I am using an IDbCommandTreeInterceptor to enable soft deletes on my model.
System.Data.Entity.Infrastructure.Interception.DbInterception.Add(
new SoftDeleteInterception());
I want to be able to disable the interceptor temporarily so that I can select a "deleted" entity for auditing purposes.
However, It seems like the DbInterception collection is assembly-wide.
Is there any way to create a new DbContext without interception on?
Or even a way to add the interceptor to the DbContext every time it is created?
I have extended my db context class with additional property
[DbConfigurationType(typeof(DbConfig))]
public partial class YourEntitiesDB
{
public bool IgnoreSoftDelete { get; set; }
}
Then in the TreeCreated(...) method i check this flag and if true then it just doesn't go further to the QueryVisitor
public class SoftDeleteInterceptor : IDbCommandTreeInterceptor
{
public SoftDeleteInterceptor()
{
}
public void TreeCreated(DbCommandTreeInterceptionContext interceptionContext)
{
var db = interceptionContext.DbContexts.FirstOrDefault() as YourEntitiesDB;
if (db!=null && db.IgnoreSoftDelete)
{
// Ignore soft delete interseptor (Used in archives)
return;
}
if (interceptionContext.OriginalResult.DataSpace == DataSpace.CSpace)
{
var queryCommand = interceptionContext.Result as DbQueryCommandTree;
if (queryCommand != null)
{
var newQuery = queryCommand.Query.Accept(new SoftDeleteQueryVisitor());
interceptionContext.Result = new DbQueryCommandTree(
queryCommand.MetadataWorkspace,
queryCommand.DataSpace,
newQuery);
}
var deleteCommand = interceptionContext.OriginalResult as DbDeleteCommandTree;
if (deleteCommand != null)
{
var column = SoftDeleteAttribute.GetSoftDeleteColumnName(deleteCommand.Target.VariableType.EdmType);
if (column != null)
{
var setClauses = new List<DbModificationClause>();
var table = (EntityType)deleteCommand.Target.VariableType.EdmType;
if (table.Properties.Any(p => p.Name == column))
{
setClauses.Add(DbExpressionBuilder.SetClause(
DbExpressionBuilder.Property(
DbExpressionBuilder.Variable(deleteCommand.Target.VariableType, deleteCommand.Target.VariableName),
column),
DbExpression.FromBoolean(true)));
}
var update = new DbUpdateCommandTree(
deleteCommand.MetadataWorkspace,
deleteCommand.DataSpace,
deleteCommand.Target,
deleteCommand.Predicate,
setClauses.AsReadOnly(),
null);
interceptionContext.Result = update;
}
}
}
}
}
In order to use it i just set the flag to true when needed
YuorEntitiesDB DB = new YuorEntitiesDB();
DB.IgnoreSoftDelete = true;
DB.Records.Where(...)
Related
I have 3 Oracle databases; production, test, development. For the most part, they are all identical. In my application, I would like the changes to be applied to multiple databases. For example:
using (var context = new Context())
{
context.People.Add(new Person { name = "sean" });
context.SaveChanges();
}
I then tried to override the SaveChanges method and save to multiple databases by doing this:
public void SaveChanges(int auditPersonNumber)
{
OracleCredentials.Default.Server = "VDev";
base.SaveChanges();
OracleCredentials.Default.Server = "VTest";
base.SaveChanges();
OracleCredentials.Default.Server = "VProd";
base.SaveChanges();
}
This didn't work but should explain what I am trying to achieve.
I haven't yet used EntityFramework against an Oracle database, but it should be similar to connecting against SQL Server in that the database name is specified via a ConnectionString. Your project should have a config file (web.config, app.config, or if it's a .NET Core application it could be in appsettings.json) with that ConnectionString in it.
For example:
<add name="YourConnectionString" providerName="YourOracleProviderName" connectionString="User Id=test;Password=testpassword;Data Source=eftest" />
The DbContext base constructor accepts a string argument that specifies which ConnectionString it should use, and thus which database to connect to. If you look into your context class, the default constructor should call the base constructor with that argument.
public YourDbContext() : base("YourConnectionString") {}
In order to save to multiple databases you will need to work against different instances of DbContext each with a different ConnectionString argument. So, your config will need to list a few different connection strings for every Db and you'll probably want your DbContext class to allow the argument in its constructor as well.
