一些比较实用的小函数

扫描文件夹极其子目录,列出所有文件,已经测试通过,绝对可用

procedure FindAllFile(const Dir: string;List: TStringlist);
var
  hFindFile: THandle;
  FindFileData: WIN32_FIND_DATA;
  FullName,FName,s:string;
begin
  s:=IncludeTrailingPathDelimiter(Dir);
  hFindFile := FindFirstFile(pchar(s+'*.*'), FindFileData);
  if hFindFile <> 0 then
  begin
    repeat
      FName:=FindFileData.cFileName;
      FullName:=s+FName;
      if (FName='.') or (FName='..') then continue;
      if (FindFileData.dwFileAttributes and FILE_ATTRIBUTE_DIRECTORY) = FILE_ATTRIBUTE_DIRECTORY then
        FindAllFile(FullName,List)
      else
        begin
          List.Add(FullName);
        end;
    until FindNextFile(hFindFile, FindFileData) = false;
    windows.FindClose(hFindFile);
  end;
end;

删除目录及其子目录和文件

function DeleteDirectory(NowPath:   string):   Boolean;
  var
      search:   TSearchRec;
      ret:   integer;
      key:   string;
  begin
      if NowPath[Length(NowPath)]<>'\' then
        NowPath:=NowPath+'\';
        key:=Nowpath+'*.*';
        ret:=findFirst(key,faanyfile,search);
      while ret=0 do
      begin
        if((search.Attr and fadirectory) = faDirectory)then
        begin
          if(Search.Name<>'.')and(Search.name<>'..')then
            DeleteDirectory(NowPath   +   Search.name);
        end
        else
        begin
          if((search.attr and fadirectory)<>fadirectory)then
             begin
               deletefile(NowPath   +   search.name);
             end;
          end;
        ret:=FindNext(search);
      end;
      findClose(search);
      removedir(NowPath);
      result:=True;
  end;

获取文件扩展名

function ExtractExteName(const FileName: string): string;
var
  P: Integer;
begin
  P := Length(FileName);
  while (P > 0)and(FileName[P] <> '.') do
      Dec(P);
  Result := Copy(FileName, P, Length(FileName)-P+1);
end;

判断文件是否存在

function FileExists(const FileName: string): Boolean;
  function FileAge(const FileName: string): Integer;
  type
    LongRec = packed record
      case Integer of
        0: (Lo, Hi: Word);
        1: (Words: array [0..1] of Word);
        2: (Bytes: array [0..3] of Byte);
    end;
  var
    Handle: THandle;
    FindData: TWin32FindData;
    LocalFileTime: TFileTime;
  begin
    Handle := FindFirstFile(PChar(FileName), FindData);
    if Handle <> INVALID_HANDLE_VALUE then
    begin
      Windows.FindClose(Handle);
      if (FindData.dwFileAttributes and FILE_ATTRIBUTE_DIRECTORY) = 0 then
      begin
        FileTimeToLocalFileTime(FindData.ftLastWriteTime, LocalFileTime);
        if FileTimeToDosDateTime(LocalFileTime, LongRec(Result).Hi, LongRec(Result).Lo) then
          Exit;
      end;
    end;
    Result := -1;
  end;
begin
  Result := FileAge(FileName) <> -1;
end;