自画CListCtrl中大图标的问题？？

Question

我要在CListCtrl上创建自画的位图（缩略图），如下代码总是创建出黑色的图，各位帮看看有什么问题？         m_img_list.Create(50,50,ILC_COLOR,20, 20); //创建CImageList

CBitmap * bmp = new CBitmap;//新位图 HDC hdc = ::GetDC(NULL); //得到DC CDC *dc = CDC::FromHandle(hdc);//得到CDC
CDC memdc;//内存DC memdc.CreateCompatibleDC(dc);//创建兼容DC
bmp->CreateCompatibleBitmap(dc,50,50); //创建兼容位图

CBitmap * oldbmp = memdc.SelectObject(bmp);  memdc.SetBkColor(0xFFFFFF);
memdc.FillSolidRect(0,0,50,50,0x0000ff);
memdc.LineTo(100,100); //画线

m_img_list.Add(bmp,RGB(0,255,0)); //加入

m_list_ctrl.SetImageList(&m_img_list,LVSIL_NORMAL); m_list_ctrl.InsertItem(1,"直线",0); memdc.SelectObject(oldbmp);
::ReleaseDC(NULL,hdc);  正确结果应该是有一个画直线的项目， 但现在是一个黑色的框。
  问题出在哪里？

Answer 1

非常感谢 badknife(断刀) 的帮助：不过。。
 
我修改过后还是画出线来，图表只是白色的区域
哪里还有问题？？迷茫以下是修改过后的代码：m_img_list.Create(50,50,ILC_COLOR,20, 20);  BITMAPINFOHEADER bi;
DWORD*  pBits = NULL;
bi.biSize = sizeof(bi);
bi.biPlanes = 1;
bi.biBitCount = 24;
bi.biCompression = BI_RGB;
bi.biSizeImage = 0;
bi.biWidth = 50;
bi.biHeight = 50;
bi.biXPelsPerMeter = 0; 
bi.biYPelsPerMeter = 0; 
bi.biClrUsed = 0; 
bi.biClrImportant = 0;  HBITMAP hBitmap;
HBITMAP hOldBitmap;
HDC hdc = ::GetDC(NULL); //得到DC
CDC *dc = CDC::FromHandle(hdc);//得到CDC
CDC memdc;//内存DC memdc.CreateCompatibleDC(dc); 
hBitmap = CreateDIBSection(hdc,(BITMAPINFO*)&bi, 0, (void**)&pBits,NULL, 0);
hOldBitmap =(HBITMAP)memdc.SelectObject(hBitmap);
memdc.SetBkColor(0xFFFF00);
memdc.FillSolidRect(0,0,50,50,0xff00ff);
memdc.LineTo(100,100); //画线

CBitmap * cmap = new CBitmap;
cmap->FromHandle(hBitmap); m_img_list.Add(cmap,RGB(0,255,0)); //加入
m_list_ctrl.SetImageList(&m_img_list,LVSIL_NORMAL);
m_list_ctrl.InsertItem(0,"直线",0);

memdc.SelectObject(hOldBitmap);
DeleteObject(hBitmap);
::ReleaseDC(NULL,hdc);

Answer 2

非常感谢  badknife(断刀)  的帮助：  
 
不过还是不行。。  
   
我修改过后还是画不出线来，图表只是白色的区域  哪里还有问题？？迷茫  
 
以下是修改过后的代码：  
 
m_img_list.Create(50,50,ILC_COLOR,20,  20);    
 
           BITMAPINFOHEADER  bi;  
           DWORD*    pBits  =  NULL;  
           bi.biSize  =  sizeof(bi);  
           bi.biPlanes  =  1;  
           bi.biBitCount  =  24;  
           bi.biCompression  =  BI_RGB;  
           bi.biSizeImage  =  0;  
           bi.biWidth  =  50;  
           bi.biHeight  =  50;  
           bi.biXPelsPerMeter  =  0;    
           bi.biYPelsPerMeter  =  0;    
           bi.biClrUsed  =  0;    
           bi.biClrImportant  =  0;    
 
