using bitmap as logo in diaglog-based app
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i can get the code to compile just fine but when i go to launch my application i get an assertion error, i narrowed down the block of code that might be causing it but i also think i am not correctly writing the code to display the bitmap. this block of code in my OnInitDialog function is where i get the problem from i think. m_st1.GetClientRect( &rectStaticClient ); rectStaticClient.NormalizeRect(); m_size.cx=rectStaticClient.Size().cx; m_size.cy=rectStaticClient.Size().cy; m_size.cx = rectStaticClient.Width(); m_size.cy = rectStaticClient.Height(); m_st1.ClientToScreen( &rectStaticClient ); ScreenToClient( &rectStaticClient); m_pt.x = rectStaticClient.left; m_pt.y = rectStaticClient.top; GetObject( m_hBmpNew , sizeof(BITMAP), &m_bmInfo ); VERIFY(m_hBmpOld = (HBITMAP)SelectObject(m_dcMem, m_hBmpNew ) ); offsetx= m_pt.x; offsety=m_pt.y; InvalidateRect(&rectStaticClient); not really messed with graphics coding much before, if soemone could help me out with whats possibly going on i would really appreciate it.
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i can get the code to compile just fine but when i go to launch my application i get an assertion error, i narrowed down the block of code that might be causing it but i also think i am not correctly writing the code to display the bitmap. this block of code in my OnInitDialog function is where i get the problem from i think. m_st1.GetClientRect( &rectStaticClient ); rectStaticClient.NormalizeRect(); m_size.cx=rectStaticClient.Size().cx; m_size.cy=rectStaticClient.Size().cy; m_size.cx = rectStaticClient.Width(); m_size.cy = rectStaticClient.Height(); m_st1.ClientToScreen( &rectStaticClient ); ScreenToClient( &rectStaticClient); m_pt.x = rectStaticClient.left; m_pt.y = rectStaticClient.top; GetObject( m_hBmpNew , sizeof(BITMAP), &m_bmInfo ); VERIFY(m_hBmpOld = (HBITMAP)SelectObject(m_dcMem, m_hBmpNew ) ); offsetx= m_pt.x; offsety=m_pt.y; InvalidateRect(&rectStaticClient); not really messed with graphics coding much before, if soemone could help me out with whats possibly going on i would really appreciate it.
The assert comes from the previous selected bitmap in your memory DC - 'm_hBmpOld' is null. To display a bitmap you have to paint it OnPaint() not to select it to an DC (DisplayContext).
HDC mdc; HGDIOBJ obmp; BITMAP bmi; if(m_hbmp && GetObject(m_hbmp,sizeof(bmi),&bmi)) { mdc = CreateCompatibleDC(hdc); obmp = SelectObject(mdc,m_hbmp); BitBlt(hdc,offsetx,offsety,bmi.biWidth,bmi.biHeight,mdc,0,0,SRCCOPY); SelectObject(mdc,obmp); DeleteDC(mdc); } -
The assert comes from the previous selected bitmap in your memory DC - 'm_hBmpOld' is null. To display a bitmap you have to paint it OnPaint() not to select it to an DC (DisplayContext).
HDC mdc; HGDIOBJ obmp; BITMAP bmi; if(m_hbmp && GetObject(m_hbmp,sizeof(bmi),&bmi)) { mdc = CreateCompatibleDC(hdc); obmp = SelectObject(mdc,m_hbmp); BitBlt(hdc,offsetx,offsety,bmi.biWidth,bmi.biHeight,mdc,0,0,SRCCOPY); SelectObject(mdc,obmp); DeleteDC(mdc); }tried using the code and sayign hdc is undeclared and when i make it a hdc variable it says oen fo them was used without being initialized. how i set up my dialog was i made a picture control and from there not quite sure exactly what to do, the code you gave by its self wont just display my image as i am sure more code is needed but i get multiple assertions when i load my app and if i ignore them it loads but no image loaded. this is my code so far(most commented out though) that would do the image loading, but i get multiple assertions. afx_msg BOOL CPLoader::OnInitDialog() { /*CClientDC dc(this); m_dcMem.CreateCompatibleDC(&dc); m_hbmp = (HBITMAP) LoadImage( AfxGetInstanceHandle(), "plogo.bmp", IMAGE_BITMAP, 300, 65, LR_LOADFROMFILE); m_st1.SetBitmap(m_hbmp); if( m_hBmpNew == NULL ) { AfxMessageBox("Failed to Load Image"); } else { m_st1.GetClientRect( &rectStaticClient ); rectStaticClient.NormalizeRect(); m_size.cx=rectStaticClient.Size().cx; m_size.cy=rectStaticClient.Size().cy; m_size.cx = rectStaticClient.Width(); m_size.cy = rectStaticClient.Height(); m_st1.ClientToScreen( &rectStaticClient ); ScreenToClient( &rectStaticClient); m_pt.x = rectStaticClient.left; m_pt.y = rectStaticClient.top; GetObject( m_hBmpNew , sizeof(BITMAP), &m_bmInfo ); //VERIFY(m_hBmpOld = (HBITMAP)SelectObject(m_dcMem, m_hBmpNew ) ); offsetx= m_pt.x; offsety=m_pt.y; InvalidateRect(&rectStaticClient); }*/ return true; } afx_msg void CPLoader::OnPaint() { HDC mdc, hdc; HGDIOBJ obmp; BITMAP bmi; if(m_hbmp && GetObject(m_hbmp,sizeof(bmi),&bmi)) { mdc = CreateCompatibleDC(hdc); obmp = SelectObject(mdc,m_hbmp); BitBlt(hdc,offsetx,offsety,bmi.bmWidth,bmi.bmHeight,mdc,0,0,SRCCOPY); SelectObject(mdc,obmp); DeleteDC(mdc); } /*if(IsIconic()) { CPaintDC dc(this); SendMessage(WM_ICONERASEBKGND, (WPARAM) dc.GetSafeHdc(), 0); int cxIcon = GetSystemMetrics(SM_CXICON); int cyIcon = GetSystemMetrics(SM_CYICON); CRect rect; GetClientRect(&rect); int x = (rect.Width() - cxIcon + 1)/2; int y = (rect.Height() - cyIcon +1)/2; dc.DrawIcon(x, y, m_hIcon); } else { CPaintDC dc(this); dc.BitBlt(offsetx, offsety, m_size.cx, m_size.cy, &m_dcMem, sourcex, sourcey, SRCCOPY); CDialog::OnPaint(); }*/ } this is based off of an article i re
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tried using the code and sayign hdc is undeclared and when i make it a hdc variable it says oen fo them was used without being initialized. how i set up my dialog was i made a picture control and from there not quite sure exactly what to do, the code you gave by its self wont just display my image as i am sure more code is needed but i get multiple assertions when i load my app and if i ignore them it loads but no image loaded. this is my code so far(most commented out though) that would do the image loading, but i get multiple assertions. afx_msg BOOL CPLoader::OnInitDialog() { /*CClientDC dc(this); m_dcMem.CreateCompatibleDC(&dc); m_hbmp = (HBITMAP) LoadImage( AfxGetInstanceHandle(), "plogo.bmp", IMAGE_BITMAP, 300, 65, LR_LOADFROMFILE); m_st1.SetBitmap(m_hbmp); if( m_hBmpNew == NULL ) { AfxMessageBox("Failed to Load Image"); } else { m_st1.GetClientRect( &rectStaticClient ); rectStaticClient.NormalizeRect(); m_size.cx=rectStaticClient.Size().cx; m_size.cy=rectStaticClient.Size().cy; m_size.cx = rectStaticClient.Width(); m_size.cy = rectStaticClient.Height(); m_st1.ClientToScreen( &rectStaticClient ); ScreenToClient( &rectStaticClient); m_pt.x = rectStaticClient.left; m_pt.y = rectStaticClient.top; GetObject( m_hBmpNew , sizeof(BITMAP), &m_bmInfo ); //VERIFY(m_hBmpOld = (HBITMAP)SelectObject(m_dcMem, m_hBmpNew ) ); offsetx= m_pt.x; offsety=m_pt.y; InvalidateRect(&rectStaticClient); }*/ return true; } afx_msg void CPLoader::OnPaint() { HDC mdc, hdc; HGDIOBJ obmp; BITMAP bmi; if(m_hbmp && GetObject(m_hbmp,sizeof(bmi),&bmi)) { mdc = CreateCompatibleDC(hdc); obmp = SelectObject(mdc,m_hbmp); BitBlt(hdc,offsetx,offsety,bmi.bmWidth,bmi.bmHeight,mdc,0,0,SRCCOPY); SelectObject(mdc,obmp); DeleteDC(mdc); } /*if(IsIconic()) { CPaintDC dc(this); SendMessage(WM_ICONERASEBKGND, (WPARAM) dc.GetSafeHdc(), 0); int cxIcon = GetSystemMetrics(SM_CXICON); int cyIcon = GetSystemMetrics(SM_CYICON); CRect rect; GetClientRect(&rect); int x = (rect.Width() - cxIcon + 1)/2; int y = (rect.Height() - cyIcon +1)/2; dc.DrawIcon(x, y, m_hIcon); } else { CPaintDC dc(this); dc.BitBlt(offsetx, offsety, m_size.cx, m_size.cy, &m_dcMem, sourcex, sourcey, SRCCOPY); CDialog::OnPaint(); }*/ } this is based off of an article i re
you have to modify your code for using MFC:
CPaintDC dc(this); HDC mdc; HGDIOBJ obmp; BITMAP bmi; if((HBITMAP)m_hbmp && ::GetObject(m_hbmp,sizeof(bmi),&bmi)) { mdc = ::CreateCompatibleDC(dc.m_hDC); obmp = ::SelectObject(mdc,m_hbmp); ::BitBlt(dc.m_hDC,offsetx,offsety,bmi.bmWidth,bmi.bmHeight,mdc,0,0,SRCCOPY); ::SelectObject(mdc,obmp); ::DeleteDC(mdc); }Please mark your code as 'code'.