Saturday, October 26, 2013

What is Microsoft ADO.NET Entity Framework

The Microsoft ADO.NET Entity Framework (EF) is an Object/Relational Mapping (ORM) framework that enables developers to work with relational data as domain-specific objects, eliminating the need for most of the data access plumbing code that developers usually need to write.

The Entity Framework works with Microsoft SQL Server and 3rd party databases through extended ADO.NET Data Providers, providing a common query language against different relational databases through either LINQ to Entities or Entity SQL.

Thursday, May 23, 2013

Set and Get Textbox Value inside ascx Control from ASP.NET Page

Setting and getting Textbox value inside user control (ascx control) from aspx page is a usual practice in both simple and complex projects.

In this tutorial, we will

Create New User Control.
Add User Control in aspx Page.
Set Textbox Value inside User Control
Get Textbox value From User Control

Create New User Control

Right Click on Project, Click Add New Item.
A pop up window will be opened.
Select Web User Control from list, change its Name to 'myControl' and click Add.
Two files will be added with name 'myControl.ascx' and 'myControl.ascx.cs'

Replace the code in 'myControl.ascx' file with following code.

<%@ Control Language="C#" AutoEventWireup="true" CodeFile="myControll.ascx.cs" Inherits="Controls_myControll" %>

<table>

<tr>

<td>

Name :

</td>

<td>

<asp:TextBox ID="txtName" runat="server"></asp:TextBox>

</td>

</tr>

<tr>

<td>

Age :

</td>

<td>

<asp:TextBox ID="txtAge" runat="server"></asp:TextBox>

</td>

</tr>

<tr>

<td>

Profession :

</td>

<td>

<asp:TextBox ID="txtProfession" runat="server"></asp:TextBox>

</td>

</tr>

</table>

Add following code in 'myControl.ascx.cs' File.

public string Name

{

get { return txtName.Text.ToString(); }

set { txtName.Text = value; }

}

public string Age

{

get { return txtAge.Text.ToString(); }

set { txtAge.Text = value; }

}

public string Profession

{

get { return txtProfession.Text.ToString(); }

set { txtProfession.Text = value; }

}

Add User Control in aspx Page

Create New aspx Page with name ‘PageForWebControl’.
Open Design View and drag and drop user control on it. Some code will be added in 'PageForWebControl.aspx' page automatically.

Page will look like this.

<%@ Page Language="C#" AutoEventWireup="true" CodeFile="PageForWebControl.aspx.cs" Inherits="PageForWebControl" %>

<%@ Register src="Controls/myControll.ascx" tagname="myControll" tagprefix="uc1" %>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">

</head>

<body>

<div>

<uc1:myControll ID="myControll1" runat="server" />

</div>

</form>

</body>

</html>

Set Textbox Value inside User Control

Add following code snippet in Page Load Event of 'PageForWebControl.aspx' page to set Values of Textbox inside User Control.

// Setting Values in ASCX Control

myControll1.Name = "Waqas Ali";

myControll1.Age = "24";

myControll1.Profession = "Computer Scientist";

Get Textbox value From User Control

Add following code snippet in Page Load Event of PageForWebControl.aspx page to get values of Textbox from User Control.

string _name = string.Empty;

int _age = 0;

string _profession = string.Empty;

// Getting Values from ASCX Control

_name = myControll1.Name;

_age = Convert.ToInt32(myControll1.Age);

_profession = myControll1.Profession;

Now you are all done. Run Project and test your values.

Wednesday, May 22, 2013

Difference Between string and String in C#.NET

There is no different between string and String (System.String). string is an alias for System.String in C#.Net.

They compile to the same code, so no difference at execution time. The complete list of aliases in C#.Net is

object:System.Object
string:System.String
bool:System.Boolean
byte:System.Byte
sbyte:System.SByte
short:System.Int16
ushort:System.UInt16
int:System.Int32
uint:System.UInt32
long:System.Int64
ulong:System.UInt64
float:System.Single
double:System.Double
decimal:System.Decimal
char:System.Char

Thursday, May 2, 2013

ORA-00254 Error in Archive Control String

Error Code
ORA-00254

Description
Error in archive control string 'string'.

Cause
Possible cause of this error is, the specified archive log location is invalid in the archive command or the LOG_ARCHIVE_DEST initialization parameter.

Action
To fix this issue, check the archive string used to make sure it refers to a valid online device.

reference

ORA-00253 Character Limit String Exceeded by Archive Destination

Error Code
ORA-00253

Description
Character limit string exceeded by archive destination string string.

Cause
Possible cause of this error is, the destination specified by an ALTER SYSTEM ARCHIVE LOG START TO command was too long.

Action
To fix this issue, retry the ALTER SYSTEM command using a string shorter than the limit specified in the error message.

reference