数字图像处理实习实验1 cfile.pdfVIP

CFile::CFile

CFile();

CFile(inthFile);

CFile(LPCTSTRlpszFileName,UINTnOpenFlags);

throw(CFileException);

Parameters

hFile

Thehandleofafilethatisalreadyopen.

lpszFileName

Astringthatisthepathtothedesiredfile.Thepathcanberelativeorabsolute.

nOpenFlags

Sharingandaccessmode.Specifiestheactiontotakewhenopeningthefile.You

cancombineoptionslistedbelowbyusingthebitwise-OR(|)operator.One

accesspermissionandoneshareoptionarerequired;themodeCreateand

modeNoInheritmodesareoptional.Thevaluesareasfollows:

•CFile::modeCreateDirectstheconstructortocreateanewfile.Ifthe

fileexistsalready,itistruncatedto0length.

•CFile::modeNoTruncateCombinethisvaluewithmodeCreate.Ifthe

filebeingcreatedalreadyexists,itisnottruncatedto0length.Thusthe

fileisguaranteedtoopen,eitherasanewlycreatedfileorasanexisting

file.Thismightbeuseful,forexample,whenopeningasettingsfilethat

mayormaynotexistalready.ThisoptionappliestoCStdioFileaswell.

•CFile::modeReadOpensthefileforreadingonly.

•CFile::modeReadWriteOpensthefileforreadingandwriting.

•CFile::modeWriteOpensthefileforwritingonly.

•CFile::modeNoInheritPreventsthefilefrombeinginheritedbychild

processes.

•CFile::shareDenyNoneOpensthefilewithoutdenyingotherprocesses

readorwriteaccesstothefile.Createfailsifthefilehasbeenopenedin

compatibilitymodebyanyotherprocess.

•CFile::shareDenyReadOpensthefileanddeniesotherprocessesread

accesstothefile.Createfailsifthefilehasbeenopenedincompatibility

modeorf