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过年回家，走之前留一个用GDI+实现的略缩图控件

时间：2022-12-13 18:02:33浏览次数：40  
标签：控件 CompareNoCase 缩图 TEXT CListImageCtrl strExt GDI VectorImageNames THUMBNAIL


这是一个加载文件夹图片略缩图的控件，支持多种图片格式~~用法也比较简单


过年回家，走之前留一个用GDI+实现的略缩图控件_file



（1）、源代码 


//头文件ListImageCtrl.h  
   
#pragma once
  
#include <vector>
  

  
//note:need GDI+
  

  
// ListImageCtrl.h : header file
  

  
class CListImageCtrl : public CListCtrl
  
{
  
// Construction
  
public:
  
CListImageCtrl();
  

  
// Attributes
  
public:
  
void CreateColumn();
  
//
  
BOOL  GetImageFileNames();// gather the image file names
  
void  DrawThumbnails();// draw the thumbnails in list control
  
void  Load();         //start load files
  
void Clear();   //clear list
  

  
// Operations
  
public:
  
CStringm_strImageDir;
  
CImageListm_ImageListThumb;// image list holding the thumbnails
  
std::vector<CString> m_VectorImageNames;// vector holding the image names
  
intm_nSelectedItem;
  
BOOL  m_bHorz;
  

  
// Overrides
  
// ClassWizard generated virtual function overrides
  
//{{AFX_VIRTUAL(CListImageCtrl)
  
//}}AFX_VIRTUAL
  

  
// Implementation
  
public:
  
virtual ~CListImageCtrl();
  

  
// Generated message map functions
  
protected:
  
//{{AFX_MSG(CListImageCtrl)
  
afx_msg void OnDropFiles(HDROP hDropInfo);
  
//}}AFX_MSG
  

  
DECLARE_MESSAGE_MAP()
  
};
  

  
  
  
// ListImageCtrl.cpp : implementation file
  
//
  

  
#include "stdafx.h"
  
#include "Medical.h"
  
#include "ListImageCtrl.h"
  

  
#define THUMBNAIL_WIDTH  90
  
#define THUMBNAIL_HEIGHT 90
  

  
void DoEvents(void);
  

  
/
  
// CListImageCtrl
  

  
CListImageCtrl::CListImageCtrl()
  
{
  
m_strImageDir = _T("");
  
m_bHorz = FALSE;
  
}
  

  
CListImageCtrl::~CListImageCtrl()
  
{
  
}
  

  

  
BEGIN_MESSAGE_MAP(CListImageCtrl, CListCtrl)
  
//{{AFX_MSG_MAP(CListImageCtrl)
  
ON_WM_DROPFILES()
  
//}}AFX_MSG_MAP
  
END_MESSAGE_MAP()
  

  
/
  
// CListImageCtrl message handlers
  

  
// This funtion is used to load the Window dropped files into the listview
  

  
void CListImageCtrl::OnDropFiles(HDROP hDropInfo) 
  
{
  
WORD wNumFilesDropped = DragQueryFile(hDropInfo, -1, NULL, 0);
  

  
CString firstFile(_T(""));
  
int kk=0;
  
int tTot=(int)wNumFilesDropped;
  

  
// show hour glass cursor
  
BeginWaitCursor();
  

  
for (WORD x = 0 ; x < wNumFilesDropped; x++) 
  
{
  
kk++;
  
// Get the number of bytes required by the file's full pathname
  
WORD wPathnameSize = DragQueryFile(hDropInfo, x, NULL, 0);
  
TRACE1("wPathnameSize=%d,\n",wPathnameSize);
  

  
// Allocate memory to contain full pathname & zero byte
  
wPathnameSize +=1;
  
TCHAR * npszFile = (TCHAR *) LocalAlloc(LPTR, sizeof(TCHAR)*wPathnameSize);  //注意分配的内存大小
  

  
// If not enough memory, skip this one
  
if (npszFile == NULL) continue;
  
DragQueryFile(hDropInfo, x, npszFile, wPathnameSize);
  

  
if (firstFile=="") 
  
firstFile=npszFile;
  

  
CString strExt;
  
CString nFileText;
  
CString pItemText=npszFile;
  

  
TRACE1("%s\n",pItemText);
  

  
int i=pItemText.ReverseFind('\\');
  
nFileText = pItemText.Mid(i+1); 
  
m_strImageDir = pItemText.Left(i+1);
  

  
strExt = pItemText.Right(3);
  
