Welcome To Asp. Net

MVC Dropdown List using Enumerator(enum)

In this post I will explain how to create a drop down list with Enumerator using MVC Rozar view. Many ways we have to do that but I will explain one of the easiest ways. If you follow this way we easily set select index of dropdown in Edit page also.

The view is

@{
var EnumInterval = from EnumDropDown().Interval n in Enum.GetValues(typeof(EnumDropDown.Interval))
select new SelectListItem
{
Value = n.ToString(),
Text = EnumDropDown.GetEnumDescription(n),
};
}

The Helper class is look like below

using System.Reflection;
using System.ComponentModel;
namespace EnumHtmlHelper.Helper
{
public static class EnumDropDown
{
public static string GetEnumDescription(TEnum value)
{
FieldInfo fi = value.GetType().GetField(value.ToString());
DescriptionAttribute[] attributes = (DescriptionAttribute[])fi.
GetCustomAttributes(typeof(DescriptionAttribute), false);
if ((attributes != null) && (attributes.Length > 0))
return attributes[0].Description;
else
return value.ToString();
}
public enum Interval
{
[Description("Daily")]
D = 1,
[Description("Quick")]
Q = 2,
[Description("Weekly")]
W = 3
}
}
}

The View source look like bellow

Method Overriding in C#.NET

Creating a method in derived class with same signature as a method in base class is called as method overriding.

Same signature means methods must have same name, same number of arguments and same type of arguments.
Method overriding is possible only in derived classes, but not within the same class.
When derived class needs a method with same signature as in base class, but wants to execute different code than provided by base class then method overriding will be used.
To allow the derived class to override a method of the base class, C# provides two options,virtual methods and abstract methods.

Page.PreviousPage Property(How to get value of previous page control value

When you use the Server.Transfer method or use cross-page posting to transfer processing from one ASP.NET page to another Page, the originating page contains request information that might be required for the destination page. You can use the Previous Page property to access that information.

The following example is in two parts. The first is an ASP.NET page that uses the Transfer method, exposed in the page model as Server.Transfer("path"). The second part is the target page, which uses the PreviousPage property to get the title of the first page.

<%@ Page Language="C#" %>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"

"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">

protected void Page_Load(object sender, EventArgs e)

{

// If second is an even number, the server is available

// Replace this line with a valid check for the server.

bool IsServerAvailable = (DateTime.Now.Second % 2 == 0);

if (!IsServerAvailable)

Server.Transfer("Notify.aspx", true);

}

</script>

<title>Switch Page</title>

</head>

<body>

<div>

<h2>Database Server is Available</h2>

<p>This page appears if the database server

is available.</p>

<p>Enter a pretend Server Name:

<asp:TextBox ID="serverNameText"

runat="server">MyDatabaseServer</asp:TextBox>

</p>

<p><asp:Button ID="SubmitButton" runat="server"

Text="Is server available?" /></p>

</div>

</form>

</body>

</html>

Notify.aspx page

<%@ Page Language="C#" %>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"

"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">

protected void Page_Load(object sender, EventArgs e)

{

// Find the server name on the previous page

TextBox txt =

(TextBox)Page.PreviousPage.FindControl("serverNameText");

if (txt != null)

prevServerName.Text = Server.HtmlEncode(txt.Text);

else

prevServerName.Text = "[Name Not available]";

}

</script>

</head>

<body>

<div>

<h2>Database Server is Not Available</h2>

<p>This page appears if the named database server is not

available, but the URL displays as the main target page.</p>

<p>Server Name (From Page.PreviousPage):

<asp:Label ID="prevServerName" runat="server" /></p>

<p>Refresh the page to see if the server is now available.</p>

</div>

</form>

</body>

</html>

A circular reference was detected while serializing an object of type 'System.Data.Entity.DynamicProxies

In this post I will explain Circular Reference Serialization Error in MVC Entity frame work. In my latest project I need to get data from database for purpose of Autocomplete.So I need data as JSON format.

When I request the “http://localhost:xxxx/Student/GetStudentJson”

Circular reference

How to get MVC Razor view Controls ID from Java script

In this post I will explain How to get MVC Razor view controller id from JavaScript .In real time some time we need to assign value to controller or we need to read (get) value from controller.

Example The view have Following Controller

@model MvcApplication1.Models.User

ViewBag.Title = "create";

}

<h2>

create</h2>

@using (Html.BeginForm())

{

@Html.ValidationSummary(true)

@Html.LabelFor(model => model.UserName)

</div>

MVC Action Names & NonAction method

In MVC URLs not being case sensitive. So that for example if you have the request “Home/About” this goes to HomeController and About action, as well as hOmE/AbOUT is going to the same controller and same action method.
SUPPOSE if we have 2 about action methods in the same controller with different cases such as:

public class HomeController:Controller{

public ViewResult About() {

return View();

}

public ViewResult aBOut()

{

return View();

}

when Icall action method About using following url http://your applicationname/Index/ABOUT I got following server page error

The framework can’t determine which ‘about’ function to call, and throws the exception telling that the call is ambiguous. Of course one way to fix this problem is to change the action name. If for some reason you don’t want to change the action name, and one of these function is not an action, then you can decorate this non action method with NonAction attribute. Example:

[NonAction]

public ActionResult aBOut()

{

return View();

}

JSON serialization error [maxJsonLength property.]

In my previous project I need to retrieve ticket from Web service.When I request the web service it return a ticket as JSON format.Some time I need to retrieve more than 10 lacks ticket per requet.In that time I got the following error

Exception information:
Exception type: InvalidOperationException
Exception message: Error during serialization or deserialization using the JSON JavaScriptSerializer. The length of the string exceeds the value set on the maxJsonLength property.

Solution is

We need to set Maximum allowed length of json response in Web.config file

The MaxJsonLength property cannot be unlimited, is an integer property that defaults to 102400 (100k).

It is good to check when was your last backup happened, I have wrote small query which it pull the information from msdb backupset table, it lists all the database names with last backup date and time.
It is very easy to track when was your last backup was happened. You can use the following query.

Create a Foreign Key relationship using Code First Entity Framework In asp.net MVC4

In this post I will explain How to create Foreign Key relationship in Entity Framework(EF).

When you create a model of relation database some time we got following error

Unable to retrieve association information for association 'Models.Product_Parent'. Only models that include foreign key information are supported. See Entity Framework documentation for details on creating models that include foreign key information.

I will explain how to create Model class for following relation data base

Login failed for user "sa" error 18456

In SQL Server's most common issue in securities is login failed for user, Error 18456.
To resolve 18456 error, you have to change the Server Authentication mode "SQL Server and Windows Authentication mode".

In order to resolve the above issue through selecting "SQL Server and Windows Authentication mode", please refer to the following steps:
Here is the error #18456 getting while connecting to the server through "SA" login and password.

Welcome To Asp. Net

Labels

MVC Dropdown List using Enumerator(enum)

Method Overriding in C#.NET

Page.PreviousPage Property(How to get value of previous page control value

A circular reference was detected while serializing an object of type 'System.Data.Entity.DynamicProxies

How to get MVC Razor view Controls ID from Java script

MVC Action Names & NonAction method

JSON serialization error [maxJsonLength property.]

HOW TO CHECK YOUR LAST SQL DATABASE BACKUP TIME

Create a Foreign Key relationship using Code First Entity Framework In asp.net MVC4

Login failed for user "sa" error 18456