How to preserve the contents of the clipboard

Question

Is there a way to preserve the contents of the clipboard? I tried the following code but it doesn't work.

Dim iData As IDataObject = Clipboard.GetDataObject()
...(use clipboard)
Clipboard.SetDataObject(iData)

Thank you.

Answer 1

The easiest way to preserve the contents of the clipboard is to leave the clipboard alone. The clipboard is meant as a temporary storage area for the user, not for applications, so likely what you are trying to do has better solutions than to clobber the clipboard.

Answer 2

You can use the OpenClipboard and CloseClipboard. According to MSDN opening the clipboard will keep other applications from changing the data.

[DllImport("user32.dll", CharSet = CharSet.Auto, ExactSpelling = true)]
    public static extern bool OpenClipboard(IntPtr hWndNewOwner);

    [DllImport("user32.dll", CharSet = CharSet.Auto, ExactSpelling = true)]
    public static extern bool CloseClipboard();

Answer 3

In what way did your code above not work? When I try the equivalent code in C# I get a "CloseClipboard Failed (Exception from HRESULT: 0x800401D4 (CLIPBRD_E_CANT_CLOSE))" exception on calling Clipboard.SetDataObject(iData).

However, the following workaround does the job for me:

// save
Dictionary<String, Object> d = new Dictionary<String, Object>();
IDataObject ido = Clipboard.GetDataObject();
foreach (String s in ido.GetFormats(false))
    d.Add(s, ido.GetData(s));

// ...

// restore
var da = new DataObject();
foreach (String s in d.Keys)
    da.SetData(s, d[s]);
Clipboard.SetDataObject(da);

Answer 4

I agree that the context is important. In my case, I wanted to paste a formatted, dynamically filled-in cover page document onto the front of some dynamically generated text (all in MS Word). Here's the solution I found (using VSTO and C#):

                object start = 0;
                Word.Range startRng = a_TreatedDocument.Range(ref start, ref start);
                startRng.FormattedText = a_CoverPageDocument.Content.FormattedText;

Note, this works with tables and formatted text.