TRACE1("strExt=%s\n",strExt);
  

  
if ( (strExt.CompareNoCase( TEXT("bmp") ) == 0) ||
  
(strExt.CompareNoCase( TEXT("jpg") ) == 0) ||
  
(strExt.CompareNoCase( TEXT("gif") ) == 0) ||
  
(strExt.CompareNoCase( TEXT("tif") ) == 0) ||
  
(strExt.CompareNoCase( TEXT("png") ) == 0) )
  
{
  
// save the image file name, not the path
  
m_VectorImageNames.push_back(nFileText);  
  
}
  

  
// clean up
  
LocalFree(npszFile);
  
}
  

  
// Free the memory block containing the dropped-file information
  
DragFinish(hDropInfo);
  

  
if(!m_VectorImageNames.empty())
  
DrawThumbnails();
  

  
SetFocus();
  
SetItemState(0, LVIS_SELECTED |    LVS_ICON | LVS_AUTOARRANGE, LVIS_SELECTED | LVIS_FOCUSED | LVIS_ACTIVATING); 
    
EndWaitCursor();
  

  
CListCtrl::OnDropFiles(hDropInfo);
  
}
  

  

  
void CListImageCtrl::CreateColumn()
  
{
  
InsertColumn(0,_T("Filename"),LVCFMT_LEFT,125,-1);
  
InsertColumn(1,_T("Path"),LVCFMT_LEFT,125,-1);
  
InsertColumn(2,_T("Size"),LVCFMT_LEFT,75,-1);
  

  
HIMAGELIST hScreens = ImageList_Create(THUMBNAIL_WIDTH, THUMBNAIL_HEIGHT, ILC_COLOR32 /*| ILC_MASK*/ , 0, 1);
  
m_ImageListThumb.Attach(hScreens);
  
m_nSelectedItem = 0;
  

  
// load the starting bitmap ("Loading..." and "Corrupt file")
  
//  CBitmap dummy;
  
//  dummy.LoadBitmap(IDB_BITMAP1);
  
//  m_ImageListThumb.Add(&dummy, RGB(0, 0, 0));
  

  
SetImageList(&m_ImageListThumb, LVSIL_NORMAL);
  
SetImageList(&m_ImageListThumb, LVSIL_SMALL);
  

  
}
  

  
// this function is used to enable the system messages
  
// this is mainly used to display the multiple images dropped on the list control
  

  
void DoEvents(void)
  
{
  
    MSG Symsg;
  
    
  
    while(PeekMessage(&Symsg,NULL,0,0,PM_REMOVE))
  
    {
  
    TranslateMessage(&Symsg);
  
    DispatchMessage(&Symsg);
  
    }
  
}
  

  
BOOL  CListImageCtrl::GetImageFileNames()
  
{
  
CStringstrExt;
  
CStringstrName;
  
CStringstrPattern;
  
BOOLbRC = TRUE;
  

  
HANDLEhFind = NULL;
  
WIN32_FIND_DATAFindFileData;
  
std::vector<CString>VectorImageNames;
  

  
if ( m_strImageDir[m_strImageDir.GetLength() - 1] == TCHAR('\\') )
  
strPattern.Format( TEXT("%s*.*"), m_strImageDir );
  
else
  
strPattern.Format( TEXT("%s\\*.*"), m_strImageDir );
  

  
hFind = ::FindFirstFile(strPattern, &FindFileData);// strat search
  
if (hFind == INVALID_HANDLE_VALUE)
  
{
  
LPVOID  msg;
  
::FormatMessage(FORMAT_MESSAGE_ALLOCATE_BUFFER | FORMAT_MESSAGE_FROM_SYSTEM, 
  
NULL, 
  
GetLastError(), 
  
MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT),
  
(LPTSTR)&msg, 
  
0, 
  
NULL);
  
MessageBox((LPTSTR)msg, CString((LPCSTR)IDS_TITLE), MB_OK|MB_ICONSTOP);
  
::LocalFree(msg);
  
return FALSE;
  
}
  

  
// filter off the system files and directories
  
if (!(FindFileData.dwFileAttributes & FILE_ATTRIBUTE_DIRECTORY)  &&
  
!(FindFileData.dwFileAttributes & FILE_ATTRIBUTE_SYSTEM)     &&
  
!(FindFileData.dwFileAttributes & FILE_ATTRIBUTE_HIDDEN)     &&
  
!(FindFileData.dwFileAttributes & FILE_ATTRIBUTE_TEMPORARY))
  
{  
  
// test file extension
  
strName = FindFileData.cFileName;
  
strExt = strName.Right(3);
  

  
if ( (strExt.CompareNoCase( TEXT("bmp") ) == 0) ||
  
(strExt.CompareNoCase( TEXT("jpg") ) == 0) ||
  
(strExt.CompareNoCase( TEXT("gif") ) == 0) ||
  
(strExt.CompareNoCase( TEXT("tif") ) == 0) ||
  
(strExt.CompareNoCase( TEXT("png") ) == 0) )
  
