开帖急问 SendDlgItemMessage（）控制slider没有任何效果

Question

在VC（非MFC）中控制slider的位置，但是不知道为什么却没有任何效果但是 操作 如下： 
先设置slider的最大值和最小值 
LenSlidertemp1=SendDlgItemMessage(hwndCtl, IDC_SLIDER1,TBM_SETRANGEMAX , TRUE, SliderMax); 
LenSlidertemp2=SendDlgItemMessage(hwndCtl, IDC_SLIDER1,TBM_SETRANGEMIN , TRUE, SliderMin); 不知道为什么 这里temp1 temp2返回值都是0 然后为了检验一下 设置slider到中间： dwPercent = SendDlgItemMessage(hwndCtl, IDC_SLIDER1, TBM_GETPOS, 0, 0); RETAILMSG(1,(L"\nIDC_Start = %d\n",dwPercent)); 
SendDlgItemMessage( 
hwndCtl, 
IDC_SLIDER1, 
TBM_SETPOS, 
TRUE, 
m_dwCurrPercent  //直接设置为50 
); dwPercent = SendDlgItemMessage(hwndCtl, IDC_SLIDER1, TBM_GETPOS, 0, 0); RETAILMSG(1,(L"\nIDC_Start = %d\n",dwPercent)); dwPercent = SendDlgItemMessage(hwndCtl, IDC_SLIDER1, TBM_GETTHUMBLENGTH, 0, 0); RETAILMSG(1,(L"\nIDC_Start = %d\n",dwPercent)); dwPercent = SendDlgItemMessage(hwndCtl, IDC_SLIDER1, TBM_GETRANGEMAX ,0, 0); RETAILMSG(1,(L"\nIDC_Start = %d\n",dwPercent)); 
dwPercent = SendDlgItemMessage(hwndCtl, IDC_SLIDER1, TBM_GETRANGEMIN , 0, 0); RETAILMSG(1,(L"\nIDC_Start = %d\n",dwPercent)); 
输出全部是0 
不知道为什么没有效果

Answer 1

SendDlgItemMessage第一个参数应该是对话框（控件父窗口）的句柄，看你的命名似乎是控件自身的句柄，那么直接用SendMessage好了。

Answer 2

这个控件是在 About对话框中的  而这对话框的回调函数About：
INT_PTR CALLBACK About(HWND hDlg, UINT message, WPARAM wParam, LPARAM lParam)
{
CBaseDlg *vRecDlg;    switch (message)
    {
        case WM_INITDIALOG:
            RECT rectChild, rectParent;
            int DlgWidth, DlgHeight; // dialog width and height in pixel units
            int NewPosX, NewPosY;
    vRecDlg= new CBaseDlg();
    if(vRecDlg ==NULL)
    {
             RETAILMSG(1,(L"vRecDlg requirment error\n"));
     return 0;
         }
    vRecDlg->OnInitDialog(hDlg);    //这里先设置slider的最大值和最小值 
            // trying to center the About dialog
            if (GetWindowRect(hDlg, &rectChild)) 
            {
                GetClientRect(GetParent(hDlg), &rectParent);
                DlgWidth = rectChild.right - rectChild.left;
                DlgHeight = rectChild.bottom - rectChild.top ;
                NewPosX = (rectParent.right - rectParent.left - DlgWidth) / 2;
                NewPosY = (rectParent.bottom - rectParent.top - DlgHeight) / 2;

                // if the About box is larger than the physical screen 
                if (NewPosX < 0) NewPosX = 0;
                if (NewPosY < 0) NewPosY = 0;
          SetWindowPos(hDlg, 0, rectChild.left, rectChild.top,
wid, hei, SWP_NOZORDER | SWP_NOZORDER);
            }
            return (INT_PTR)TRUE;        case WM_COMMAND:
            if ((LOWORD(wParam) == IDOK) || (LOWORD(wParam) == IDCANCEL))
            {
                EndDialog(hDlg, LOWORD(wParam));
CommandBar_Destroy(g_hWndCommandBar);
PostQuitMessage(0);
                return TRUE;
            }else
vRecDlg->OnCommand(HIWORD(wParam), LOWORD(wParam), (HWND)lParam);//这里操作slider的位置
            break;        case WM_CLOSE:
            EndDialog(hDlg, message);
CommandBar_Destroy(g_hWndCommandBar);
PostQuitMessage(0);
            return TRUE;    }
    return (INT_PTR)FALSE;
}关于Oncommand()函数和ini函数：BOOL CBaseDlg::OnCommand(WORD wNotifyCode, WORD wID, HWND hwndCtl)
{
BOOL brc = TRUE;
HWND    phWnd = NULL;
DWORD m_dwCurrPercent=50;
DWORD dwPercent;
switch(wID)
{
case IDC_Start:
RETAILMSG(1,(L"\nIDC_Start\n"));
SetTimer(hwndCtl,1,1000,NULL); dwPercent = SendDlgItemMessage(hwndCtl, IDC_SLIDER1, TBM_GETPOS, 0, 0); RETAILMSG(1,(L"\nIDC_Start = %d\n",dwPercent));
SendDlgItemMessage(
hwndCtl, 
IDC_SLIDER1,
TBM_SETPOS,
TRUE,
m_dwCurrPercent
);  dwPercent = SendDlgItemMessage(hwndCtl, IDC_SLIDER1, TBM_GETPOS, 0, 0);

