Question

VC如何将指定的字符串复制到剪贴版里

比如有个按钮，点了以后实现功能把

CString a =“1234”复制到CTRL+C那里面

Answer 1

如果是 MFC 应用程序，而且是要把编辑框内容复制到剪贴板，直接调用CEdit::Copy 即可。

如果是其他情况，MSDN 有详细说明:

Copying Information to the Clipboard

In the Label application, the application-defined EditCopy function copies the current selection to the clipboard. This function does the following:

Opens the clipboard by calling the OpenClipboard function.
调用 OpenClipboard 打开剪贴板

Empties the clipboard by calling the EmptyClipboard function.
调用 EmptyClipboard 清除剪贴板内容

Calls the SetClipboardData function once for each clipboard format the application provides.
调用 SetClipboardData 将内容放置到剪贴板上

Closes the clipboard by calling the CloseClipboard function.
调用 CloseClipboard 关闭剪贴板

Depending on the current selection, the EditCopy function either copies a range of text or copies an application-defined structure representing an entire label. The structure, called LABELBOX, is defined as follows.

BOOL WINAPI EditCopy(VOID)
{
PLABELBOX pbox;
LPTSTR lptstrCopy;
HGLOBAL hglbCopy;
int ich1, ich2, cch;

if (hwndSelected == NULL)
return FALSE;

// Open the clipboard, and empty it.

if (!OpenClipboard(hwndMain))
return FALSE;
EmptyClipboard();

// Get a pointer to the structure for the selected label.

pbox = (PLABELBOX) GetWindowLong(hwndSelected, 0);

// If text is selected, copy it using the CF_TEXT format.

if (pbox->fEdit)
{
if (pbox->ichSel == pbox->ichCaret) // zero length
{
CloseClipboard(); // selection
return FALSE;
}

if (pbox->ichSel < pbox->ichCaret)
{
ich1 = pbox->ichSel;
ich2 = pbox->ichCaret;
}
else
{
ich1 = pbox->ichCaret;
ich2 = pbox->ichSel;
}
cch = ich2 - ich1;

// Allocate a global memory object for the text.

hglbCopy = GlobalAlloc(GMEM_MOVEABLE,
(cch + 1) * sizeof(TCHAR));
if (hglbCopy == NULL)
{
CloseClipboard();
return FALSE;
}

// Lock the handle and copy the text to the buffer.

lptstrCopy = GlobalLock(hglbCopy);
memcpy(lptstrCopy, &pbox->atchLabel[ich1],
cch * sizeof(TCHAR));
lptstrCopy[cch] = (TCHAR) 0; // null character
GlobalUnlock(hglbCopy);

// Place the handle on the clipboard.

SetClipboardData(CF_TEXT, hglbCopy);
}

// If no text is selected, the label as a whole is copied.

else
{
// Save a copy of the selected label as a local memory
// object. This copy is used to render data on request.
// It is freed in response to the WM_DESTROYCLIPBOARD
// message.

pboxLocalClip = (PLABELBOX) LocalAlloc(
LMEM_FIXED,
sizeof(LABELBOX)
);
if (pboxLocalClip == NULL)
{
CloseClipboard();
return FALSE;
}
memcpy(pboxLocalClip, pbox, sizeof(LABELBOX));
pboxLocalClip->fSelected = FALSE;
pboxLocalClip->fEdit = FALSE;

// Place a registered clipboard format, the owner-display
// format, and the CF_TEXT format on the clipboard using
// delayed rendering.

SetClipboardData(uLabelFormat, NULL);
SetClipboardData(CF_OWNERDISPLAY, NULL);
SetClipboardData(CF_TEXT, NULL);
}

// Close the clipboard.
CloseClipboard();

return TRUE;
}