序
我自己是很喜歡用RSS的服務的人，所以寫網站或是做一些事時常會想到要弄個RSS Feed，最起碼自己會用的到~
不過VB中並沒有直接提供RSS Feed的產生函式，國外有些網站好像有提供類似的東西，不過不是要註冊就是有些複雜，所以我就自己寫了一個~
作法
我原本是用FileIO那篇的寫文字檔的方式，用比較笨的方法產生RSS Feed~
不過後來我改用以下的內容，將RSS的內容，以Xml.XmlDocument這個類別來產生XML的結構，順便學習在VB.Net下怎麼自己產生XML結構，並且它會自己將HTML編碼的問題解決
RSS 2.0的規格則是參考RSS 2.0 Specification中的規定，來設計RSS feed的元素，不過我剔除掉了一些我覺得沒用或是我看不出來功能的標籤，來產生結果
模組程式碼
Imports System
Module RSSGenModule
'''
''' RSSGenerator V1.0 is builded by Allen
''' Please get the newest information at
''' http://allen080.blogspot.com/
'''
Public Class RSSGenerator
Public Sub createRSS(ByRef rssfeed As RSSFeed, ByVal path As String)
'RSS 2.0 specification is Reference at
'http://www.rssboard.org/rss-specification/
Dim x As New Xml.XmlDocument
x.LoadXml("" + "" + "")
Dim channel As Xml.XmlElement = x.CreateElement("channel")
x.DocumentElement.AppendChild(channel)
Dim element As Xml.XmlElement
Dim subElement As Xml.XmlElement
'set channel start
element = x.CreateElement("title")
channel.AppendChild(element)
element.InnerText = rssfeed.title
If Not rssfeed.link Is Nothing Then
element = x.CreateElement("link")
channel.AppendChild(element)
element.InnerText = rssfeed.link
End If
If Not rssfeed.description Is Nothing Then
element = x.CreateElement("description")
channel.AppendChild(element)
element.InnerText = rssfeed.description
End If
If Not rssfeed.language Is Nothing Then
element = x.CreateElement("language")
channel.AppendChild(element)
element.InnerText = rssfeed.language
End If
If Not rssfeed.copyright Is Nothing Then
element = x.CreateElement("copyright")
channel.AppendChild(element)
element.InnerText = rssfeed.copyright
End If
If Not rssfeed.managingEditor Is Nothing Then
element = x.CreateElement("managingEditor")
channel.AppendChild(element)
element.InnerText = rssfeed.managingEditor
End If
If Not rssfeed.webMaster Is Nothing Then
element = x.CreateElement("webMaster")
channel.AppendChild(element)
element.InnerText = rssfeed.webMaster
End If
element = x.CreateElement("pubDate")
channel.AppendChild(element)
element.InnerText = (rssfeed.pubDate.AddHours(-8)).ToString("r")
element = x.CreateElement("lastBuildDate")
channel.AppendChild(element)
element.InnerText = (rssfeed.lastBuildDate.AddHours(-8)).ToString("r")
If Not rssfeed.category Is Nothing Then
element = x.CreateElement("category")
channel.AppendChild(element)
element.InnerText = rssfeed.category
End If
If Not rssfeed.generator Is Nothing Then
element = x.CreateElement("generator")
channel.AppendChild(element)
element.InnerText = rssfeed.generator
End If
If Not rssfeed.docs Is Nothing Then
element = x.CreateElement("docs")
channel.AppendChild(element)
element.InnerText = rssfeed.docs
End If
If Not rssfeed.image Is Nothing Then
element = x.CreateElement("image")
channel.AppendChild(element)
'set image start
If Not rssfeed.image.title Is Nothing Then
subElement = x.CreateElement("title")
element.AppendChild(subElement)
subElement.InnerText = rssfeed.image.title
End If
If Not rssfeed.image.link Is Nothing Then
subElement = x.CreateElement("link")
element.AppendChild(subElement)
subElement.InnerText = rssfeed.image.link
End If
subElement = x.CreateElement("url")
element.AppendChild(subElement)
subElement.InnerText = rssfeed.image.url
If Not rssfeed.image.description Is Nothing Then
subElement = x.CreateElement("description")
element.AppendChild(subElement)
subElement.InnerText = rssfeed.image.description
End If
'set image end
End If
If Not rssfeed.itmes Is Nothing Then
For Each item As RSSElement In rssfeed.itmes
element = x.CreateElement("item")
channel.AppendChild(element)
'set item start
subElement = x.CreateElement("title")
