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Wednesday, March 5, 2014

Call Statement VB.NET Example

VB.NET > Statements > Call


Call transfers control to a function or dynamic-link library.
Call keyword is used when the called expression doesn't start with an identifier.


Example:


Class mClass
    Public Sub Method()
        MessageBox.Show("Call statement")
    End Sub
End Class

Public Class Form1
    Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load
        Call New mClass().Method()
    End Sub

End Class





Tuesday, March 4, 2014

HttpResponse ASP.NET

ASP.NET > System.WebHttpResponse 

Encapsulates HTTP response information from an ASP.NET application.





ASP.NET System.Web

ASP.NET > System.Web

System.Web contains classes and interfaces that enable browser-server communication.





Rss Feed Reader Vb.net Example

VB.NET > XML > Rss Feed Reader






Example


 Dim url As String = "http://rss.cnn.com/rss/cnn_latest.rss"
        Dim rssFeed As HttpWebRequest = DirectCast(WebRequest.Create(url), HttpWebRequest)
        Dim response = rssFeed.GetResponse()
        Dim rssStream = response.GetResponseStream()

        Dim rssDoc As New XmlDocument()
        rssDoc.Load(rssStream)
        Dim rssItems As XmlNodeList = rssDoc.SelectNodes("rss/channel/item")
        Dim i As Integer = 0
        Dim dt As DataTable = New DataTable("table")
        dt.Columns.Add("title", Type.GetType("System.String"))
        dt.Columns.Add("link", Type.GetType("System.String"))

        While i < rssItems.Count
            Dim node As XmlNode = rssItems.Item(i).SelectSingleNode("title")
            Dim title As String
            Dim link As String
            If node IsNot Nothing Then
                title = node.InnerText
            Else
                title = ""
            End If

            node = rssItems.Item(i).SelectSingleNode("link")
            If node IsNot Nothing Then
                link = node.InnerText
            Else
                link = ""
            End If
            Dim dr As DataRow = dt.NewRow()
            dr("title") = title
            dr("link") = link

            dt.Rows.Add(dr)

            i += 1
        End While

        DataGridView1.DataSource = dt


#Region Directive Visual Basic Example

Visual Basic > Directives > #Region

Collapses and hides sections of code.

Example:

Public Class Form1
#Region "Person"
    Public Class Person

    End Class
#End Region
    Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load

    End Sub

End Class








Wednesday, February 26, 2014

Read XMLTYPE Oracle C#

C# > Oracle.DataAccess > Read XMLTYPE 

An OracleXmlType object represents an Oracle XMLType instance.

Example:


OracleConnection con = new OracleConnection() ;
con.ConnectionString = "Data Source=sid; User ID=xx; Password=xx; enlist=false; ";
con.Open();
OracleCommand xmlCmd = new OracleCommand();
xmlCmd.CommandText = "select xml from table ";
xmlCmd.Connection = con;
OracleDataReader poReader = xmlCmd.ExecuteReader();
OracleXmlType poXml;
while (poReader.Read())
{
     poXml = poReader.GetOracleXmlType(0);    
}

con.Close();




Tuesday, February 25, 2014

c# GuidAttribute Example

C# > InteropServices >  GuidAttribute 

Supplies an explicit Guid when an automatic GUID is undesirable.

When you write an application to be used as COM you have 
to give a unique name. In this case you need to apply GUID attribute.

Example

Class that is exported to COM with a fixed GUID


[GuidAttribute("bd2d60fa-8e40-4d06-ad6f-8760983efe33")]
public class ExposedToComClass
{
          
}