.Msg, m.WParam, m.LParam);
                break;

            default:
                base.WndProc(ref m);
                break;
        }
    }

    void OnClipboardChanged()
    {
        try
        {
            IDataObject iData = Clipboard.GetDataObject();
            if (ClipboardChanged != null)
            {
                ClipboardChanged(this, new ClipboardChangedEventArgs(iData));
            }

        }
        catch (Exception e)
        {
            // Swallow or pop-up, not sure
            // Trace.Write(e.ToString());
            MessageBox.Show(e.ToString());
        }
    }
}

public class ClipboardChangedEventArgs : EventArgs
{
    public readonly IDataObject DataObject;

    public ClipboardChangedEventArgs(IDataObject dataObject)
    {
        DataObject = dataObject;
    }
}
}

Clipboard Class (System.Windows), Occurs when the contents of the clipboard is updated. /// </summary>. public static event EventHandler ClipboardUpdate;. private static NotificationForm _form​  The ClipboardEvent() constructor also inherits arguments from Event(). type Is a DOMString representing the name of the type of the ClipboardEvent. It is case-sensitive and can be: 'copy', 'cut', or 'paste'. options Optional Options are as follows: clipboardData: A DataTransfer containing the data concerned by the clipboard event.

I had this challenge in WPF and ended up using the approach described below. For windows forms there are excellent examples elsewhere in this answer, such as the ClipboardHelper control.

For WPF we cannot override WndProc, so we have to hook it explicitly with an HwndSource AddHook call using the Source from a window. The clipboard listener still uses the AddClipboardFormatListener native interop call.

Native methods:

internal static class NativeMethods
{
    // See http://msdn.microsoft.com/en-us/library/ms649021%28v=vs.85%29.aspx
    public const int WM_CLIPBOARDUPDATE = 0x031D;
    public static IntPtr HWND_MESSAGE = new IntPtr(-3);

    // See http://msdn.microsoft.com/en-us/library/ms632599%28VS.85%29.aspx#message_only
    [DllImport("user32.dll", SetLastError = true)]
    [return: MarshalAs(UnmanagedType.Bool)]
    public static extern bool AddClipboardFormatListener(IntPtr hwnd);
}

Clipboard Manager class:

using System.Windows;
using System.Windows.Interop;

public class ClipboardManager
{
    public event EventHandler ClipboardChanged;

    public ClipboardManager(Window windowSource)
    {
        HwndSource source = PresentationSource.FromVisual(windowSource) as HwndSource;
        if(source == null)
        {
            throw new ArgumentException(
                "Window source MUST be initialized first, such as in the Window's OnSourceInitialized handler."
                , nameof(windowSource));
        }

        source.AddHook(WndProc);

        // get window handle for interop
        IntPtr windowHandle = new WindowInteropHelper(windowSource).Handle;

        // register for clipboard events
        NativeMethods.AddClipboardFormatListener(windowHandle);
    }

    private void OnClipboardChanged()
    {
        ClipboardChanged?.Invoke(this, EventArgs.Empty);
    }

    private static readonly IntPtr WndProcSuccess = IntPtr.Zero;

    private IntPtr WndProc(IntPtr hwnd, int msg, IntPtr wParam, IntPtr lParam, ref bool handled)
    {
        if (msg == NativeMethods.WM_CLIPBOARDUPDATE)
        {
            OnClipboardChanged();
            handled = true;
        }

        return WndProcSuccess;
    }
}

This gets used in a WPF window by adding the event in OnSourceInitialized or later such as the Window.Loaded event or during operation. (when we have enough information to use the native hooks):

public partial class MainWindow : Window
{
    public MainWindow()
    {
        InitializeComponent();
    }

    protected override void OnSourceInitialized(EventArgs e)
    {
        base.OnSourceInitialized(e);

        // Initialize the clipboard now that we have a window soruce to use
        var windowClipboardManager = new ClipboardManager(this);
        windowClipboardManager.ClipboardChanged += ClipboardChanged;
    }

    private void ClipboardChanged(object sender, EventArgs e)
    {
        // Handle your clipboard update here, debug logging example:
        if (Clipboard.ContainsText())
        {
            Debug.WriteLine(Clipboard.GetText());
        }
    }
}

I'm using this approach in a Path of Exile item analyzer project, as the game exposes item information via the clipboard when you hit Ctrl-C.

https://github.com/ColinDabritz/PoeItemAnalyzer

I hope this helps someone with WPF clipboard change handling!