element.AppendChild(subElement)
subElement.InnerText = item.title
If Not item.link Is Nothing Then
subElement = x.CreateElement("link")
element.AppendChild(subElement)
subElement.InnerText = item.link
End If
If Not item.description Is Nothing Then
subElement = x.CreateElement("description")
element.AppendChild(subElement)
subElement.InnerText = item.description
End If
If Not item.author Is Nothing Then
subElement = x.CreateElement("author")
element.AppendChild(subElement)
subElement.InnerText = item.author
End If
If Not item.category Is Nothing Then
subElement = x.CreateElement("category")
element.AppendChild(subElement)
subElement.InnerText = item.category
End If
If Not item.comments Is Nothing Then
subElement = x.CreateElement("comments")
element.AppendChild(subElement)
subElement.InnerText = item.comments
End If
If Not item.guid Is Nothing Then
subElement = x.CreateElement("guid")
subElement.SetAttribute("isPermaLink", "false")
element.AppendChild(subElement)
subElement.InnerText = item.guid
End If
subElement = x.CreateElement("pubDate")
element.AppendChild(subElement)
subElement.InnerText = (item.pubDate.AddHours(-8)).ToString("r")
'set item end
Next
End If
'set channel end
'write to file
Dim settings As New Xml.XmlWriterSettings()
settings.Indent = True
settings.IndentChars = " "
settings.Encoding = System.Text.Encoding.UTF8
Using writer As Xml.XmlWriter = Xml.XmlWriter.Create(path, settings)
x.WriteTo(writer)
writer.Flush()
End Using
End Sub
End Class
Public Class RSSElement
Private _title As String
Private _link As String
Private _description As String
Private _author As String
Private _category As String
Private _comments As String
Private _guid As String
Private _pubDate As Date
Public Property pubDate() As Date
Get
Return _pubDate
End Get
Set(ByVal value As Date)
_pubDate = value
End Set
End Property
Public Property guid() As String
Get
Return _guid
End Get
Set(ByVal value As String)
_guid = value
End Set
End Property
'''
''' 回應的URL
'''
Public Property comments() As String
Get
Return _comments
End Get
Set(ByVal value As String)
_comments = value
End Set
End Property
Public Property category() As String
Get
Return _category
End Get
Set(ByVal value As String)
_category = value
End Set
End Property
'''
''' E-Mail
'''
Public Property author() As String
Get
Return _author
End Get
Set(ByVal value As String)
_author = value
End Set
End Property
Public Property description() As String
Get
Return _description
End Get
Set(ByVal value As String)
_description = value
End Set
End Property
Public Property title() As String
Get
Return _title
End Get
Set(ByVal value As String)
_title = value
End Set
End Property
Public Property link() As String
Get
Return _link
End Get
Set(ByVal value As String)
_link = value
End Set
End Property
End Class
Public Class RSSImage
Private _title As String
Private _link As String
Private _url As String
Private _description As String
Public Property description() As String
Get
Return _description
End Get
Set(ByVal value As String)
_description = value
End Set
End Property
Public Property url() As String
Get
Return _url
End Get
Set(ByVal value As String)
_url = value
End Set
End Property
Public Property link() As String
Get
Return _link
End Get
Set(ByVal value As String)
_link = value
End Set
End Property
Public Property title() As String
Get
Return _title
End Get
Set(ByVal value As String)
_title = value
End Set
End Property
End Class
Public Class RSSFeed
Private _title As String
Private _link As String
Private _description As String
Private _language As String = "zh-tw"
Private _copyright As String