Perhaps the SaveChanges method implementation could instantiate the other DbContexts you'd need to use:
public void SaveChanges(int auditPersonNumber)
{
using (var context = new Context("OtherConnectionString1"))
{
// apply same changes
context.SaveChanges();
}
using (var context = new Context("OtherConnectionString2"))
{
// apply same changes
context.SaveChanges();
}
base.SaveChanges();
}
As for the applying the same changes, I would expect you can read them out from the DbContext ChangeTracker. There's an explanation about that using EF Core here but in earlier versions it's similar: http://www.entityframeworktutorial.net/efcore/changetracker-in-ef-core.aspx
Also keep in mind that the SaveChanges call to OtherConnectionString1 could succeed while others could fail, so the data might be inconsistent in your different databases. You may have to look into using transactions across multiple databases but I haven't done this yet myself.
I was able to figure out a solution thanks to the help of Sangman.
public class Context : Shared.Data.Context
{
new public void SaveChanges(int auditPersonNumber)
{
var errors = string.Empty;
var testConnectionString = "ConnectionString";
var developmentConnectionString = "ConnectionString";
//Save to test database
if (SecurityMaintenanceUser.ApplyToTest)
errors = ApplyToDatabase(testConnectionString, auditPersonNumber, "Test");
if (!string.IsNullOrWhiteSpace(errors))
errors += "\n\n";
//Save to development database
if (SecurityMaintenanceUser.ApplyToDevelopment)
errors += ApplyToDatabase(developmentConnectionString, auditPersonNumber, "Development");
if (!string.IsNullOrWhiteSpace(errors))
MessageBox.Show(errors, "Error", MessageBoxButtons.OK, MessageBoxIcon.Error);
//Save to production database
base.SaveChanges(auditPersonNumber);
}
private string ApplyToDatabase(string connectionString, int auditPersonNumber, string server)
{
try
{
using (var context = new Context(connectionString))
{
context.Configuration.ValidateOnSaveEnabled = false;
foreach (var entry in ChangeTracker.Entries())
{
var dataSet = context.Set(entry.Entity.GetType());
if (entry.State == EntityState.Added)
{
dataSet.Add(entry.Entity);
}
else if (entry.State == EntityState.Deleted)
{
var contextEntity = dataSet.Find(GetPrimaryKeyValues(entry));
context.DeleteEntity(contextEntity, auditPersonNumber);
}
else if (entry.State == EntityState.Modified)
{
var contextEntity = dataSet.Find(GetPrimaryKeyValues(entry));
context.Entry(CopyProperties(entry.Entity, contextEntity)).State = EntityState.Modified;
}
}
context.SaveChanges(auditPersonNumber);
return string.Empty;
}
}
catch (Exception e)
{
return $"Failed to apply database changes to {server}.\n{e.GetFullMessage()}";
}
}
private object CopyProperties(object source, object destination)
{
if (source == null || destination == null)
throw new Exception("Source or/and Destination Objects are null");
var typeDest = destination.GetType();
var typeSrc = source.GetType();
foreach (var srcProp in typeSrc.GetProperties())
{
if (srcProp.Name == "Type" || srcProp.Name == "AuthenticationLog")
continue;
//This blocks any complex objects attached to the entity, will need to be changed for your application
if (srcProp.PropertyType.FullName.Contains("Library.Shared"))
continue;
if (!srcProp.CanRead)
continue;
var targetProperty = typeDest.GetProperty(srcProp.Name);
if (targetProperty == null)
continue;
if (!targetProperty.CanWrite)
continue;
if (targetProperty.GetSetMethod(true)?.IsPrivate == true)
continue;
if ((targetProperty.GetSetMethod().Attributes & MethodAttributes.Static) != 0)
continue;
if (!targetProperty.PropertyType.IsAssignableFrom(srcProp.PropertyType))
continue;
targetProperty.SetValue(destination, srcProp.GetValue(source, null), null);
}
return destination;
}
private object GetPrimaryKeyValues(DbEntityEntry entry)
{
var objectStateEntry = ((IObjectContextAdapter)this).ObjectContext.ObjectStateManager.GetObjectStateEntry(entry.Entity);
return objectStateEntry.EntityKey.EntityKeyValues[0].Value;
}
public static string GetFullMessage(this Exception ex)
{
return ex.InnerException == null ? ex.Message : $"{ex.Message}\n{ex.InnerException.GetFullMessage()}";
}
public static string Replace(this string source, string oldString, string newString, StringComparison comp)
{
int index = source.IndexOf(oldString, comp);
if (index >= 0)
{
source = source.Remove(index, oldString.Length);
source = source.Insert(index, newString);
}
if (source.IndexOf(oldString, comp) != -1)
source = Replace(source, oldString, newString, comp);
return source;
}
}
I cannot get updated item in ListView after modifying existing database item. Though, once I reload the application one can see updated item in ListView.