{
  
// save the image file name
  
VectorImageNames.push_back(strName);
  
}
  
}  
  

  
// loop through to add all of them to our vector
  
while (bRC)
  
{
  
bRC = ::FindNextFile(hFind, &FindFileData);
  
if (bRC)
  
{
  
// filter off the system files and directories
  
if (!(FindFileData.dwFileAttributes & FILE_ATTRIBUTE_DIRECTORY)  &&
  
!(FindFileData.dwFileAttributes & FILE_ATTRIBUTE_SYSTEM)     &&
  
!(FindFileData.dwFileAttributes & FILE_ATTRIBUTE_HIDDEN)     &&
  
!(FindFileData.dwFileAttributes & FILE_ATTRIBUTE_TEMPORARY))
  
{
  
// test file extension
  
strName = FindFileData.cFileName;
  
strExt = strName.Right(3);
  

  
if ( (strExt.CompareNoCase( TEXT("bmp") ) == 0) ||
  
(strExt.CompareNoCase( TEXT("jpg") ) == 0) ||
  
(strExt.CompareNoCase( TEXT("gif") ) == 0) ||
  
(strExt.CompareNoCase( TEXT("tif") ) == 0) ||
  
(strExt.CompareNoCase( TEXT("png") ) == 0) )
  
{
  
// save the image file name
  
VectorImageNames.push_back(strName);
  
}
  
}
  
}  
  
else
  
{
  
DWORD err = ::GetLastError();
  
if (err !=  ERROR_NO_MORE_FILES)
  
{
  
LPVOID msg;
  
::FormatMessage(FORMAT_MESSAGE_ALLOCATE_BUFFER | FORMAT_MESSAGE_FROM_SYSTEM, 
  
NULL, err, 
  
MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT),
  
(LPTSTR)&msg, 0, NULL);
  
MessageBox((LPTSTR)msg, CString((LPCSTR)IDS_TITLE), MB_OK|MB_ICONSTOP);
  
::LocalFree(msg);
  
::FindClose(hFind);
  
return FALSE;
  
}
  
}
  
} // end of while loop
  

  
// close the search handle
  
::FindClose(hFind);
  

  
// update the names, if any
  
if ( !VectorImageNames.empty() )
  
{
  
// reset the image name vector
  
m_VectorImageNames.clear();
  
m_VectorImageNames = VectorImageNames;
  
return TRUE;
  
}
  

  
return FALSE;
  
}
  

  
void  CListImageCtrl::DrawThumbnails()
  
{
  
CStringstrPath;
  
inti;
  

  
// no images
  
if (m_VectorImageNames.empty())
  
return;
  

  
// set the length of the space between thumbnails
  
// you can also calculate and set it based on the length of your list control
  
int nGap = 40;
  

  
// hold the window update to avoid flicking
  
SetRedraw(FALSE);
  

  
// reset our image list
  
for (i = 0; i < m_ImageListThumb.GetImageCount(); i++)
  
m_ImageListThumb.Remove(i);
  

  
// remove all items from list view
  
if (this->GetItemCount() != 0)
  
this->DeleteAllItems();
  

  
// set the size of the image list
  
m_ImageListThumb.SetImageCount(m_VectorImageNames.size());
  
i = 0;
  

  
// draw the thumbnails
  
std::vector<CString>::iterator
  
for (iter = m_VectorImageNames.begin(); iter != m_VectorImageNames.end(); iter++)
  
{
  
HBITMAP hbmReturn = NULL; 
  
Bitmap  *bmPhoto  = NULL;
  
CBitmap Bmp1;
  

  
// load the bitmap
  
strPath.Format( TEXT("%s\\%s"), m_strImageDir, *iter );
  

  
Bitmap img( strPath.AllocSysString() );
  

  
int sourceWidth  = img.GetWidth();
  
int sourceHeight = img.GetHeight();
  

  
int destX, destY, destWidth, destHeight;
  
const float fRatio=(float)THUMBNAIL_HEIGHT/THUMBNAIL_WIDTH;
  
const float fImgRatio=(float)sourceHeight/sourceWidth;
  

  
if(fImgRatio > fRatio)
  
{
  
destWidth=(THUMBNAIL_HEIGHT/fImgRatio);
  
destX=(THUMBNAIL_WIDTH-destWidth)/2;
  
destY=0;
  
destHeight=THUMBNAIL_HEIGHT;
  
