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How to: Retrieve Data from the Clipboard

The Clipboard class provides methods that you can use to interact with the Windows operating system Clipboard feature. Many applications use the Clipboard as a temporary repository for data. For example, word processors use the Clipboard during cut-and-paste operations. The Clipboard is also useful for transferring information from one application to another.

Some applications store data on the Clipboard in multiple formats to increase the number of other applications that can potentially use the data. A Clipboard format is a string that identifies the format. An application that uses the identified format can retrieve the associated data on the Clipboard. The DataFormats class provides predefined format names for your use. You can also use your own format names or use an object's type as its format. For information about adding data to the Clipboard, see How to: Add Data to the Clipboard.

To determine whether the Clipboard contains data in a particular format, use one of the ContainsFormat methods or the GetData method. To retrieve data from the Clipboard, use one of the GetFormat methods or the GetData method. These methods are new in .NET Framework version 2.0.

To access data from the Clipboard by using versions earlier than .NET Framework 2.0, use the GetDataObject method and call the methods of the returned IDataObject. To determine whether a particular format is available in the returned object, for example, call the GetDataPresent method.

Note

All Windows-based applications share the system Clipboard. Therefore, the contents are subject to change when you switch to another application.

The Clipboard class can only be used in threads set to single thread apartment (STA) mode. To use this class, ensure that your Main method is marked with the STAThreadAttribute attribute.

To retrieve data from the Clipboard in a single, common format

  • Use the GetAudioStream, GetFileDropList, GetImage, or GetText method. Optionally, use the corresponding ContainsFormat methods first to determine whether data is available in a particular format. These methods are available only in .NET Framework version 2.0.

    ' Demonstrates SetAudio, ContainsAudio, and GetAudioStream.
    Public Function SwapClipboardAudio( _
        ByVal replacementAudioStream As System.IO.Stream) _
        As System.IO.Stream
    
        Dim returnAudioStream As System.IO.Stream = Nothing
    
        If (Clipboard.ContainsAudio()) Then
            returnAudioStream = Clipboard.GetAudioStream()
            Clipboard.SetAudio(replacementAudioStream)
        End If
    
        Return returnAudioStream
    
    End Function
    
    ' Demonstrates SetFileDropList, ContainsFileDroList, and GetFileDropList
    Public Function SwapClipboardFileDropList(ByVal replacementList _
        As System.Collections.Specialized.StringCollection) _
        As System.Collections.Specialized.StringCollection
    
        Dim returnList As System.Collections.Specialized.StringCollection _
            = Nothing
    
        If Clipboard.ContainsFileDropList() Then
    
            returnList = Clipboard.GetFileDropList()
            Clipboard.SetFileDropList(replacementList)
        End If
    
        Return returnList
    
    End Function
    
    ' Demonstrates SetImage, ContainsImage, and GetImage.
    Public Function SwapClipboardImage( _
        ByVal replacementImage As System.Drawing.Image) _
        As System.Drawing.Image
    
        Dim returnImage As System.Drawing.Image = Nothing
    
        If Clipboard.ContainsImage() Then
            returnImage = Clipboard.GetImage()
            Clipboard.SetImage(replacementImage)
        End If
    
        Return returnImage
    End Function
    
    ' Demonstrates SetText, ContainsText, and GetText.
    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
    
    // Demonstrates SetAudio, ContainsAudio, and GetAudioStream.
    public System.IO.Stream SwapClipboardAudio(
        System.IO.Stream replacementAudioStream)
    {
        System.IO.Stream returnAudioStream = null;
        if (Clipboard.ContainsAudio())
        {
            returnAudioStream = Clipboard.GetAudioStream();
            Clipboard.SetAudio(replacementAudioStream);
        }
        return returnAudioStream;
    }
    
    // Demonstrates SetFileDropList, ContainsFileDroList, and GetFileDropList
    public System.Collections.Specialized.StringCollection
        SwapClipboardFileDropList(
        System.Collections.Specialized.StringCollection replacementList)
    {
        System.Collections.Specialized.StringCollection returnList = null;
        if (Clipboard.ContainsFileDropList())
        {
            returnList = Clipboard.GetFileDropList();
            Clipboard.SetFileDropList(replacementList);
        }
        return returnList;
    }
    
    // Demonstrates SetImage, ContainsImage, and GetImage.
    public System.Drawing.Image SwapClipboardImage(
        System.Drawing.Image replacementImage)
    {
        System.Drawing.Image returnImage = null;
        if (Clipboard.ContainsImage())
        {
            returnImage = Clipboard.GetImage();
            Clipboard.SetImage(replacementImage);
        }
        return returnImage;
    }
    
    // Demonstrates SetText, ContainsText, and GetText.
    public String SwapClipboardHtmlText(String replacementHtmlText)
    {
        String returnHtmlText = null;
        if (Clipboard.ContainsText(TextDataFormat.Html))
        {
            returnHtmlText = Clipboard.GetText(TextDataFormat.Html);
            Clipboard.SetText(replacementHtmlText, TextDataFormat.Html);
        }
        return returnHtmlText;
    }
    

To retrieve data from the Clipboard in a custom format

  • Use the GetData method with a custom format name. This method is available only in .NET Framework version 2.0.