I have binded to an ObservableCollection for the ListView
This is my interface
public interface IService
{
IEnumerable<Employee> GetDetails();
IEnumerable<Employee> GetDetailsById(int MatchID);
}
I have implemented IService IEmployeeServiceData class.
public class IEmployeeServiceData:IService
{
private EmployeeContext Context
{
get;
set;
}
public IEmployeeServiceData()
{
Context = new EmployeeContext();
}
public IEnumerable<Model.Employee> GetDetails()
{
return Context.Employees;
}
public IEnumerable<Model.Employee> GetDetailsById(int MatchID)
{
var q = from f in Context.Employees
where f.EMPLOYEE_ID == MatchID
select f;
return q.AsEnumerable();
}
}
This is my VM
public void RefereshData()
{
var e = EmployeeService.GetDetails();
if (SelectedIndexValue == 1)
{
var Data = from e1 in e
where e1.LOCATION == "Pune"
select e1;
EmployeeMasterData = new ObservableCollection<Model.Employee>(Data);
}
else if(SelectedIndexValue==2)
{
var Data = from e1 in e
where e1.LOCATION == "Bangalore"
select e1;
EmployeeMasterData = new ObservableCollection<Model.Employee>(Data);
}
else
{
EmployeeMasterData = new ObservableCollection<Model.Employee>(e);
}
}
Updating Exiting Item:
public void UpdateEmployee()
{
try
{
Context = new EmployeeContext();
Employee Emp = Context.Employees.First(i => i.EMPLOYEE_ID == FindId1);
Emp.FIRST_NAME = this.FIRSTNAME;
Emp.FAMILY_NAME = this.FAMILY_NAME;
Emp.EXTERNAL_ID = this.EXTERNALID;
Emp.DB_SPONSOR = this.DBSPONSOR;
Emp.LEGAL_ENTITY = this.LEGAL_ENTITY;
Emp.COST_CENTER = this.COST_CENTER1;
Emp.STATUS = this.StatusCategory;
Emp.ENTRY_DATE = this.ENTRYDATE;
Emp.LOCATION = this.LocationCategory1;
Context.SaveChanges();
Clear();
AlertMessage1 = "Employee Record is Updated Sucessfulyy !!!";
IsVisible1 = true;
timer.Start();
}
catch(Exception ex)
{
Console.WriteLine(ex.InnerException);
}
}
Existing Item
Updated Item
Changes done to an entity in Entity Framework will not be reflected on screen because the two instances are not related in your example. Yes the have the same values, but they are two different distinct reference locations in memory. **For the ObservableCollection is a copy of the list and not the actual list being manipulated in your example.
Hence they are not related.
To show a change you have these options:
Change the actual object's property(ies) held by the observable collection to mirror the change done in to the other EF entity. Also the EF entity must adhere to INotifyPropertyChange or also the data property change won't be seen on the screen.
Or delete the screen entity and add the changed entity into the list.
Or delete the whole observable list and re-add it with the latest version from EF. (You mention that you do this and that is an option as well).
I am building a silverlight app for CRM 2011 and I was wondering what the best way to retrieve data from the CRM system is.
I have linked in my organisation as a service reference and am able to access that. I have seen a few different ways to retrieve data but they all seem rather complicated. Is there anything like what we can use in plugins such as a fetch XMl query or a simple Service.Retrieve method?
Thanks
If you add a service reference to your project you can use LINQ to query the datasets.
