unable to load the native components of sql server compact corresponding to the ado.net

This is a very stupid exception, which is due to SQL CE has mismatched binaries.

So, just uninstall SQL Server Compact 32 bit (64 bit as well for 64 bit machines) from Add/Remove Programs

Download sql server compact edition and install them.

When you want to import dll

using System.Runtime.InteropServices;//DLLimport

[DllImport("winmm.dll", SetLastError = true)]

How special var is in C#, var can't be the type of property of class C#

var is static typed - the compiler and runtime know the type - they just save you some typing... the following are 100% identical:

var s = "abc";
Console.WriteLine(s.Length);

and

string s = "abc";
Console.WriteLine(s.Length);

Finding an ancestor and children of a WPF dependency object

Below are from : http://www.hardcodet.net/2008/02/find-wpf-parent

This is a simple snippet which helps you to find a specified parent of a given WPF dependency object somewhere in its visual tree:

(Snippet updated 2009.09.14)

/// <summary>
/// Finds a parent of a given item on the visual tree.
/// </summary>
/// <typeparam name="T">The type of the queried item.</typeparam>
/// <param name="child">A direct or indirect child of the
/// queried item.</param>
/// <returns>The first parent item that matches the submitted
/// type parameter. If not matching item can be found, a null
/// reference is being returned.</returns>
public static T TryFindParent<T>(this DependencyObject child)
    where T : DependencyObject
{

C# Invoke particular EventHandler in InvocationList

I am trying to get particular EventHandler get fired.

Event ProjectChanged was hooked by several EventHandlers

public static event EventHandler ProjectChanged;

foreach (var eventHandler in ProjectChanged.GetInvocationList())

{

    if (eventHandler.Method.Name == "UserContext_ProjectChanged")

    {

        eventHandler.DynamicInvoke(null,null);

    }

}

String to Guid in C#

public static Guid StringToGUID(string value)

{

    // Create a new instance of the MD5CryptoServiceProvider object.

    MD5 md5Hasher = MD5.Create();

    // Convert the input string to a byte array and compute the hash.

    byte[] data = md5Hasher.ComputeHash(Encoding.Default.GetBytes(value));

    return new Guid(data);

}

WPF GridViewColumn Width 100 percent

<local:ListViewEx.View>

    <GridView ColumnHeaderContainerStyle="{StaticResource CustomHeaderStyle}">

        <GridViewColumn Header="xxx" 
             Width="{Binding RelativeSource={RelativeSource FindAncestor, 
             AncestorType=ListView}, Path=ActualWidth}">

             <GridViewColumn.CellTemplate>

JumpList in Taskbar WPF, eg: recent items

http://msdn.microsoft.com/en-us/library/ff770767.aspx

Icon Render WPF

RenderOptions.BitmapScalingMode="NearestNeighbor"                            RenderOptions.EdgeMode="Aliased"

Text Trimming and ToolTip bind to itself

TextTrimming="CharacterEllipsis" TextWrapping="Wrap" ToolTip="{Binding Text, RelativeSource={RelativeSource Mode=Self}}

Autumn of Agile Screencast Series

Guys
http://www.autumnofagile.net/
this is very interesting & easy to understand agile video
--vishal

Cool stuff in .NET 4.0: System.Threading.Tasks.TaskScheduler

private void Save()

{

    System.Threading.Tasks.TaskScheduler uiScheduler = System.Threading.Tasks.TaskScheduler.FromCurrentSynchronizationContext();

    System.Threading.Tasks.Task<ErrorEnum>.Factory.StartNew(() =>

    {

        ErrorEnum callResult = ErrorEnum.OK;

        try

        {

            IsIdle = false;

            callResult = (ErrorEnum)DataContext.DomainRepository.SaveDomain(_domain);

            if (callResult != ErrorEnum.OK)

            {

                // If remote saving fails, rollback all the changes

                Rollback();

            }

            else

            {

                // If remote saving succeeds, save changes to local db

                SaveChangesToLocalDB();

            }

            return callResult;