    You can also use predefined format names with the SetData method. For more information, see DataFormats.

    ' Demonstrates SetData, ContainsData, and GetData
    ' using a custom format name and a business object.
    Public ReadOnly Property TestCustomFormat() As Customer
        Get
            Clipboard.SetData("CustomerFormat", New Customer("Customer Name"))
    
            If Clipboard.ContainsData("CustomerFormat") Then
                Return CType(Clipboard.GetData("CustomerFormat"), Customer)
            End If
    
            Return Nothing
        End Get
    End Property
    
    
    ...
    
    
    <Serializable()> Public Class Customer
    
        Private nameValue As String = String.Empty
    
        Public Sub New(ByVal name As String)
            nameValue = name
        End Sub
    
        Public Property Name() As String
            Get
                Return nameValue
            End Get
            Set(ByVal value As String)
                nameValue = value
            End Set
        End Property
    
    End Class
    
    // Demonstrates SetData, ContainsData, and GetData
    // using a custom format name and a business object.
    public Customer TestCustomFormat
    {
        get
        {
            Clipboard.SetData("CustomerFormat", new Customer("Customer Name"));
            if (Clipboard.ContainsData("CustomerFormat")) 
            {
                return Clipboard.GetData("CustomerFormat") as Customer;
            }
            return null;
        }
    }
    
    
    ...
    
    
    [Serializable]
    public class Customer
    {
        private string nameValue = string.Empty;
        public Customer(String name)
        {
            nameValue = name;
        }
        public string Name
        {
            get { return nameValue; }
            set { nameValue = value; }
        }
    }
    

To retrieve data from the Clipboard in multiple formats

  • Use the GetDataObject method. You must use this method to retrieve data from the Clipboard on versions earlier than .NET Framework 2.0.

    ' Demonstrates how to use a DataObject to add
    ' data to the Clipboard in multiple formats.
    Public Sub TestClipboardMultipleFormats()
    
        Dim data As New DataObject()
    
        ' Add a Customer object using the type as the format.
        data.SetData(New Customer("Customer as Customer object"))
    
        ' Add a ListViewItem object using a custom format name.
        data.SetData("CustomFormat", _
            New ListViewItem("Customer as ListViewItem"))
    
        Clipboard.SetDataObject(data)
        Dim retrievedData As DataObject = _
            CType(Clipboard.GetDataObject(), DataObject)
    
        If (retrievedData.GetDataPresent("CustomFormat")) Then
    
            Dim item As ListViewItem = _
                TryCast(retrievedData.GetData("CustomFormat"), ListViewItem)
    
            If item IsNot Nothing Then
                MessageBox.Show(item.Text)
            End If
    
        End If
    
        If retrievedData.GetDataPresent(GetType(Customer)) Then
    
            Dim customer As Customer = _
                CType(retrievedData.GetData(GetType(Customer)), Customer)
    
            If customer IsNot Nothing Then
    
                MessageBox.Show(customer.Name)
            End If
    
        End If
    
    End Sub
    
    
    ...
    
    
    <Serializable()> Public Class Customer
    
        Private nameValue As String = String.Empty
    
        Public Sub New(ByVal name As String)
            nameValue = name
        End Sub
    
        Public Property Name() As String
            Get
                Return nameValue
            End Get
            Set(ByVal value As String)
                nameValue = value
            End Set
        End Property
    
    End Class
    
    // Demonstrates how to use a DataObject to add
    // data to the Clipboard in multiple formats.
    public void TestClipboardMultipleFormats()
    {
        DataObject data = new DataObject();
    
        // Add a Customer object using the type as the format.
        data.SetData(new Customer("Customer as Customer object"));
    
        // Add a ListViewItem object using a custom format name.
        data.SetData("CustomFormat", 
            new ListViewItem("Customer as ListViewItem"));
    
        Clipboard.SetDataObject(data);
        DataObject retrievedData = (DataObject)Clipboard.GetDataObject();
    
        if (retrievedData.GetDataPresent("CustomFormat"))
        {
            ListViewItem item = 
                retrievedData.GetData("CustomFormat") as ListViewItem;
            if (item != null)
            {
                MessageBox.Show(item.Text);
            }
        }
    
        if (retrievedData.GetDataPresent(typeof(Customer)))
        {
            Customer customer = 
                retrievedData.GetData(typeof(Customer)) as Customer;
            if (customer != null)
            {
                MessageBox.Show(customer.Name);
            }
        }
    }
    
    
    ...
    
    
    [Serializable]
    public class Customer
    {
        private string nameValue = string.Empty;
        public Customer(String name)
        {
            nameValue = name;
        }
        public string Name
        {
            get { return nameValue; }
            set { nameValue = value; }
        }
    }
    

See Also

Tasks

How to: Add Data to the Clipboard

Other Resources

Drag-and-Drop Operations and Clipboard Support