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 2.0.

To access data from the Clipboard by using versions earlier than .NET Framework 2.0, use the Clipboard.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

1. 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 2.0.

   // 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;
   }
   

   ' 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
   

To retrieve data from the Clipboard in a custom format

1. Use the GetData method with a custom format name. This method is available only in .NET Framework 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 Customer TestCustomFormat
   {
       get
       {
           Clipboard.SetData("CustomerFormat", new Customer("Customer Name"));
           if (Clipboard.ContainsData("CustomerFormat"))
           {
               return Clipboard.GetData("CustomerFormat") as Customer;
           }
           return null;
       }
   }
   

   ' 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 string nameValue = string.Empty;
       public Customer(String name)
       {
           nameValue = name;
       }
       public string Name
       {
           get { return nameValue; }
           set { nameValue = value; }
       }
   }
   

   <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
   

To retrieve data from the Clipboard in multiple formats

1. 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 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);
           }
       }
   }
   

   ' 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 string nameValue = string.Empty;
       public Customer(String name)
       {
           nameValue = name;
       }
       public string Name
       {
           get { return nameValue; }
           set { nameValue = value; }
       }
   }
   

   <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
   

See also

• Drag-and-Drop Operations and Clipboard Support
• How to: Add Data to the Clipboard