Clipboard Class (System.Windows.Forms), an event based method OnXXX is usually either private or protected and used to C# 6 syntax for null checking not protect you from case that between the null  One of those tasks—which the "Clipboard ring" in Microsoft Office has made popular—is specifying that your application is notified if the Clipboard changes. This week's installment of .NET Tips & Techniques provides both an overview and a step-by-step example for accomplishing this with .NET and C#.

Ok so this is an old post but we found a solution that seems very simple compared to the current set of answers. We are using WPF and we wanted to have our own custom Commands (in a ContextMenu) enable and disable if the Clipboard contains text. There is already an ApplicationCommands.Cut, Copy and Paste and these commands respond correctly to the clipboard changing. So we just added the following EventHandler.

ApplicationCommands.Paste.CanExecuteChanged += new EventHandler(Paste_CanExecuteChanged);

private void Paste_CanExecuteChanged(object sender, EventArgs e) {
  ourVariable= Clipboard.ContainsText();
}

We actually are controlling the CanExecute on our own Command this way. Works for what we needed and maybe it will help others out there.

Monitor Clipboard changes in C# using , In this week's .NET Tips & Techniques column, Tom Archer illustrates how to correctly monitor the Windows Clipboard from a C# . Public Function SwapClipboardHtmlText( _ ByVal replacementHtmlText As String) As String Dim returnHtmlText As String = Nothing If (Clipboard.ContainsText(TextDataFormat.Html)) Then returnHtmlText = Clipboard.GetText(TextDataFormat.Html) Clipboard.SetText(replacementHtmlText, TextDataFormat.Html) End If Return returnHtmlText End Function

There are multiple ways of doing this but this is my favorite and works for me. I've created a class library so that others may add the project and include the DLL then simply call on it and use it wherever they want within their applications.

This answer was made with the help of this one.

  1. Create Class Library project and name it ClipboardHelper.
  2. Replace the Class1 name with ClipboardMonitor.
  3. Add the below code into it.
  4. Add System.Windows.Forms reference.

More steps under code.

using System;
using System.Windows.Forms;
using System.Threading;
using System.Runtime.InteropServices;

namespace ClipboardHelper
{
    public static class ClipboardMonitor
    {
        public delegate void OnClipboardChangeEventHandler(ClipboardFormat format, object data);
        public static event OnClipboardChangeEventHandler OnClipboardChange;

        public static void Start()
        {
            ClipboardWatcher.Start();
            ClipboardWatcher.OnClipboardChange += (ClipboardFormat format, object data) =>
            {
                if (OnClipboardChange != null)
                    OnClipboardChange(format, data);
            };
        }

        public static void Stop()
        {
            OnClipboardChange = null;
            ClipboardWatcher.Stop();
        }

        class ClipboardWatcher : Form
        {
            // static instance of this form
            private static ClipboardWatcher mInstance;

            // needed to dispose this form
            static IntPtr nextClipboardViewer;

            public delegate void OnClipboardChangeEventHandler(ClipboardFormat format, object data);
            public static event OnClipboardChangeEventHandler OnClipboardChange;

            // start listening
            public static void Start()
            {
                // we can only have one instance if this class
                if (mInstance != null)
                    return;

                var t = new Thread(new ParameterizedThreadStart(x => Application.Run(new ClipboardWatcher())));
                t.SetApartmentState(ApartmentState.STA); // give the [STAThread] attribute
                t.Start();
            }

            // stop listening (dispose form)
            public static void Stop()
            {
                mInstance.Invoke(new MethodInvoker(() =>
                {
                    ChangeClipboardChain(mInstance.Handle, nextClipboardViewer);
                }));
                mInstance.Invoke(new MethodInvoker(mInstance.Close));

                mInstance.Dispose();

                mInstance = null;
            }

            // on load: (hide this window)
            protected override void SetVisibleCore(bool value)
            {
                CreateHandle();

                mInstance = this;

                nextClipboardViewer = SetClipboardViewer(mInstance.Handle);

                base.SetVisibleCore(false);
            }

            [DllImport("User32.dll", CharSet = CharSet.Auto)]
            private static extern IntPtr SetClipboardViewer(IntPtr hWndNewViewer);

            [DllImport("User32.dll", CharSet = CharSet.Auto)]
            private static extern bool ChangeClipboardChain(IntPtr hWndRemove, IntPtr hWndNewNext);

            [DllImport("user32.dll", CharSet = CharSet.Auto)]
            private static extern int SendMessage(IntPtr hwnd, int wMsg, IntPtr wParam, IntPtr lParam);

