使用 Google 日历与 VB.NET 和 ASP.NET

• 下载源代码 - 2.21 KB

引言

我搜索了又搜索，但找不到任何完整的示例，展示如何直接使用 Google 日历 API。因此，在从许多不同的示例中拼凑出我的解决方案后，我决定发布这个小型项目，既是为了巩固我自己的方法，也是为了帮助其他可能也需要这样做的人。

背景

我有几篇类似的参考文章，其中一篇是在 The Code Project 上发布的：使用 Google 日历与 ASP.NET，作者是 Igor Alekseev。

事实上，在我找到他的文章之前，我一直很难让我的事件进入我希望它们进入的特定日历，而 Igor 的代码是我遇到的第一个清楚地定义了 Google 服务哪些 URIs 的代码。

我有点模仿了 Igor 的方法，将 CalendarService 对象 ByRef 传递给后续函数，因为这对于避免被 Google 禁封至关重要，这可能会在您的测试过程中产生一些有趣的错误！

然而，最重要的是，也许是他对这行代码的直觉

calFeed.Entries(x).Id.AbsoluteUri.Substring(63) 

在我发现 "substring(63)" 之前，我一直很难获得可靠的日历 ID！

谢谢 Igor！

Using the Code

我努力在这个代码中维护两种不同的方法，一种是单次调用，另一种是复合调用... 单次调用用于我自己的应用程序，例如，当向我们的数据库表中添加新行时。我可以进行一次调用并将该数据推送到日历... 这种方法也使其非常适合 Web 服务调用。当您需要从客户端代码执行多个步骤时，另一种方法很好，它允许您在一个调用中获取您的 CalendarService 对象，然后在您的后续操作中持续重用它，这样您的登录就不会针对 Google 每次调用都重复。

单次调用通常是这样的

Dim g As New GoogleCalSvc, str as String
str = g.A1ListMyCalendars

而多次或复合调用可能看起来像这样

Dim g As New GoogleCalendar_KellyTours, str as string
str = str & g.FindEvent(g.GetCalendarService, "123")

或者甚至像这样，其中服务对象 s 被重复使用

Dim g As New GoogleCalSvc
Dim s = g.GetCalendarService
Dim out As String = g.FindEvent(s, "Primary", "123")
out = out & g.FindEvent(s, "Primary", "456")
out = out & g.FindEvent(s, "Primary", "789")
Me.output.InnerHtml = out

关注点

一旦你克服了互联网上大多数代码和文档都是针对 C# 项目的事实，稍加努力，你最终会发现该 API 实际上非常容易使用。随着持续的开发，这个项目可以很容易地发展成为一个完整的日历访问封装接口。

在我自己的使用中，我也有额外的数据库代码就在这个文件中，所以我可以只将记录 ID 传递给一些函数，它们会自动以一种相当实时的模式将所需记录发布、更新等，到/从日历。

代码列表

Imports System.IO
Imports System.Data.SqlClient

Imports System.Web.Services
Imports System.Web.Services.Protocols
Imports System.ComponentModel

'Imports Google.GData.AccessControl
Imports Google.GData.Calendar
Imports Google.GData.Client
Imports Google.GData.Extensions

' To allow this Web Service to be called from script,
' using ASP.NET AJAX, uncomment the following line.
' <System.Web.Script.Services.ScriptService()> _
<System.Web.Services.WebService(Namespace:="https:///GoogleCalendarInVBNET/")> _
<System.Web.Services.WebServiceBinding(ConformsTo:=WsiProfiles.BasicProfile1_1)> _
<ToolboxItem(False)> _
Public Class GoogleCalSvc
    Inherits System.Web.Services.WebService

    Private Const userName As String = "SomeUser@GMailOrGoogleAppsDomain.com"
    Private Const userPassword As String = "SomeStrongPassword"

    '' Here's the feed to access events on the users' private/primar calendar:
    Private feedUri As String = _
      "https://www.google.com/calendar/feeds/default/private/full?max-results=9999"
    '' Here's the feed that lists all calendars that this user has access to:
    Private Const feedOwnCalendars As String = _
      "https://www.google.com/calendar/feeds/default/owncalendars/full"
    '' This is a feed for non-primary calendars that requires an ID field,
    '' taken from enumerating the users' calendars...
    Private Const CALENDAR_TEMPLATE As String = _
       "https://www.google.com/calendar/feeds/{0}/private/full?max-results=9999"