        }

        catch (Exception ex)

        {

            LogManager.AddCMEventLog("DomainSettingsViewModel.Save", ex);

            // If anything goes wrong, rollback all the changes

            return ErrorEnum.LocalFatalAnonymousError;

        }

        finally

        {

            IsIdle = true;

        }

    }).ContinueWith(task => ShowResult(task.Result), uiScheduler);

}




This running tasks in background thread, then call UI thread to execute the ShowResult() function, Just like UIDispatcher

Set Window on top of others

The correct way to implement a modal window is by setting  this.Owner = Application.Current.MainWindow; in the XAML, and show the dialog by using DialogName.ShowDialog();

TextTrimming ToolTip in WPF

<TextBlock Text="{Binding State}" TextTrimming="CharacterEllipsis" Foreground="#6D6D6D"
                                                           ToolTip="{Binding Text, RelativeSource={RelativeSource Mode=Self}}"/>

C# Write Access Check

        /// <summary> Checks for write access for the given file.

        /// </summary>

        /// <param name="fileName">The filename.</param>

        /// <returns>true, if write access is allowed, otherwise false</returns>

        public static bool WriteAccess(string dire)

        {

            // Get the access rules of the specified files (user groups and user names that have access to the file)

            var rules = Directory.GetAccessControl(dire).GetAccessRules(true, true, typeof(System.Security.Principal.SecurityIdentifier));

            // Get the identity of the current user and the groups that the user is in.

            var groups = WindowsIdentity.GetCurrent().Groups;

            string sidCurrentUser = WindowsIdentity.GetCurrent().User.Value;

            // Check if writing to the file is explicitly denied for this user or a group the user is in.

            if (rules.OfType<FileSystemAccessRule>().Any(r => (groups.Contains(r.IdentityReference) || r.IdentityReference.Value == sidCurrentUser) && r.AccessControlType == AccessControlType.Deny && (r.FileSystemRights & FileSystemRights.WriteData) == FileSystemRights.WriteData))

                return false;

            // Check if writing is allowed

            return rules.OfType<FileSystemAccessRule>().Any(r => (groups.Contains(r.IdentityReference) || r.IdentityReference.Value == sidCurrentUser) && r.AccessControlType == AccessControlType.Allow && (r.FileSystemRights & FileSystemRights.WriteData) == FileSystemRights.WriteData);

        }

WPF Mouse Cursors busy

Mouse.OverrideCursor = Cursors.Wait;

Mouse.OverrideCursor = null;

Articles to read about Threads

http://msdn.microsoft.com/en-us/magazine/cc163328.aspx

http://msdn.microsoft.com/en-us/library/ms741870.aspx

Use the "using" C# key word to build sql connection

While reviewing some C# code written by a newbie programmer and buddy of mine, I noticed a lack of calling Dispose() on SqlConnection and SqlCommand objects. And in all cases, the database code was not placed in try / finally blocks. This is typical newbie style of development that everyone, including myself, attempted in the very beginning.

SqlConnection cn = new SqlConnection(connectionString);
SqlCommand cm = new SqlCommand(commandString, cn);

Set "Auto" to GridView Colum Width when re-binding data to the GridView

The GridView Colum Width is a headache.

detailView.Columns.OfType<System.Windows.Controls.GridViewColumn>().ToList().ForEach(c => c.Width = c.ActualWidth);

detailView.Columns.OfType<System.Windows.Controls.GridViewColumn>().ToList().ForEach(c => c.Width = Double.NaN);


http://msdn.microsoft.com/en-us/library/system.windows.controls.gridviewcolumn.width.aspx

Double.NaN means auto-size

WPF Make a Button invoked by Enter Key, set it as IsDefault=true

In the window, I try to use focus manager to set the button focused to invoke Enter Key, but the focus may lost.

By setting the IsDefault property, problem solved.

public void EnableFinish()

{

    btnNext.Visibility = Visibility.Hidden;

    btnFinish.Visibility = Visibility.Visible;

    btnFinish.IsDefault = true;

}