VC中图像控件的用法与总结

1、使用picture控件动态显示图片方法一 控件适应于图片尺寸添加一个picture控件，修改id为idc-picture,并添加一cbitmap m_bmp成员变量在oninitdialog()函数中添加如下代码if(m_bmp.m_hobject!=null) m_bmp.deleteobject();/以绝对路径加载bmp图片hbitmap hbmp=(hbitmap):loadimage(afxgetinstancehandle(),1.bmp,image_bitmap,0,0,lr_createdibsection | lr_loadfromfile);if(hbmp=null) re

2、turn false;/获得加载位图的文件信息m_bmp.attach(hbmp);dibsection ds;bitmapinfoheader &bminfo=ds.dsbmih;/获得位图信息图m_bmp.getobject(sizeof(ds),&ds);int cx=bminfo.biwidth;/获得位图宽度int cy=bminfo.biheight;/获得位图高度/该段程序根据图象的宽和高，调整控件大小，让它正好显示一张图片crect rect;getdlgitem(idc_pictrue)-getwindowrect(&rect);/获得控件所在矩形区域screentoclie

3、nt(&rect);getdlgitem(idc_pictrue)-movewindow(rect.left,rect.top,cx,cy,true);/调整控件大小在onpaint()函数中添加如下代码/三种方法获得pictrue控件dc，图象将被绘制在控件上cpaintdc dc(getdlgitem(idc_pictrue);/cpaintdc dc(this);/cdc dc;/dc.m_hdc=:getdc(null);crect rcclient;getdlgitem(idc_pictrue)-getclientrect(&rcclient);cdc memdc;memdc.cre

4、atecompatibledc(&dc);cbitmap bitmap;bitmap.createcompatiblebitmap(&dc,rcclient.width(),rcclient.height();memdc.selectobject(&bitmap);cwnd:defwindowproc(wm_paint,(wparam)memdc.m_hdc,0); cdc maskdc;maskdc.createcompatibledc(&dc);cbitmap maskbitmap;maskbitmap.createbitmap(rcclient.width(),rcclient.heig

5、ht(),1,1,null);maskdc.selectobject(&maskbitmap);maskdc.bitblt(0,0,rcclient.width(),rcclient.height(),&memdc,rcclient.left,rcclient.top,srccopy);cbrush brush;brush.createpatternbrush(&m_bmp);dc.fillrect(rcclient,&brush);dc.bitblt(rcclient.left,rcclient.top,rcclient.width(),rcclient.height(),&memdc,rc

6、client.left,rcclient.top,srcpaint);brush.deleteobject();二 图片适用于控件尺寸 添加一个picture控件，修改id为idc-picture在onpaint()函数中添加如下代码cwnd *pwnd=getdlgitem(idc_pictrue);/获得pictrue控件窗口的句柄crect rect;pwnd-getclientrect(&rect);/获得pictrue控件所在的举行区域cdc *pdc=pwnd-getdc();/获得pictrue控件的dcistream *pstm;cfilestatus fstatus;cfil

7、e file;long cb;ipicture *ppic;/定义显示图片的接口（可显示jpg格式图片）cstring m_spath=1.bmp;/设置想要显示的图片/打开图象文件，获取文件字节数if(file.open(m_spath,cfile:moderead) & file.getstatus(m_spath,fstatus) & (cb=fstatus.m_size)!=-1) /分配全局存储空间 hglobal hglobal=globalalloc(gmem_moveable,cb); lpvoid pvdata=null; if(hglobal!=null) /锁定分配内存块

8、 if(pvdata=globallock(hglobal)!=null) /读入文件到内存缓冲区 file.readhuge(pvdata,cb); globalunlock(hglobal); createstreamonhglobal(hglobal,true,&pstm); /装载图象文件if(succeeded(oleloadpicture(pstm,fstatus.m_size,true,iid_ipicture,(lpvoid*)&ppic) ole_xsize_himetric hmwidth; ole_xsize_himetric hmheight; ppic-get_wid

9、th(&hmwidth);/获得图象真实宽度 ppic-get_height(&hmheight);/获得图象真实高度 /在控件上显示图片 ppic-render(*pdc,0,0,rect.width(),rect.height(),0,hmheight,hmwidth,-hmheight,null); ppic-release();图片显示通用模块首先为类添加如下两个函数和一个成员变量ipicture* m_ppicture;/图片加载函数hresult loadfrombuffer(byte *pbuff, int nsize)bool bresult=false;hglobal hgl

10、obal=globalalloc(gmem_moveable,nsize);/分配内存空间void *pdata=globallock(hglobal);/定义图象数据指针memcpy(pdata,pbuff,nsize);globalunlock(hglobal);/释放内存空间istream *pstream=null;/定义数据流指针/创建数据流if(createstreamonhglobal(hglobal,true,&pstream)=s_ok)hresult hr;/定义返回结果if(hr=oleloadpicture(pstream,nsize,false,iid_ipictur

11、e,(lpvoid*)&m_ppicture)=s_ok)bresult=true;pstream-release();/释放数据流return bresult;/图片显示函数bool drawfromfile(cstring filename, cdc *pdc)cfile cfile;cfileexception e;/打开文件if(cfile.open(filename,cfile:moderead | cfile:typebinary,&e)byte *pbuff=new bytecfile.getlength();/定义分配内存if(cfile.read(pbuff,cfile.ge

12、tlength()0)/将文件读入缓存loadfrombuffer(pbuff,cfile.getlength();delete pbuff;/释放缓存long hmwidth,hmheight;m_ppicture-get_width(&hmwidth);m_ppicture-get_height(&hmheight);/获取图片尺寸int nwidth=muldiv(hmwidth,pdc-getdevicecaps(logpixelsx),2540);int nheight=muldiv(hmheight,pdc-getdevicecaps(logpixelsx),2540);/在内存中

13、画cdc mendc;cbitmap bmp;bmp.createcompatiblebitmap(pdc,nwidth,nheight);mendc.createcompatibledc(null);mendc.selectobject(&bmp);m_ppicture-render(mendc.m_hdc,0,0,nwidth,nheight,0,hmheight,hmwidth,-hmheight,null);/将内存中画拷贝到目的地pdc-bitblt(0,0,nwidth,nheight,&mendc,0,0,srccopy);return true;然后在onpaint()函数中显示void cdialogdlg:onpaint() cpaintdc dc(this); / device context for paintingif (isiconic()sendmessage(wm_iconerasebkgnd, (wparam) dc.getsafehdc(), 0);/ center icon in client rectangleint cxicon = getsystemmetrics(sm_cxicon);int cyicon = getsystemmetrics(sm_cyicon);crect rect;getcl