Enumeration in C#.Net

It is a Special format of Value Type.
Inherited from System.Enum Class.
Consists of some underlying data type.
All members in an enum are Public members.
How to create enumeration?

enum Family
{
Father, Mother, Son, Daughter
}

How to use enum keyword in C#.net Program?
Create a Project in the VS 2008 using C# language.
Open you form Code view.
Copy and Paste this Code with Class.

enum Company
{
IBM,
GANTEC,
INTEL,
HP
}

Here ,Company is name of the enum.
Now we will call enum value in the form loading event.
I want to display a value of enum value using MessageBox.
So declare a MessageBox.Show(“”) in the foem Load event.

MessageBox.Show(Company.GANTEC.ToString());

Please note this we use ToString() Method .Why we use this?Because MessageBox show method Parameter is string.you can use differennt way.

MessageBox.Show(Convert.ToString(Company.GANTEC));
Or
string str = Company.GANTEC.ToString();
MessageBox.Show(str);

It depends upon user choice.
How to get Integer value from enum?

enum Company
{
IBM =1,
GANTEC,
INTEL,
HP
}

In this example , I declared value for IBM.now, I want to display a integer value from enum.So I used below code in the Load Event.

int i = (int)Company.GANTEC;
MessageBox.Show(i.ToString());

User can view 2. we intialized first Value of enum is 1.So automatically,enum add a values.SO we get 2.Suppose ,user uses this way.

enum Company.
{
IBM =1,
KRISH,
GANTEC=1,
INTEL,
HP
}
int i = (int)Company.IBM;
MessageBox.Show(i.ToString());
int i = (int)Company. INTEL;
MessageBox.Show(i.ToString());

User will get 1 for IBM and 2 for INTEL.
Some useful Tips :
We can give same values to two enum members.
The values of enum cannot be changed
An enum cannot have tow members with same name.
We can’t inherit from enums.

Disable MessageBox Close button [x] in C#.Net

This is code for disable MessageBox Close button using C#.net

MessageBox.Show("Are you sure, Do you want to Close this Application?","Application Name",MessageBoxButtons.YesNo);

internal const int SC_CLOSE = 0xF060;
internal const int MF_GRAYED = 0x1;
internal const int MF_ENABLED = 0x00000000; //enabled button status
internal const int MF_DISABLED = 0x00000002; //disabled button status
[DllImport("user32.dll")]
private static extern IntPtr GetSystemMenu(IntPtr HWNDValue, bool Revert);
[DllImport("user32.dll")]
private static extern int EnableMenuItem(IntPtr tMenu, int targetItem, int targetStatus);

Read and Add a Key and Value into Application Configuration file using C#.net

I am creating a Method for Read and Add a Key and Value into Application Configuration file using C#.net.So you call that method in your program(where you want)
Read and Display an Application Configuration file using C#.net

public static void ShowConfigsetting()
{
foreach (string key in ConfigurationManager.AppSettings)
{
string value = ConfigurationManager.AppSettings[key];
string result = "Keys :" + " " + key + " " + "Key value:" + " " + value;
MessageBox.Show(result);
}
}

Add a Key and Value into Application Configuration file using C#.net

public static void AddintoConfigsetting(string appkeys,string appvalues)
{
Configuration config = ConfigurationManager.OpenExeConfiguration(ConfigurationUserLevel.None);
config.AppSettings.Settings.Add(appkeys, appvalues);
config.Save(ConfigurationSaveMode.Modified);
ConfigurationManager.RefreshSection("appSetting");
ShowConfigsetting();
}