在ASP.NET 使用WebDAV访问Outlook的日历
在很多公司里，会议室的预定是通过Outlook的Public文件夹实现的，但是如果你需要会议室的同时，也需要投影仪和笔记本，那么你至少需要预定三处，Dotnetcms提供的会议室预定系统则很好的解决这个问题，演示地址为 http://demo.dotnetcms.org/dotnetcms/book/Viewcalendar.aspx （我们的主页地址为 http://www.dotnetcms.org ）
在会议室预定里，实现了和Outlook的同步，这里使用了WebDAV协议，使用它可以对Outlook的日历进行读写。
当访问Outlook的calendar的Uri时，首先需要建立一个Table来存放返回的数据，为此定义了一个CreateDataTable方法，如下
#region 创建一个临时表来存放日历Calendar信息
public DataTable CreateDataTable()
{
System.Data.DataTable table = new DataTable("calendar");
DataColumn column;
// Create new DataColumn, set DataType,
// ColumnName and add to DataTable.
column = new DataColumn();
column.DataType = System.Type.GetType("System.Int32");
column.ColumnName = "id";
column.AutoIncrement = true;
column.ReadOnly = true;
column.Unique = true;
table.Columns.Add(column);
// Create second column.
column = new DataColumn();
column.DataType = System.Type.GetType("System.String");
column.ColumnName = "subject";
column.AutoIncrement = false;
column.Caption = "subject";
column.ReadOnly = false;
column.Unique = false;
// Add the column to the table.
table.Columns.Add(column);
// Create 3 column.
column = new DataColumn();
column.DataType = System.Type.GetType("System.String");
column.ColumnName = "location";
column.AutoIncrement = false;
column.Caption = "location";
column.ReadOnly = false;
column.Unique = false;
// Add the column to the table.
table.Columns.Add(column);
// Create 4 column.
column = new DataColumn();
column.DataType = System.Type.GetType("System.String");
column.ColumnName = "dtstart";
column.AutoIncrement = false;
column.Caption = "dtstart";
column.ReadOnly = false;
column.Unique = false;
// Add the column to the table.
table.Columns.Add(column);
// Create second column.
column = new DataColumn();
column.DataType = System.Type.GetType("System.String");
column.ColumnName = "dtend";
column.AutoIncrement = false;
column.Caption = "dtend";
column.ReadOnly = false;
column.Unique = false;
// Add the column to the table.
table.Columns.Add(column);
// Create second column.
column = new DataColumn();
column.DataType = System.Type.GetType("System.String");
column.ColumnName = "busystatus";
column.AutoIncrement = false;
column.Caption = "busystatus";
column.ReadOnly = false;
column.Unique = false;
// Add the column to the table.
table.Columns.Add(column);
// Create second column.
column = new DataColumn();
column.DataType = System.Type.GetType("System.String");
column.ColumnName = "instancetype";
column.AutoIncrement = false;
column.Caption = "instancetype";
column.ReadOnly = false;
column.Unique = false;
// Add the column to the table.
table.Columns.Add(column);
// Make the ID column the primary key column.