RETAILMSG(1,(L"\nIDC_Start = %d\n",dwPercent)); dwPercent = SendDlgItemMessage(hwndCtl, IDC_SLIDER1, TBM_GETTHUMBLENGTH, 0, 0); RETAILMSG(1,(L"\nIDC_Start = %d\n",dwPercent)); dwPercent = SendDlgItemMessage(hwndCtl, IDC_SLIDER1, TBM_GETRANGEMAX ,0, 0); RETAILMSG(1,(L"\nIDC_Start = %d\n",dwPercent));
dwPercent = SendDlgItemMessage(hwndCtl, IDC_SLIDER1, TBM_GETRANGEMIN , 0, 0); RETAILMSG(1,(L"\nIDC_Start = %d\n",dwPercent));
// OnTimer(1);
startAudioRec();
break;
case IDC_Stop:
RETAILMSG(1,(L"\nIDC_Stop\n"));
KillTimer(hwndCtl,1);
MSG msg;
// buttonStop.SetState(1);
msg.message = WM_USER+1;
RETAILMSG(1,(L"\nIDC_Stop1\n"));
PostMessage(hwndCtl,msg.message,0,0);
RETAILMSG(1,(L"\nIDC_Stop2\n"));
slider_count = 0;
break;
case IDC_Play:
RETAILMSG(1,(L"\nIDC_Play\n"));
break;
default:
break;
}
return TRUE;}BOOL CBaseDlg::OnInitDialog(HWND hwndCtl)
{
DWORD LenSlidertemp;
DWORD SliderMax=100;
DWORD SliderMin=0;
HWND shwnd;
shwnd=GetDlgItem(hwndCtl,IDC_SLIDER1);
if(shwnd==NULL)
RETAILMSG(1,(L"shwnd is null"));
LenSlidertemp=SendDlgItemMessage(shwnd, IDC_SLIDER1,TBM_SETRANGEMAX , FALSE, SliderMax); LenSlidertemp=SendDlgItemMessage(shwnd, IDC_SLIDER1,TBM_SETRANGEMIN , FALSE, SliderMin); return TRUE;
}

Answer 3

其中ini函数中 有这么一行 我是测试用的BOOL CBaseDlg::OnInitDialog(HWND hwndCtl) 
{ 
DWORD LenSlidertemp; 
DWORD SliderMax=100; 
DWORD SliderMin=0; 
HWND shwnd; 
shwnd=GetDlgItem(hwndCtl,IDC_SLIDER1); //这个shwnd原来是没有的 直接就是hwndCtl 但是也不行的
if(shwnd==NULL) 
RETAILMSG(1,(L"shwnd is null")); 
LenSlidertemp=SendDlgItemMessage(shwnd, IDC_SLIDER1,TBM_SETRANGEMAX , FALSE, SliderMax); LenSlidertemp=SendDlgItemMessage(shwnd, IDC_SLIDER1,TBM_SETRANGEMIN , FALSE, SliderMin); return TRUE; 
}

Answer 4

直接用函数好了阿
CWnd *pWnd = GetDlgItem(IDC_SLIDER1);
if(pWnd && pWnd->m_hWnd)
  ((CSliderCtrl*)pWnd)->SetRange(SliderMin,SliderMax);如果用消息
::SendMessage(pWnd->m_hWnd, TBM_SETRANGEMIN, FALSE, (LPARAM) SliderMin);
::SendMessage(pWnd->m_hWnd, TBM_SETRANGEMIN, TRUE, (LPARAM) SliderMax);参看 DDV_MinMaxSlider 原形void AFXAPI DDV_MinMaxSlider(CDataExchange* pDX, DWORD value, DWORD minVal, DWORD maxVal)
{
  ASSERT(minVal <= maxVal);
  if (!pDX->m_bSaveAndValidate)
  {
    if (minVal > value || maxVal < value)
    {
     #ifdef _DEBUG
      int nIDC = GetWindowLong(pDX->m_hWndLastControl, GWL_ID);
      TRACE1("Warning: initial dialog data is out of range in control ID %d.\n", nIDC);
     #endif
      return;     // don't stop now
    }
  }
  ::SendMessage(pDX->m_hWndLastControl, TBM_SETRANGEMIN, FALSE, (LPARAM) minVal);
  ::SendMessage(pDX->m_hWndLastControl, TBM_SETRANGEMIN, TRUE, (LPARAM) maxVal);
}

Answer 5

CSliderCtrl 是MFC的 不能用to zgl7903 你的用sendmessage不行 CWnd *pWnd = GetDlgItem(IDC_SLIDER1); 
CWND好像在这里不能识别
我是用：
HWND shwnd; 
shwnd=GetDlgItem(hwndCtl,IDC_SLIDER1); //这里成功  ::SendMessage(hwndCtl, TBM_SETRANGEMIN, FALSE, (LPARAM) minVal); 
  ::SendMessage(hwndCtl, TBM_SETRANGEMIN, TRUE, (LPARAM) maxVal);不能我怀疑  hwndCtl 出问题 但是不肯定 因为shwnd=GetDlgItem(hwndCtl,IDC_SLIDER1); 返回了啊所以不明白为什么了
谢谢