Updating any Object through Linq Query

public class TestClass

{

    public String RollNo { get; set; }

    public String Name { get; set; }

    public String ClassName { get; set; }

}

ObservableCollection<TestClass> aaa = new ObservableCollection<TestClass>();

aaa.Add(new TestClass() {

RollNo = "1602", Name = "Khalid Rafique", ClassName = "A" });

aaa.Add(new TestClass() {

RollNo = "1702", Name = "Jamal Ali Khan", ClassName = "A" });

Method1

var result = aaa.Where(c => c.RollNo == "1702");

foreach (TestClass tc in result)

{

tc.Name = textBox4.Text;

      tc.ClassName = textBox1.Text;

}

Method2

aaa

    .Where(c => c.RollNo == "1702")

    .Update(m =>

                {

                  m.Name = textBox4.Text;

                  m.ClassName = textBox1.Text;

                });

Following is the class having extensible Method of Linq update.

public static class LinqExtensableMethods

{

public static void Update(this IEnumerable source, params Action[] updates)

{

    if (source == null)

      throw new ArgumentNullException("source");

    if (updates == null)

      throw new ArgumentNullException("updates");

       foreach (T item in source)

       {

                foreach (Action update in updates)

                {

                    update(item);

                }

       }

   }

}

Method3

var result =  ocTextClass .Where(c => c.RollNo == "1702").ToList().ForEach(tc => tc.Name=TextBox.Text);

Creating Cut, Copy, Paste Context menu for all textboxs in silverlight using Style in App.xaml

This article will provide you the help for creating Cut, Copy, Paste Context menu for all textboxs in silverlight using Style in App.xaml. This style will work for every Textbox that you will add in any form of your application..

App.xaml

xmlns:my="clr-namespace:YourApplicationNameSpace"

<Application.Resources>

  <Style TargetType="TextBox">

     <Setter Property="my:ControlCustomBehaviors.SetMenu" Value="true" />

  Style>

Application.Resources>

ControlCustomBehaviors.cs

using System;

using System.Net;

using System.Windows;

using System.Windows.Controls;

using System.Windows.Documents;

using System.Windows.Ink;

using System.Windows.Input;

using System.Windows.Media;

using System.Windows.Media.Animation;

using System.Windows.Shapes;

using System.Windows.Interactivity;

namespace YourApplicationNameSpace

{

public class ControlCustomBehaviors : Behavior<Control>

{

#region Set Context Menu

public static DependencyProperty SetMenuProperty =

          DependencyProperty.RegisterAttached("SetMenu",

                                              typeof(object),

                                              typeof(ControlCustomBehaviors),                                            new PropertyMetadata(null, SetMenuProp));

       

private static TextBox tBox;

private static void SetMenuProp(DependencyObject d, DependencyPropertyChangedEventArgs e)

{

 tBox = d as TextBox;

 CreateMenu();

 tBox.MouseRightButtonDown += new    MouseButtonEventHandler(AssociatedObject_MouseRightButtonDown);

 tBox.MouseRightButtonUp += new MouseButtonEventHandler(AssociatedObject_MouseRightButtonUp);

 tBox.SetValue(ContextMenuService.ContextMenuProperty, _contextMenu);

}

public static object GetSetMenu(UIElement obj)

{

    return (object)obj.GetValue(SetMenuProperty);

}

public static void SetSetMenu(DependencyObject obj, object txtbox)

{

     obj.SetValue(SetMenuProperty, txtbox);

}

private static ContextMenu _contextMenu;

private static MenuItem _copy;

private static MenuItem _cut;

private static MenuItem _paste;

private static void CreateMenu()

{

  _contextMenu = new ContextMenu();

  _cut = new MenuItem();

  _cut.Header = "Cut";

  _cut.Click += new RoutedEventHandler(cut_Click);

  _contextMenu.Items.Add(_cut);

  _copy = new MenuItem();

  _copy.Header = "Copy";

  _copy.Click += new RoutedEventHandler(copy_Click);

  _contextMenu.Items.Add(_copy);

   _paste = new MenuItem();

   _paste.Header = "Paste";

   _paste.Click += new RoutedEventHandler(paste_Click);

   _contextMenu.Items.Add(_paste);

  }

  static void paste_Click(object sen, RoutedEventArgs e)

  {

    tBox.SelectedText = Clipboard.GetText();

    _contextMenu.IsOpen = false;

     tBox.Focus();

  }

  static void cut_Click(object sen, RoutedEventArgs e)

  {

     Clipboard.SetText(tBox.SelectedText);

     tBox.SelectedText = string.Empty;

     _contextMenu.IsOpen = false;

     tBox.Focus();

  }

  static void copy_Click(object sen, RoutedEventArgs e)

  {

      Clipboard.SetText(tBox.SelectedText);