           HBITMAP  hBitmap;  
           HBITMAP  hOldBitmap;  
           HDC  hdc  =  ::GetDC(NULL);  //得到DC  
           CDC  *dc  =  CDC::FromHandle(hdc);//得到CDC  
           CDC  memdc;//内存DC  
 
           memdc.CreateCompatibleDC(dc);    
           hBitmap  =  CreateDIBSection(hdc,(BITMAPINFO*)&bi,  0,  (void**)&pBits,NULL,  0);  
           hOldBitmap  =(HBITMAP)memdc.SelectObject(hBitmap);  
           memdc.SetBkColor(0xFFFF00);  
           memdc.FillSolidRect(0,0,50,50,0xff00ff);  
           memdc.LineTo(100,100);  //画线  
             
           CBitmap  *  cmap  =  new  CBitmap;  
           cmap-  >FromHandle(hBitmap);  
 
           m_img_list.Add(cmap,RGB(0,255,0));  //加入              
           m_list_ctrl.SetImageList(&m_img_list,LVSIL_NORMAL);  
           m_list_ctrl.InsertItem(0,  "直线  ",0);              
             
           memdc.SelectObject(hOldBitmap);  
           DeleteObject(hBitmap);  
           ::ReleaseDC(NULL,hdc);

Answer 3

我这里从LISTCTL中派生了一个类
typedef struct
{
UINT nImageID;
char* strText;
}CONTENT_ITEMS,*pCONTENT_ITEMS;
/////////////////////////////////////////////////////////////////////////////
// CContentMenu windowclass CContentMenu : public CListBox
{
// Construction
public:
CContentMenu();// Attributes
public:// Operations
public:
void SetItems(pCONTENT_ITEMS pItems,int nNumItems)
{
m_pContents=pItems;
m_nNumItems=nNumItems;
for(int i=0;i<nNumItems;i++)
AddString("");
}// Overrides
// ClassWizard generated virtual function overrides
//{{AFX_VIRTUAL(CContentMenu)
public:
virtual void DrawItem(LPDRAWITEMSTRUCT lpDrawItemStruct);
virtual void MeasureItem(LPMEASUREITEMSTRUCT lpMeasureItemStruct);
//}}AFX_VIRTUAL// Implementation
public:
virtual ~CContentMenu();
protected:
bool m_bHilight;
bool m_bLBDown;
pCONTENT_ITEMS m_pContents;
int m_nNumItems;
CPoint m_Point;
// Generated message map functions
protected:
//{{AFX_MSG(CContentMenu)
afx_msg void OnLButtonDown(UINT nFlags, CPoint point);
afx_msg void OnLButtonUp(UINT nFlags, CPoint point);
afx_msg void OnMouseMove(UINT nFlags, CPoint point);
afx_msg void OnTimer(UINT nIDEvent);
afx_msg BOOL OnEraseBkgnd(CDC* pDC);
//}}AFX_MSG DECLARE_MESSAGE_MAP()
};
整个自画函数是这样的：
void CContentMenu::DrawItem(LPDRAWITEMSTRUCT lpDIS) 
{
// TODO: Add your code to draw the specified item
CDC*            pDC = CDC::FromHandle(lpDIS->hDC);
    CRect           rcItem(lpDIS->rcItem);
    CRect           rClient(rcItem);
    CRect           rText;
    CPoint          Pt(((rcItem.Width() - 32) /2 ), rcItem.top + 15);
    pCONTENT_ITEMS  pContents    = &m_pContents[lpDIS->itemID];
    HICON           hIcon = AfxGetApp()->LoadIcon(pContents->nImageID);
CDC memDC[4];
CBitmap MyButtonBK[4];

MyButtonBK[0].LoadBitmap(IDB_BUTTON1);
memDC[0].CreateCompatibleDC(pDC);
CBitmap* pOldBmp=memDC[0].SelectObject(&MyButtonBK[0]);