            // defined in winuser.h
            const int WM_DRAWCLIPBOARD = 0x308;
            const int WM_CHANGECBCHAIN = 0x030D;

            protected override void WndProc(ref Message m)
            {
                switch (m.Msg)
                {
                    case WM_DRAWCLIPBOARD:
                        ClipChanged();
                        SendMessage(nextClipboardViewer, m.Msg, m.WParam, m.LParam);
                        break;

                    case WM_CHANGECBCHAIN:
                        if (m.WParam == nextClipboardViewer)
                            nextClipboardViewer = m.LParam;
                        else
                            SendMessage(nextClipboardViewer, m.Msg, m.WParam, m.LParam);
                        break;

                    default:
                        base.WndProc(ref m);
                        break;
                }
            }

            static readonly string[] formats = Enum.GetNames(typeof(ClipboardFormat));

            private void ClipChanged()
            {
                IDataObject iData = Clipboard.GetDataObject();

                ClipboardFormat? format = null;

                foreach (var f in formats)
                {
                    if (iData.GetDataPresent(f))
                    {
                        format = (ClipboardFormat)Enum.Parse(typeof(ClipboardFormat), f);
                        break;
                    }
                }

                object data = iData.GetData(format.ToString());

                if (data == null || format == null)
                    return;

                if (OnClipboardChange != null)
                    OnClipboardChange((ClipboardFormat)format, data);
            }
        }
    }

    public enum ClipboardFormat : byte
    {
        /// <summary>Specifies the standard ANSI text format. This static field is read-only.
        /// </summary>
        /// <filterpriority>1</filterpriority>
        Text,
        /// <summary>Specifies the standard Windows Unicode text format. This static field
        /// is read-only.</summary>
        /// <filterpriority>1</filterpriority>
        UnicodeText,
        /// <summary>Specifies the Windows device-independent bitmap (DIB) format. This static
        /// field is read-only.</summary>
        /// <filterpriority>1</filterpriority>
        Dib,
        /// <summary>Specifies a Windows bitmap format. This static field is read-only.</summary>
        /// <filterpriority>1</filterpriority>
        Bitmap,
        /// <summary>Specifies the Windows enhanced metafile format. This static field is
        /// read-only.</summary>
        /// <filterpriority>1</filterpriority>
        EnhancedMetafile,
        /// <summary>Specifies the Windows metafile format, which Windows Forms does not
        /// directly use. This static field is read-only.</summary>
        /// <filterpriority>1</filterpriority>
        MetafilePict,
        /// <summary>Specifies the Windows symbolic link format, which Windows Forms does
        /// not directly use. This static field is read-only.</summary>
        /// <filterpriority>1</filterpriority>
        SymbolicLink,
        /// <summary>Specifies the Windows Data Interchange Format (DIF), which Windows Forms
        /// does not directly use. This static field is read-only.</summary>
        /// <filterpriority>1</filterpriority>
        Dif,
        /// <summary>Specifies the Tagged Image File Format (TIFF), which Windows Forms does
        /// not directly use. This static field is read-only.</summary>
        /// <filterpriority>1</filterpriority>
        Tiff,
        /// <summary>Specifies the standard Windows original equipment manufacturer (OEM)
        /// text format. This static field is read-only.</summary>
        /// <filterpriority>1</filterpriority>
        OemText,
        /// <summary>Specifies the Windows palette format. This static field is read-only.
        /// </summary>
        /// <filterpriority>1</filterpriority>
        Palette,
        /// <summary>Specifies the Windows pen data format, which consists of pen strokes
        /// for handwriting software, Windows Forms does not use this format. This static
        /// field is read-only.</summary>
        /// <filterpriority>1</filterpriority>
        PenData,
        /// <summary>Specifies the Resource Interchange File Format (RIFF) audio format,
        /// which Windows Forms does not directly use. This static field is read-only.</summary>
        /// <filterpriority>1</filterpriority>
        Riff,
        /// <summary>Specifies the wave audio format, which Windows Forms does not directly
        /// use. This static field is read-only.</summary>
        /// <filterpriority>1</filterpriority>
        WaveAudio,
        /// <summary>Specifies the Windows file drop format, which Windows Forms does not
        /// directly use. This static field is read-only.</summary>
        /// <filterpriority>1</filterpriority>
        FileDrop,
        /// <summary>Specifies the Windows culture format, which Windows Forms does not directly
        /// use. This static field is read-only.</summary>
        /// <filterpriority>1</filterpriority>
        Locale,
        /// <summary>Specifies text consisting of HTML data. This static field is read-only.
        /// </summary>
        /// <filterpriority>1</filterpriority>
        Html,
        /// <summary>Specifies text consisting of Rich Text Format (RTF) data. This static
        /// field is read-only.</summary>
        /// <filterpriority>1</filterpriority>
        Rtf,
        /// <summary>Specifies a comma-separated value (CSV) format, which is a common interchange
        /// format used by spreadsheets. This format is not used directly by Windows Forms.
        /// This static field is read-only.</summary>
        /// <filterpriority>1</filterpriority>
        CommaSeparatedValue,
        /// <summary>Specifies the Windows Forms string class format, which Windows Forms
        /// uses to store string objects. This static field is read-only.</summary>
        /// <filterpriority>1</filterpriority>
        StringFormat,
        /// <summary>Specifies a format that encapsulates any type of Windows Forms object.
        /// This static field is read-only.</summary>
        /// <filterpriority>1</filterpriority>
        Serializable,
    }
}
  1. In your other projects right click on solution and Add -> Exiting Project -> ClipboardHelper.csproj
  2. On your project go to and right click References -> Add Reference -> Solution -> Select ClipboardHelper.
  3. In your class file of the project type using ClipboardHelper.
  4. You may now type ClipboardMonitor.Start or .Stop or .OnClipboardChanged