Private _managingEditor As String
Private _webMaster As String
Private _guid As String
Private _pubDate As Date = Now
Private _lastBuildDate As Date = Now
Private _category As String
Private _generator As String
Private _docs As String = "http://www.rssboard.org/rss-specification"
Private _image As RSSImage
Private _items As ArrayList
'''
''' 元素型態是RSSElement
'''
Public Property itmes() As ArrayList
Get
Return _items
End Get
Set(ByVal value As ArrayList)
_items = value
End Set
End Property
Public Property image() As RSSImage
Get
Return _image
End Get
Set(ByVal value As RSSImage)
_image = value
End Set
End Property
'''
''' URL
'''
Public Property docs() As String
Get
Return _docs
End Get
Set(ByVal value As String)
_docs = value
End Set
End Property
Public Property generator() As String
Get
Return _generator
End Get
Set(ByVal value As String)
_generator = value
End Set
End Property
Public Property category() As String
Get
Return _category
End Get
Set(ByVal value As String)
_category = value
End Set
End Property
Public Property lastBuildDate() As Date
Get
Return _lastBuildDate
End Get
Set(ByVal value As Date)
_lastBuildDate = value
End Set
End Property
Public Property pubDate() As Date
Get
Return _pubDate
End Get
Set(ByVal value As Date)
_pubDate = value
End Set
End Property
Public Property guid() As String
Get
Return _guid
End Get
Set(ByVal value As String)
_guid = value
End Set
End Property
'''
''' E-Mail
'''
Public Property managingEditor() As String
Get
Return _managingEditor
End Get
Set(ByVal value As String)
_managingEditor = value
End Set
End Property
'''
''' E-Mail
'''
Public Property webMaster() As String
Get
Return _webMaster
End Get
Set(ByVal value As String)
_webMaster = value
End Set
End Property
Public Property copyright() As String
Get
Return _copyright
End Get
Set(ByVal value As String)
_copyright = value
End Set
End Property
Public Property language() As String
Get
Return _language
End Get
Set(ByVal value As String)
_language = value
End Set
End Property
Public Property description() As String
Get
Return _description
End Get
Set(ByVal value As String)
_description = value
End Set
End Property
Public Property title() As String
Get
Return _title
End Get
Set(ByVal value As String)
_title = value
End Set
End Property
Public Property link() As String
Get
Return _link
End Get
Set(ByVal value As String)
_link = value
End Set
End Property
End Class
End Module
使用方法
這個模組中主要有4個類別，分別是
- RSSFeed：整個RSS的資料都存在這裡面，如果沒有被設定到的屬性，就不會被寫入檔案中(日期除外)
- RSSImage：用來顯示Logo的資訊，如果沒有Logo就不要把它設定給RSSFeed就好了
- RSSElement：用來存每一筆新資訊的地方，在RSSFeed中是被ArrayList存起來的
- RSSGenerator：將路徑與RSSFeed交給其中的createRSS函式，就能產生一個RSS feed檔
使用範例
Dim rssfeed As New RSSFeed
rssfeed.title = title
rssfeed.link = url
rssfeed.description = title
rssfeed.generator = "倫倫3號"
rssfeed.webMaster = "allen080+Tech@gmail.com"
Dim rssimage As New RSSImage
rssfeed.image = rssimage
rssimage.title = title
rssimage.link = url
rssimage.url = url + "images/fslogo.jpg"
rssfeed.itmes = New ArrayList
Dim notes As ArrayList = gbdatas
For Each item As GuestBookData In notes
Dim rsselement As New RSSElement
rsselement.title = item.title
rsselement.author = item.eMail + " (" + item.name + ")"
rsselement.link = item.url
rsselement.description = item.content
rsselement.pubDate = item.time
rsselement.guid = item.url
rssfeed.itmes.Add(rsselement)
Next
Dim rssgen As New RSSGenerator
rssgen.createRSS(rssfeed, path)
總結
有這樣的一個類別就可以很快的產生出屬於自己的RSS Feed，當然這個xml檔要放在網頁伺服器上，我通常是用IIS就解決了~
完成的檔案可以透過Feed Validator for Atom and RSS這樣的網站來做驗證，不過如果只是一些小警告、小錯誤不理他也沒關係，只要你的RSS Reader不會讀不出來就好了
寫完這個RSS產生函式，如果有空我會找時間看看Atom的不同，如果有必要，也會寫Atom的版本~
參考連結