MyButtonBK[1].LoadBitmap(IDB_BUTTON2);
memDC[1].CreateCompatibleDC(pDC);
CBitmap* pOldBmp1=memDC[1].SelectObject(&MyButtonBK[1]); MyButtonBK[2].LoadBitmap(IDB_BUTTON3);
memDC[2].CreateCompatibleDC(pDC);
CBitmap* pOldBmp2=memDC[2].SelectObject(&MyButtonBK[2]); MyButtonBK[3].LoadBitmap(IDB_BUTTON4);
memDC[3].CreateCompatibleDC(pDC);
CBitmap* pOldBmp3=memDC[3].SelectObject(&MyButtonBK[3]);    rClient.DeflateRect(2,5);
rcItem.CopyRect(rClient);
    rText.CopyRect(rClient);
    rText.top += 45;    pDC->SetBkMode(TRANSPARENT);
if (lpDIS->itemAction & ODA_DRAWENTIRE)
    {
        pDC->DrawIcon(Pt, hIcon);
pDC->SetTextColor(RGB(24,255,3));
        pDC->DrawText(pContents->strText, rText, DT_CENTER|DT_WORDBREAK);
    }    if  (m_bLBDown)
    {
        Pt.x += 2;
        Pt.y += 2;
        rcItem.OffsetRect(2,2);
        rText.OffsetRect(2,2);
    } if ((lpDIS->itemState & ODS_SELECTED) &&
(lpDIS->itemAction & (ODA_SELECT | ODA_DRAWENTIRE)))
    {
        if  (m_bHilight)
        {
            pDC->FillSolidRect(rClient,RGB(255,255,255));            if  (m_bLBDown)
                pDC->Draw3dRect(rClient,RGB(3,38,3), 
RGB(36,94,34));
            else
                pDC->Draw3dRect(rClient,GetSysColor(COLOR_BTNHIGHLIGHT),
GetSysColor(COLOR_3DSHADOW));        }
switch(GetCurSel())
{
case 0:
pDC->BitBlt(rcItem.left,rcItem.top,rcItem.right,rcItem.bottom,
&memDC[0],0,0,SRCCOPY);
break;
case 1:
pDC->BitBlt(rcItem.left,rcItem.top,rcItem.right,rcItem.bottom,
&memDC[1],0,0,SRCCOPY);
break;
case 2:
pDC->BitBlt(rcItem.left,rcItem.top,rcItem.right,rcItem.bottom,
&memDC[2],0,0,SRCCOPY);
break;
case 3:
pDC->BitBlt(rcItem.left,rcItem.top,rcItem.right,rcItem.bottom,
&memDC[3],0,0,SRCCOPY);
break;
}
        pDC->DrawIcon(Pt, hIcon);
pDC->SetTextColor(RGB(24,255,3));
        pDC->DrawText(pContents->strText, rText, DT_CENTER|DT_WORDBREAK);
    } if (!(lpDIS->itemState & ODS_SELECTED) &&
(lpDIS->itemAction & ODA_SELECT))
    {
        pDC->FillSolidRect(rClient,RGB(24,255,3));
switch(GetCurSel())
{
case 0:
pDC->BitBlt(rcItem.left,rcItem.top,rcItem.right,rcItem.bottom,
&memDC[0],0,0,SRCCOPY);
break;
case 1:
pDC->BitBlt(rcItem.left,rcItem.top,rcItem.right,rcItem.bottom,
&memDC[1],0,0,SRCCOPY);
break;
case 2:
pDC->BitBlt(rcItem.left,rcItem.top,rcItem.right,rcItem.bottom,
&memDC[2],0,0,SRCCOPY);
break;
case 3:
pDC->BitBlt(rcItem.left,rcItem.top,rcItem.right,rcItem.bottom,
&memDC[3],0,0,SRCCOPY);
break;
}
pDC->DrawIcon(Pt, hIcon);
pDC->SetTextColor(RGB(24,255,3));
        pDC->DrawText(pContents->strText, rText, DT_CENTER|DT_WORDBREAK);
    }}

Answer 4

CBitmap 是动态创建的，不能调资源。