      _contextMenu.IsOpen = false;

      tBox.Focus();

  }

  static void AssociatedObject_MouseRightButtonUp(object Sender,  MouseButtonEventArgs e)

        {

  if (Clipboard.ContainsText() && tBox.IsReadOnly == false && tBox.IsEnabled == true)

  {

     _paste.IsEnabled = true;

  }

  else

  {

   _paste.IsEnabled = false;

  }

  if (string.IsNullOrEmpty(tBox.SelectedText))

  {

    _cut.IsEnabled = false;

    _copy.IsEnabled = false;

  }

  else

  {

    _cut.IsEnabled = true;

    _copy.IsEnabled = true;

  }

  _contextMenu.IsOpen = true;

   tBox.Focus();

  }

  static void AssociatedObject_MouseRightButtonDown(object sender, MouseButtonEventArgs e)

 {

    tBox = sender as TextBox;

    e.Handled = true;

 }

 #endregion

}

}

How to find the nth Highest Salary from Employee Table

You can find out the nth Highest Salary from the Employee Table by using following systax

select top 1 * from testEmp
where Emp_Id not in
(select top (n-1) Emp_Id from testEmp order by salary desc)
order by salary desc

Let Suppose following is you table

Emp_Id	Employee_Name	Salary
1602	Khalid Rafique	40000
1650	Jamal Ali Khan	45000
1530	Farhan Khan	29000
1533	Abid sultan	33000
1535	Atiq Khan	38000
1730	Rashid Ali	21000

if you want to find 2nd highest salary, you need to have to write the following query

select top 1 * from testEmp 
where Emp_Id not in
(select top (2-1) Emp_Id from testEmp order by salary desc)
order by salary desc

Result:

Emp_Id	Employee_Name	Salary
1602	Khalid Rafique	40000

if you want to find 3rd highest salary, you need to have to write the following query

select top 1 * from testEmp 
where Emp_Id not in
(select top (3-1) Emp_Id from testEmp order by salary desc)
order by salary desc

Result:

Emp_Id	Employee_Name	Salary
1535	Atiq Khan	38000

if you want to find 4rd highest salary, you need to have to write the following query

select top 1 * from testEmp 
where Emp_Id not in
(select top (4-1) Emp_Id from testEmp order by salary desc)
order by salary desc

Result:

Emp_Id	Employee_Name	Salary
1533	Abid sultan	33000

How to find the dupliate record in sql w.r.t columns

You can find the duplicate record using the folloing query with respect to columns sal and age
if you have Users table

LoginId	Password	UserName	Sal	Age
admin	1153291460	Khalid Rafique	1100.00000000	25
asdf	tyro1	aa	1200.00000000	28
tyro	tyro1	Test Account	1200.00000000	28
tyro23	tyro1	Test Account	1200.00000000	28

One Way

select u1.* from Users u1 
inner join
  (select Sal, Age,COUNT(*)as [Count] from Users

   group by Sal,Age
   having COUNT(*)>1) 
as t1
on u1.Sal = t1.Sal and u1.Age =t1.Age

2nd Way

select * from Users
where CAST(Sal as varchar)+'-'+CAST(Age as varchar) in
(select CAST(Sal as varchar)+'-'+CAST(Age as varchar) from Users
 group by Sal,Age
 having COUNT(*)>1)

following will be the result of Query:

LoginId	Password	UserName	Sal	Age
asdf	tyro1	aa	1200.00000000	28
tyro	tyro1	Test Account	1200.00000000	28
tyro23	tyro1	Test Account	1200.00000000	28

How to create own Grid property binder class in silver light

    
public static class GridPropertyBinder
{
  #region Visibility
  public static readonly DependencyProperty VisibilityBindingProperty = 
            DependencyProperty.RegisterAttached(
                                                "VisibilityBinding",
                                                typeof(object),
                                                typeof(GridPropertyBinder),
                                                new PropertyMetadata(null,
GridPropertyBinder.VisibilityBinding_PropertyChanged));

  public static object GetVisibilityBinding(DependencyObject source)
  {
     return (object)source.GetValue(GridPropertyBinder.VisibilityBindingProperty);
  }
  public static void SetVisibilityBinding(DependencyObject target, 
                                          object value)
  {
     target.SetValue(GridPropertyBinder.VisibilityBindingProperty, value);
  }
  private static void VisibilityBinding_PropertyChanged(DependencyObject d, 
                                                        DependencyPropertyChangedEventArgs e)
  {
     DataGridColumn column = d as DataGridColumn;
     if (column == null) { return; }
     if ((bool)e.NewValue)
     {
       column.Visibility = Visibility.Visible;
     }
     else
     {
        column.Visibility = Visibility.Collapsed;
     }
  }
  #endregion
}