#Region "Single Call Public Functions"

    <WebMethod()> _
    Public Function A1ListMyCalendars() As String
        Dim str As String
        str = ListAllCalendars()
        Return str
    End Function

    <WebMethod()> _
    Public Function A1CreateEvent(ByVal stCalName As String, ByVal strWhere As String, _
           ByVal strStart As String, ByVal strEnd As String, _
           ByVal strSubject As String, ByVal strBody As String, _
           ByVal strRecurData As String) As String
        Return CreateEvent(GetCalendarService, stCalName, strWhere, _
               strStart, strEnd, strSubject, strBody, strRecurData)
    End Function

    <WebMethod()> _
    Public Function A1DeleteEvent(ByVal intTripNo As Integer, ByVal stCalName As String) As String
        Return DeleteEvent(GetCalendarService, intTripNo, stCalName)
    End Function

    <WebMethod()> _
    Public Function A1ListUsersCalendars() As String
        Dim Service As CalendarService = GetCalendarService()
        Dim query As New FeedQuery
        query.Uri = New Uri(feedUri) ' Private feedUri 'cause for users calendars

        Dim calFeed As AtomFeed
        calFeed = Service.Query(query)

        Dim str As String = ""
        For x As Integer = 0 To calFeed.Entries.Count - 1
            str = str & calFeed.Entries(x).Title.Text
            If calFeed.Entries.Count > 1 And x < (calFeed.Entries.Count - 1) Then
                str = str & ", " & calFeed.Title.Text & vbCrLf
            End If
        Next

        Return str
    End Function

#End Region

#Region "Public GET Functions"

    Public Function GetCalendarService() As CalendarService
        Dim Service As CalendarService = New CalendarService("My-exampleApp-1")
        Service.setUserCredentials(userName, userPassword)
        Return Service
    End Function

    <WebMethod()> _
    Public Function GetCalendarID(ByRef Service As CalendarService, ByVal strCalName As String) As String
        Dim query As New FeedQuery
        Dim str As String = ""

        query.Uri = New Uri(feedOwnCalendars)

        Dim calFeed As AtomFeed
        calFeed = Service.Query(query)

        For x As Integer = 0 To calFeed.Entries.Count - 1
            If calFeed.Entries(x).Title.Text = strCalName Then
                str = calFeed.Entries(x).Id.AbsoluteUri.Substring(63)
            End If
        Next

        Return str
    End Function

    <WebMethod()> _
    Public Function GetCalendarURI(ByRef Service As CalendarService, ByVal stCalName As String) As String
        Dim stURI As String = String.Format(CALENDAR_TEMPLATE, GetCalendarID(Service, stCalName))
        '' Easy override to go back to the users' primary calendar!!!
        If stCalName = "Primary" Then
            stURI = feedUri
        End If
        Return stURI
    End Function
#End Region

    <WebMethod()> _
    Public Function ListAllCalendars() As String
        Dim Service As CalendarService = GetCalendarService()
        Dim query As New FeedQuery
        query.Uri = New Uri(feedOwnCalendars)

        Dim calFeed As AtomFeed
        calFeed = Service.Query(query)

        Dim str As String = ""
        For x As Integer = 0 To calFeed.Entries.Count - 1
            str = str & calFeed.Entries(x).Title.Text & "|" & _
                  calFeed.Entries(x).Id.AbsoluteUri.Substring(63) & vbCrLf
        Next

        Return str
    End Function

    <WebMethod()> _
    Public Function DeleteAllEvents(ByVal strCalName As String) As String

        Dim str As String = ""

        Dim Service As CalendarService = GetCalendarService()
        Dim query As New FeedQuery
        query.Uri = New Uri(GetCalendarURI(Service, strCalName))

        Dim calFeed As AtomFeed
        calFeed = Service.Query(query)

        If calFeed.Entries.Count > 0 Then
            For x As Integer = 0 To calFeed.Entries.Count - 1
                str = str & calFeed.Entries(x).Title.Text & vbCrLf
                calFeed.Entries(x).Delete()
            Next
        End If

        Return str

    End Function

    Public Function DeleteEvent(ByRef Service As CalendarService, _
           ByVal strSearchFor As String, ByVal stCalName As String) As String

        Dim str As String = ""

