请教一个Mfc窗口显示的问题

[IT保安]

void CTextView::OnDraw(CDC* pDC) //响应wm_paint消息
{
	CTextDoc* pDoc = GetDocument();
	ASSERT_VALID(pDoc);
	// TODO: add draw code for native data here
	m_str = CString("我是写在OnDraw函数之中");
	HDC hdc;
	PAINTSTRUCT ps;
	hdc = ::BeginPaint(m_hWnd,&ps);
	::TextOut(hdc,0,45,m_str,strlen(m_str));
	::EndPaint(m_hWnd,&ps);
//	pDC->TextOut(0,0,m_str);

用全局函数就不显示字符串啊，只有当我用pDC指针调用textout才能显示出字符串，请问为什么呢？

[赵4老师]

m_str是什么类型？能对其strlen吗？ CString::GetLength int GetLength( ) const; Return Value A count of the bytes in the string. Remarks Call this member function to get a count of the bytes in this CString object. The count does not include a null terminator. For multibyte character sets (MBCS), GetLength counts each 8-bit character; that is, a lead and trail byte in one multibyte character are counted as two bytes. Example The following example demonstrates the use of CString::GetLength. // example for CString::GetLength CString s( "abcdef" ); ASSERT( s.GetLength() == 6 ); CString Overview | Class Members | Hierarchy Chart See Also CString::IsEmpty

[孤影品茗]

你有没有看看，用全局TextOut的时候，屏幕左上角的位置有没有 strlen是系统函数，可以对CString使用，编译器会自动做转换，没问题的

[席戛戛]

strlen(m_str)) 返回值是什么？

[赵4老师]

m_str如果是Unicode编码的CString，能对其用strlen才怪！