Search This Blog

Tuesday, April 8, 2014

Days In Month C# Example

C# > System Namespace > DateTime > DaysInMonth 

Returns the number of days in the specified year and month.

Example

int daysInMonth = System.DateTime.DaysInMonth(2014, 4);




Friday, March 28, 2014

ASP.NET System Web UI HtmlControls

ASP.NET > System.Web.UI.HtmlControls

Contains classes that allow you to create HTML server controls on a Web Forms page, so it allows you to programmatically control the HTML elements on a Web Forms page.





Create dynamic table runtime ASP.NET

ASP.NET > System.Web.UI.HtmlControls > HtmlTable 

HtmlTable allows programmatic access on the server to the HTML
element.


Example: Create dynamic table runtime ASP.NET

HTML:

<%@ Page Language="C#" AutoEventWireup="true" CodeBehind="WebForm1.aspx.cs" Inherits="WebApplication2.WebForm1" %>

<!DOCTYPE html>

<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
    <title></title>
</head>
<body>
    <form id="form1" runat="server">
    <div>
   
        <asp:Panel ID="Panel1" runat="server">
        </asp:Panel>
   
    </div>
    </form>
</body>
</html>






Code:

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.HtmlControls;
using System.Web.UI.WebControls;

namespace WebApplication2
{
    public partial class WebForm1 : System.Web.UI.Page
    {
        protected void Page_Load(object sender, EventArgs e)
        {
            HtmlTable dTable = new HtmlTable();
            dTable.Border = 1;
            int tRow; 
            int tCell; 
            for (tRow = 0; tRow < 10; tRow++) 
            { 
                HtmlTableRow dTRow = new HtmlTableRow(); 
                for (tCell = 0; tCell < 5; tCell++) 
                { 
                    HtmlTableCell dTCell = new HtmlTableCell(); 
                    dTCell.InnerText = "Row: " + Convert.ToString(tRow + 1) + " Col: " + Convert.ToString(tCell + 1); 
                    dTRow.Controls.Add(dTCell); 
                } 
                dTable.Controls.Add(dTRow); 
            } 
            Panel1.Controls.Add(dTable); 

        }
    }
}




C# Keywords

C# > Keywords

Keywords are reserved identifiers used by compiler. 


  • cannot be used as identifiers in your program unless they include @ as a prefix (@then is a valid identifier)
  • contextual keywords have special meaning only in a limited program context and can be used as identifiers outside that context
Literal keywords
    Access keywords
      Access modifiers
      Operator
        Method
        Contextual









        Null keyword C#

        C# > Keywords > Null

        Null represent reference that does not refer to any object.
        • default value of reference type variables
        • ordinary value types cannot be null

        Example

        using System;
        using System.Collections.Generic;
        using System.ComponentModel;
        using System.Data;
        using System.Drawing;
        using System.Linq;
        using System.Text;
        using System.Threading.Tasks;
        using System.Windows.Forms;

        namespace WindowsFormsApplication2
        {
            public class TestClass
            {
                public void TestMethod() { }
            }

            public partial class Form1 : Form
            {
                public Form1()
                {
                    InitializeComponent();
                }

                private void Form1_Load(object sender, EventArgs e)
                {
                   
                    TestClass tc=null;

                    tc = new TestClass();
                    tc.TestMethod();   // You can call TestMethod method.

                    tc = null; // set tc to null => the object is no longer accessible and can now be garbage collected
                   
                    string s1 = null;

                    //int k = null; // Error Cannot convert null to 'int' because it is a non-nullable value type  

                    int? k = null; // use a nullable value type instead OK

                }
            }
        }










        Tuesday, March 25, 2014

        Filter with LINQ DataTable C#

        C# > System.Data   > DataTable > Filter with LINQ

        Example:


        DataTable dt = new DataTable("table");
        dt.Columns.Add("id", Type.GetType("System.Int32"));
        dt.Columns.Add("name", Type.GetType("System.String"));

        DataRow dr = dt.NewRow();
        dr["id"] = 1;
        dr["name"] = "john";
        dt.Rows.Add(dr);

        dr = dt.NewRow();
        dr["id"] = 2;
        dr["name"] = "dan";
        dt.Rows.Add(dr);

        DataTable tbl = (from DataRow dr1 in dt.Rows
                             where dr1["id"].ToString() == "1"
                             select dr).CopyToDataTable();





        Friday, March 21, 2014

        DateValue Visual Basic Example

        VB.NET Functions > DateValue 

        Returns a date value containing the date information represented by a string.

        Example

        Dim dt As Date
        dt = DateValue("March 21, 2014")

        MessageBox.Show(dt)