        Dim query As New FeedQuery
        query.Uri = New Uri(GetCalendarURI(Service, stCalName))
        query.Query = strSearchFor

        Dim sFeed As EventFeed = Service.Query(query)
        Dim Exists As Boolean = False

        If sFeed.TotalResults > 0 Then
            Exists = True

            Dim calFeed As AtomFeed
            calFeed = Service.Query(query)

            If calFeed.Entries.Count > 0 Then
                For x As Integer = 0 To calFeed.Entries.Count - 1
                    str = str & calFeed.Entries(x).Title.Text
                    calFeed.Entries(x).Delete()
                Next
            End If
        End If

        Return str

    End Function

    Private Function CreateEvent(ByRef Service As CalendarService, _
                                        ByVal strCalName As String, _
                                        ByVal strWhere As String, _
                                        ByVal strStart As String, _
                                        ByVal strEnd As String, _
                                        ByVal strSubject As String, _
                                        ByVal strBody As String, _
                                        ByVal strRecurData As String) As String

        Dim entry As New EventEntry
        entry.Title.Text = strSubject
        entry.Content.Content = strBody

        Dim eventLocation As New Where
        eventLocation.ValueString = strWhere
        entry.Locations.Add(eventLocation)

        Dim eventTime As New [When](strStart, strEnd)
        entry.Times.Add(eventTime)

        Dim postUri As Uri = New Uri(GetCalendarURI(Service, strCalName))
        Dim insertedEntry As AtomEntry = Service.Insert(postUri, entry)

        Return insertedEntry.ToString

    End Function

    Public Function FindEvent(ByRef Service As CalendarService, _
           ByVal strCalName As String, ByVal strSearchFor As String) As String
        Dim strOut As String = ""
        Dim query As EventQuery = New EventQuery

        query.Uri = New Uri(GetCalendarURI(Service, strCalName))
        query.Query = strSearchFor.ToString

        Dim calFeed As EventFeed = Service.Query(query)
        Dim feedEntry As EventEntry
        If calFeed.TotalResults > 0 Then

            For Each feedEntry In calFeed.Entries
                strOut = strOut & (feedEntry.Title.Text) & vbCrLf
            Next
        Else
            strOut = "No Results found"
        End If

        Return strOut
    End Function

    <WebMethod()> _
    Public Function ListUserEvents() As String
        Dim strOut As String = ""
        Dim query As EventQuery = New EventQuery
        Dim service As CalendarService = GetCalendarService()

        query.Uri = New Uri(GetCalendarURI(service, "Primary"))

        Dim calFeed As EventFeed = service.Query(query)
        Dim feedEntry As EventEntry

        For Each feedEntry In calFeed.Entries
            strOut = strOut & (feedEntry.Title.Text) & vbCrLf
        Next

        Return strOut

    End Function

    <WebMethod()> _
    Public Function ListEvents(ByVal strCalName As String) As String
        Dim strOut As String = ""
        Dim query As EventQuery = New EventQuery
        Dim Service As CalendarService = GetCalendarService()

        query.Uri = New Uri(GetCalendarURI(Service, strCalName))

        Dim calFeed As EventFeed = Service.Query(query)
        Dim feedEntry As EventEntry

        For Each feedEntry In calFeed.Entries
            strOut = strOut & (feedEntry.Title.Text) & vbCrLf
            ' list the event title in a messagebox...
        Next

        Return strOut

    End Function

    <WebMethod()> _
    Public Function DeDupeEvents(ByVal strCalName As String) As String
        Dim strOut As String = "", strVal As String = ""
        Dim vals As New Collection
        ' list all the events....
        Dim query As EventQuery = New EventQuery
        Dim service As CalendarService = GetCalendarService()
        query.Uri = New Uri(GetCalendarURI(service, strCalName))

        Dim calFeed As EventFeed = service.Query(query)
        Dim feedEntry As EventEntry

        For Each feedEntry In calFeed.Entries
            strVal = (feedEntry.Title.Text)

            If Not vals.Contains(strVal) Then
                strOut = strOut & strVal
                vals.Add(strVal, strVal)
            Else
                feedEntry.Delete()
            End If

        Next

        Return strOut

    End Function
End Class

历史

• 2011年12月31日 - 这是我第一次发布这篇文章和代码，并且我相信在将其与我应用程序的其余部分分开之后，将需要进行一些更新。