}
  
else
  
{
  
destX=0;
  
destWidth=THUMBNAIL_WIDTH;
  
destHeight=(THUMBNAIL_WIDTH*fImgRatio);
  
destY=(THUMBNAIL_HEIGHT-destHeight)/2;
  
}
  

  
//check out very small image
  
if ((sourceHeight < THUMBNAIL_HEIGHT) && (sourceWidth < THUMBNAIL_WIDTH))
  
{
  
destWidth=sourceWidth;
  
destHeight=sourceHeight;
  
destX=(THUMBNAIL_WIDTH-destWidth)/2;
  
destY=(THUMBNAIL_HEIGHT-destHeight)/2;
  
}
  

  
bmPhoto = new Bitmap( THUMBNAIL_WIDTH, THUMBNAIL_WIDTH , PixelFormat32bppRGB );
  
bmPhoto->SetResolution( img.GetHorizontalResolution(), img.GetVerticalResolution() );
  

  
Graphics *grPhoto = Graphics::FromImage( bmPhoto );
  
Color colorW(255, 255, 255, 255);
  
Gdiplus::Pen pen(Color(200,192,192,192));
  
grPhoto->Clear( colorW );
  
grPhoto->SetInterpolationMode( InterpolationModeHighQualityBilinear );
  
grPhoto->DrawImage( &img, Rect(destX, destY, destWidth, destHeight) );
  
grPhoto->DrawRectangle(&pen,Gdiplus::Rect(0,0,THUMBNAIL_WIDTH-1,THUMBNAIL_HEIGHT-1));  //draw border
  

  
bmPhoto->GetHBITMAP( colorW, &hbmReturn );
  

  
Bmp1.Attach( hbmReturn );
  
m_ImageListThumb.Replace( i, &Bmp1, NULL );
  
//int imgP=m_ImageListThumb.Add(&Bmp1,RGB(0,0,0));
  

  
InsertItem(i, m_VectorImageNames[i],i);  //Link to the added listview item 
  

  
delete grPhoto;
  
delete bmPhoto;
  
Bmp1.Detach();
  
DeleteObject( hbmReturn );
  
i++;
  

  
}
  

  
// let's show the new thumbnails
  
SetRedraw(); 
  
}
  

  
void CListImageCtrl::Load() 
  
{
  
// TODO: Add your control notification handler code here
  
UpdateData(TRUE);
  

  
// validate image directory
  
if (m_strImageDir.IsEmpty())
  
{
  
MessageBox(CString((LPCSTR)IDS_DIR_ERROR), CString((LPCSTR)IDS_TITLE), MB_OK|MB_ICONSTOP);
  
return;
  
}
  

  
// show hour glass cursor
  
BeginWaitCursor();
  

  
// get the names of bitmap files
  
if ( !GetImageFileNames() )
  
{
  
EndWaitCursor();
  
return;
  
}
  

  
// draw thumbnail images in list control
  
DrawThumbnails();
  

  
// draw the selected image in its full size
  
//DrawSelectedImage();
  

  
// if this was a shortcut, we need to expand it to the target path
  
SetItemState(0, LVIS_SELECTED |    LVS_ICON | LVS_AUTOARRANGE, LVIS_SELECTED | LVIS_FOCUSED | LVIS_ACTIVATING); 
  
SetFocus();
  

  
RedrawWindow(NULL,NULL);
  

  
EndWaitCursor();
  

  
}
  

  
void CListImageCtrl::Clear()
  
{
  
// hold the window update to avoid flicking
  
SetRedraw(FALSE);
  

  
// reset our image list
  
for (int i = 0; i < m_ImageListThumb.GetImageCount(); i++)
  
m_ImageListThumb.Remove(i);
  

  
// remove all items from list view
  
if (this->GetItemCount() != 0)
  
this->DeleteAllItems();
  

  
m_strImageDir = _T("");
  

  
m_VectorImageNames.clear();
  

  
SetRedraw(); 
  

  
}



（2）、用法




1、在界面上放一个ListCtrl控件，设置View属性为ICON，Accept files属性TRUE，然后关联一个变量，如CListImageCtrl  m_lstImg;


2、在 BOOL CXXXDlg::OnInitDialog()初始化控件，一个语句就可以了m_lstImg.CreateColumn();


3、加载略缩图方法可以拖拽图片到控件，也可以这样加载


//strPath
  
  

  
m_lstImg.m_strImageDir = strPath;
  
m_lstImg.Load();

 

 


标签：控件,CompareNoCase,缩图,TEXT,CListImageCtrl,strExt,GDI,VectorImageNames,THUMBNAIL
From： https://blog.51cto.com/u_15911341/5934959

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