    using ClipboardHelper;
    
    namespace Something.Something.DarkSide
    {
        public class MainWindow
        {
    
            public MainWindow()
            {
                InitializeComponent();
    
                Loaded += MainWindow_Loaded;
            }
    
            void MainWindow_Loaded(object sender, RoutedEventArgs e)
            {
                ClipboardMonitor.OnClipboardChange += ClipboardMonitor_OnClipboardChange;
                ClipboardMonitor.Start();
            }               
    
            private void ClipboardMonitor_OnClipboardChange(ClipboardFormat format, object data)
            {
                // Do Something...
            }
    }
    

Monitoring the clipboard, I think you'll have to use some p/invoke: [DllImport("User32.dll", CharSet=CharSet​.Auto)] public static extern IntPtr SetClipboardViewer(IntPtr  In .NET Framework 2.0, the Clipboard class provides additional methods that make it easier to work with the system Clipboard. Call the Clear method to remove all data from the Clipboard. To add data of a particular format to the Clipboard, replacing the existing data, call the appropriate Set Format method, such as SetText , or call the SetData method to specify the format.

C# Tip: Monitoring Clipboard Activity in C#, All events that happen at operating system level such as Clipboard changes, Hot Key pressed event, Foreground window has changed, etc., are  Handle a paste event in c#. I've created a static class numeric Textbox but i wan't to control what the users paste in te textbox.

Clipboard event C#, In other words, while the script above will fire a paste event, the data will not be pasted into the document. 5.2. Clipboard events. 5.2.1. The  You can only access the clipboard when the calling application is in focus on the UI thread (for example, when its CoreWindow is active). Use the CoreWindow.Activated event to track the state of the calling app.

How to Create Clipboard Manager and Get Custom , And then you use the class as: Thanks for your implementation. But it is not Thread Safe, the events will be raised on the thread you created and not on the thread that registered to the event. However, between these two operations, it is possible for another operation to change the content of the clipboard.

Comments
  • what about Control class? Where it is?
  • It's part of WinForms.
  • It works only on the first opened form... say if I have MyForm1 and myForm2, so I open myForm1, then MyForm2, the event ClipboardChanged will be raised only in MyForm1. I mean, in a MDI application...
  • The link is dead. Any backup where you are aware of? +1 nonetheless.
  • For lazy people: Set up a timer which ticks at 1ms. Then, with every tick, check if ur clipboard-content changed. These hooks are raising virus and trojan alerts on my computer.
  • It passes every windows MSG to the form and make it so hard to debug the code
  • Likewise, SharpClipboard as a library could be of more benefit as it encapsulates the same features into one fine component library. You can then access its ClipboardChanged event and detect various data-formats when they're cut/copied.
  • Great Job! Your event calling code is not thread safe, though. You should either create a local copy, or init the event with an empty delegate. You also forgot the 'event' keyword in the definition of ClipboardChanged :)
  • @ohadsc Thank you for the corrections. As far as I know, WndProc is called on the UI thread. Since the class derives from Control, clients should call it on UI thread as well.
  • It works only on the first opened form... say if I have MyForm1 and myForm2, so I open myForm1, then MyForm2, the event ClipboardChanged will be raised only in MyForm1... I mean, in a MDI application...
  • Somehow your call to SetClipboardViewer sets the Win32 Error Code 1400: "Invalid window handle.". But it still works. This seems a little strange to me.