MFC完成图片查看器的功能

2024-06-18 07:42| 来源: 网络整理| 查看: 265

MFC完成图片查看器的功能预期目标：

1.打开同类型的位图，文件按顺序排列时可顺序打开下一张图像； 2.用鼠标滚轮完成图像的放大及缩小，且以鼠标所指的像素点为固定像素点； 3.显示图像的绝对像素坐标和相对像素坐标，并且显示图像的放大比例。

需要注意的点：

1.在放大的时候，会遇到图像上、下、左、右侧超出显示控件的情况，因此在放大的时候，需要判断图像边界位置。 2.在放大及缩小的时候要保证图像长宽同比变换，即保证图像不失真。 3.在找出图像绝对像素坐标和相对像素坐标时，要注意比例转换。 4.开始楼主敲得代码，在缩放图像时，总是出现闪屏的现象，后来才发现原因，不能直接在控件里放置图像，需要在缓存一次，就解决闪屏现象。

效果图如下：

缩放效果

话不多说，直接上代码！原创不易，转载请注明出处，谢谢~ 水平有限，欢迎指正交流~~ void CImageViewDlg::OnSize(UINT nType, int cx, int cy) { if (m_listRect.GetCount() > 0) { CRect dlgNow; GetWindowRect(&dlgNow); POSITION pos = m_listRect.GetHeadPosition();//第一个保存的是对话框的Rect CRect dlgSaved; dlgSaved = m_listRect.GetNext(pos); ScreenToClient(dlgNow); float x = dlgNow.Width() * 1.0 / dlgSaved.Width();//根据当前和之前保存的对话框的宽高求比例 float y = dlgNow.Height() *1.0 / dlgSaved.Height(); ClientToScreen(dlgNow); CRect childSaved; CWnd* pWnd = GetWindow(GW_CHILD); while (pWnd) { childSaved = m_listRect.GetNext(pos);//依次获取子窗体的Rect childSaved.left = dlgNow.left + (childSaved.left - dlgSaved.left)*x;//根据比例调整控件上下左右距离对话框的距离 childSaved.right = dlgNow.right + (childSaved.right - dlgSaved.right)*x; childSaved.top = dlgNow.top + (childSaved.top - dlgSaved.top)*y; childSaved.bottom = dlgNow.bottom + (childSaved.bottom - dlgSaved.bottom)*y; ScreenToClient(childSaved); pWnd->MoveWindow(childSaved); pWnd = pWnd->GetNextWindow(); } CWnd *pwnd = GetDlgItem(IDC_Picture); pwnd->GetClientRect(&picRect); CDC *pDC = pwnd->GetDC(); pDC->SetStretchBltMode(COLORONCOLOR); Image.Destroy(); File_Open = Image.Load(FilePath); if (File_Open != 0) { File_Open = 2; return; } RectSize(Image, picRect, curRect, Image_scale); ZoomImage(Image, picRect, curRect, g_iZoom, Image_scale); } }

打开文件。

void CImageViewDlg::OnBnClickedOpenFile() { CString filter = L"所有文件(*.bmp,*.jpg,*.tiff)|*.bmp;*.jpg;*.gif;*.tiff| BMP(*.bmp)|*.bmp|JPG(*.jpg)|*.jpg|GIF(*.gif)|TIFF(*.tiff)|*.tiff"; CFileDialog Ofile(TRUE, NULL, NULL, OFN_HIDEREADONLY, filter, NULL); g_iZoom = 1; g_iRadio = 0.5; if (IDOK == Ofile.DoModal()) { FilePath = Ofile.GetPathName(); CString fEnt = Ofile.GetFileExt(); End_name = fEnt.MakeLower(); File_Folder = FilePath.Left(FilePath.GetLength() - End_name.GetLength() - 2); CString tmp_count = FilePath.Left(FilePath.GetLength() - End_name.GetLength() - 1); tmp_count = tmp_count.Right(1); count = _ttoi(tmp_count); CWnd* pWnd = GetDlgItem(IDC_Picture); CDC* pDC = pWnd->GetDC(); HDC hDC = pDC->m_hDC; pWnd->GetClientRect(&picRect); Image.Destroy(); Image.Load(FilePath); Image_Rat = (float)Image.GetWidth() / (float)Image.GetHeight(); RectSize(Image, picRect, curRect, Image_scale); ::SetStretchBltMode(hDC, HALFTONE); ::SetBrushOrgEx(hDC, 0, 0, NULL); ZoomImage(Image, picRect, curRect, g_iZoom, Image_scale); SetDlgItemText(IDC_Text1, FilePath); ReleaseDC(pDC); } // TODO: 在此添加控件通知处理程序代码 } void CImageViewDlg::OnBnClickedNextFile() { CString filter = L"所有文件(*.bmp,*.jpg,*.tiff)|*.bmp;*.jpg;*.gif;*.tiff| BMP(*.bmp)|*.bmp|JPG(*.jpg)|*.jpg|GIF(*.gif)|TIFF(*.tiff)|*.tiff"; CFileDialog Ofile(TRUE, NULL, NULL, OFN_HIDEREADONLY, filter, NULL); CString tmp_Path, tmp_count; g_iZoom = 1; g_iRadio = 0.5; count++; tmp_count.Format(_T("%01d."), count); FilePath = File_Folder + tmp_count + End_name; CWnd* pWnd; pWnd = GetDlgItem(IDC_Picture); CDC* pDC = pWnd->GetDC(); HDC hDC = pDC->m_hDC; pWnd->GetClientRect(&picRect); Image.Destroy(); File_Open = Image.Load(FilePath); if (File_Open != 0) { count--; tmp_count.Format(_T("%01d."), count); FilePath = File_Folder + tmp_count + End_name; File_Open = Image.Load(FilePath); File_Open = 2; return; } Image_Rat = (float)Image.GetWidth() / (float)Image.GetHeight(); RectSize(Image, picRect, curRect, Image_scale); ::SetStretchBltMode(hDC, HALFTONE); ::SetBrushOrgEx(hDC, 0, 0, NULL); ZoomImage(Image, picRect, curRect, g_iZoom, Image_scale); SetDlgItemText(IDC_Text1, FilePath); ReleaseDC(pDC); // TODO: 在此添加控件通知处理程序代码 }

缩放到边缘时，避免图像移出显示窗口。

void CImageViewDlg::RectSize(CImage &inputImage, CRect &inputRect, CRect &outputRect, float &imput_scale) { float in_x, in_y; in_x = inputRect.Width(); in_y = inputRect.Height(); float rows, cols; rows = inputImage.GetHeight(); cols = inputImage.GetWidth(); float rat = cols / rows; if (rows > in_y && cols in_y && cols > in_x) { if ((rows / in_y) >= (cols / in_x)) { imput_scale = rows / in_y; outputRect.left = (in_x - (in_y * rat)) / 2; outputRect.right = outputRect.left + (in_y * rat); outputRect.top = 0; outputRect.bottom = in_y; } else if ((rows / in_y)

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MFC完成图片查看器的功能

MFC完成图片查看器的功能

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