DataColumn[] PrimaryKeyColumns = new DataColumn[1];
PrimaryKeyColumns[0] = table.Columns["id"];
table.PrimaryKey = PrimaryKeyColumns;
return table;
}
#endregion
接下来，就需要从Exchange 服务器上抓取数据，在这里WebDAV除了支持Http轻求常用的GET、POST、HEAD等方法外，还额外提供了几个谓词，下面就是使用“Search”方法来从服务器上获取数据
strQuery = "<?xml version=\"1.0\"?>"
+ "<g:searchrequest xmlns:g=\"DAV:\">"
+ "<g:sql>SELECT \"urn:schemas:calendar:location\", \"urn:schemas:httpmail:subject\", "
+ "\"urn:schemas:calendar:dtstart\", \"urn:schemas:calendar:dtend\", "
+ "\"urn:schemas:calendar:busystatus\", \"urn:schemas:calendar:instancetype\" "
+ "FROM Scope('SHALLOW TRAVERSAL OF \"" + strCalendarURI + "\"') "
+ "WHERE NOT \"urn:schemas:calendar:instancetype\" = 1 "
+ " and \"DAV:contentclass\" = 'urn:content-classes:appointment' "
+ "AND \"urn:schemas:calendar:dtend\" > '" + dt + "' "
+ "ORDER BY \"urn:schemas:calendar:dtstart\" ASC"
+ "</g:sql></g:searchrequest>";
如果你仔细看，你会发现他的查询预防和SQL非常类似， select url:schemas:calendar:location ... from scope() where not
这和数据库的SQL几乎一样
MyCredentialCache = new System.Net.CredentialCache();
MyCredentialCache.Add(new System.Uri(strCalendarURI), "NTLM", new System.Net.NetworkCredential(System.Web.Configuration.WebConfigurationManager.AppSettings["username"].ToString(), System.Web.Configuration.WebConfigurationManager.AppSettings["password"].ToString(), System.Web.Configuration.WebConfigurationManager.AppSettings["domain"].ToString()));
Request = (System.Net.HttpWebRequest)HttpWebRequest.Create(strCalendarURI);
Request.Credentials = MyCredentialCache;
Request.Method = "SEARCH";
bytes = Encoding.UTF8.GetBytes((string)strQuery);
Request.ContentLength = bytes.Length;
RequestStream = Request.GetRequestStream();
RequestStream.Write(bytes, 0, bytes.Length);
RequestStream.Close();
Request.KeepAlive=true;
Request.Headers.Set("Pragma", "no-cache");
Request.ContentType = "text/xml";
Request.Timeout = 300000;
Response = (HttpWebResponse)Request.GetResponse();
ResponseStream = Response.GetResponseStream();
ResponseXmlDoc = new XmlDocument();
ResponseXmlDoc.Load(ResponseStream);
获取数据后，就需要把数据存放到刚才我们建立的临时表里，
SubjectNodeList = ResponseXmlDoc.GetElementsByTagName("e:subject");
LocationNodeList = ResponseXmlDoc.GetElementsByTagName("d:location");
StartTimeNodeList = ResponseXmlDoc.GetElementsByTagName("d:dtstart");
EndTimeNodeList = ResponseXmlDoc.GetElementsByTagName("d:dtend");
BusyStatusNodeList = ResponseXmlDoc.GetElementsByTagName("d:busystatus");
InstanceTypeNodeList = ResponseXmlDoc.GetElementsByTagName("d:instancetype");
DataTable table = CreateDataTable();
if (SubjectNodeList.Count > 0)
{
for (int i = 0; i < SubjectNodeList.Count; i++)
{
DataRow row;
row = table.NewRow();
row["subject"] = SubjectNodeList[i].InnerText;
row["location"] = LocationNodeList[i].InnerText;
row["dtstart"] = StartTimeNodeList[i].InnerText;
row["dtend"] = EndTimeNodeList[i].InnerText;
row["busystatus"] = BusyStatusNodeList[i].InnerText;
row["instancetype"] = InstanceTypeNodeList[i].InnerText;
table.Rows.Add(row);
}
}
ResponseStream.Close();
Response.Close();
return table;
}
这样，数据就获取成功了，当你一旦获取成功后，就可以进行各种操作了。
接下来，我们就可以把数据绑定到Grdiview1上进行显示或者各种样式处理，当然更推荐你使用DayPiolet控件，这样就可以让自定义的日历与Outlook同步。
绑定DayPiolet预览效果的地址为 http://demo.dotnetcms.org/dotnetcms/book/Viewcalendar.aspx （注意：这里的演示是使用MSSQL 数据库为基础，因为空间根本没有Exchange 服务器，这里只是模拟）
