关于OLE剪贴板的小问题

[tpProgramer]

我使用OLE剪贴板剪贴一段CString文字，设置格式CF_TEXT，但是在代码中调用 COleDataObject对象的 GetGlobalData方法时出现了非法访问，其中代码如下：

在执行拷贝的按钮单击响应事件中：
COleDataSource * pSource = SaveText(); //SavtText为自己写的程序，在下面
if(pSource)
{
pSource->SetClipboard();
}

在执行粘贴的按钮单击响应事件中：
COleDataObject dataObject;
VERIFY(dataObject.AttachClipboard); //从剪贴板得到
DoPasteText(&dataObject); //DoPasteText为自己写的程序，在下面

两个自己写的函数如下：SaveText , DoPasteText

//从m_cSource编辑框控件得到字符串，从字符串的内容创建数据来源对象。
//构造一个COldDataSource对象，然后，将其字符串内容拷贝到全局内存中。
//最后，调用CacheGlobalData来存储在数据来源对象中的HGLOBAL句柄。
COleDataSource * COLEPasteDlg::SaveText()
{
CString strSource;
m_cSource.GetWindowText(strSource);
if(!strSource.IsEmpty()) //if the source string is not empty.
{
COleDataSource * pSource = new COleDataSource();
int nTextSize = strSource.GetLength()-1;
HGLOBAL hText = ::GlobalAlloc(GMEM_SHARE,nTextSize);
LPSTR pText =(LPSTR)::GlobalLock(hText);
ASSERT(pText);
strcpy(pText ,strSource);
::GlobalUnlock(hText);
/*
STGMEDIUM stg;
FORMATETC fmt;
SETFORMATETC(fmt, CF_TEXT, DVASPECT_CONTENT,NULL,TYMED_HGLOBAL,1);
stg.hGlobal = hText;
pSource->CacheData(CF_TEXT,&stg,&fmt);
*/
FORMATETC fmt;
SETFORMATETC(fmt, CF_TEXT, DVASPECT_CONTENT,NULL,TYMED_HGLOBAL,1);
pSource->CacheGlobalData(CF_TEXT, hText,&fmt);
return pSource;
}
return NULL;
}

//从数据对象中填充 strTarget，然后填充到编辑框控件m_cTarget中
BOOL COLEPasteDlg::DoPasteText(COleDataObject *pDataObject)
{
FORMATETC fmt;
SETFORMATETC(fmt, CF_TEXT, DVASPECT_CONTENT,NULL,TYMED_HGLOBAL,1);
//--------------------------------------------Error Occur---------
//下面这一行出现了错误，我跟踪发现是对象的GetData函数出现了错误
//（GetGlobalData在内部实现时调用了GetData函数）
HGLOBAL hText = pDataObject->GetGlobalData(CF_TEXT,&fmt);
//--------------------------------------------Error End---------
ASSERT(hText != NULL);
CString strTarget= (LPSTR)::GlobalLock(hText);
m_cTarget.SetWindowText(strTarget);
::GlobalUnlock(hText);

return TRUE;
}

[masterz]

How to place text on the clipboard
CString source;
//put your text in source
if(OpenClipboard())
{
HGLOBAL clipbuffer;
char * buffer;
EmptyClipboard();
clipbuffer = GlobalAlloc(GMEM_DDESHARE, source.GetLength()+1);
buffer = (char*)GlobalLock(clipbuffer);
strcpy(buffer, LPCSTR(source));
GlobalUnlock(clipbuffer);
SetClipboardData(CF_TEXT,clipbuffer);
CloseClipboard();
}
How to get text off of the clipboard
char * buffer;
if(OpenClipboard())
{
buffer = (char*)GetClipboardData(CF_TEXT);
//do something with buffer here
//before it goes out of scope
}
CloseClipboard();

[masterz]

int nTextSize = strSource.GetLength()-1;// this is not correct. your buffter can not hold the whole string because its length is less than the string length.

[tpProgramer]

thanks for masterz' first help, but I want use the OLE Clipboard，because later I'll use it to copy and cut custom format.

I'll test the code following your advice.

[tpProgramer]

yes! very Good!

if I change the code:

int nTextSize = strSource.GetLength() + 1;
//not GetLength() or GetLength()-1!!

everything is Ok!

thanks for masterz's help !