You can download the CSDL from Developer Resources under the customisation area.
private FelineSoftContext context;
private System.String serverUrl;
private DataServiceCollection<SalesOrder> _orders;
public MainPage()
{
InitializeComponent();
serverUrl = (String)GetContext().Invoke("getServerUrl");
//Remove the trailing forward slash returned by CRM Online
//So that it is always consistent with CRM On Premises
if (serverUrl.EndsWith("/"))
serverUrl = serverUrl.Substring(0, serverUrl.Length - 1);
Uri ODataUri = new Uri(serverUrl + "/xrmservices/2011/organizationdata.svc/", UriKind.Absolute);
context = new FelineSoftContext(ODataUri) { IgnoreMissingProperties = true };
var orders = from ord in context.SalesOrderSet
orderby ord.Name
select new SalesOrder
{
Name = ord.Name,
SalesOrderId = ord.SalesOrderId
};
_orders = new DataServiceCollection<SalesOrder>();
_orders.LoadCompleted += _orders_LoadCompleted;
_orders.LoadAsync(orders);
}
void _orders_LoadCompleted(object sender, LoadCompletedEventArgs e)
{
if (e.Error == null)
{
if (_orders.Continuation != null)
{
_orders.LoadNextPartialSetAsync();
}
else
{
OrderLookup.ItemsSource = _orders;
OrderLookup.DisplayMemberPath = "Name";
OrderLookup.SelectedValuePath = "Id";
}
}
}
You will also need to add a method in your class as below:
private static ScriptObject GetContext()
{
ScriptObject xrmProperty = (ScriptObject)HtmlPage.Window.GetProperty("Xrm");
if (null == xrmProperty)
{
//It may be that the global context should be used
try
{
ScriptObject globalContext = (ScriptObject)HtmlPage.Window.Invoke("GetGlobalContext");
return globalContext;
}
catch (System.InvalidOperationException)
{
throw new InvalidOperationException("Property \"Xrm\" is null and the Global Context is not available.");
}
}
ScriptObject pageProperty = (ScriptObject)xrmProperty.GetProperty("Page");
if (null == pageProperty)
{
throw new InvalidOperationException("Property \"Xrm.Page\" is null");
}
ScriptObject contextProperty = (ScriptObject)pageProperty.GetProperty("context");
if (null == contextProperty)
{
throw new InvalidOperationException("Property \"Xrm.Page.context\" is null");
}
return contextProperty;
}
You will need to add an additional class library and put the following code within it. Change the class name to match the Context you exported:
partial class FelineSoftContext
{
#region Methods
partial void OnContextCreated()
{
this.ReadingEntity += this.OnReadingEntity;
this.WritingEntity += this.OnWritingEntity;
}
#endregion
#region Event Handlers
private void OnReadingEntity(object sender, ReadingWritingEntityEventArgs e)
{
ODataEntity entity = e.Entity as ODataEntity;
if (null == entity)
{
return;
}
entity.ClearChangedProperties();
}
private void OnWritingEntity(object sender, ReadingWritingEntityEventArgs e)
{
ODataEntity entity = e.Entity as ODataEntity;
if (null == entity)
{
return;
}
entity.RemoveUnchangedProperties(e.Data);
entity.ClearChangedProperties();
}
#endregion
}
public abstract class ODataEntity
{
private readonly Collection<string> ChangedProperties = new Collection<string>();
public ODataEntity()
{
EventInfo info = this.GetType().GetEvent("PropertyChanged");
if (null != info)
{
PropertyChangedEventHandler method = new PropertyChangedEventHandler(this.OnEntityPropertyChanged);
//Ensure that the method is not attached and reattach it
info.RemoveEventHandler(this, method);
info.AddEventHandler(this, method);
}
}
#region Methods
public void ClearChangedProperties()
{
this.ChangedProperties.Clear();
}
internal void RemoveUnchangedProperties(XElement element)
{
const string AtomNamespace = "http://www.w3.org/2005/Atom";
const string DataServicesNamespace = "http://schemas.microsoft.com/ado/2007/08/dataservices";
const string DataServicesMetadataNamespace = DataServicesNamespace + "/metadata";
if (null == element)
{
throw new ArgumentNullException("element");
}
List<XElement> properties = (from c in element.Elements(XName.Get("content", AtomNamespace)
).Elements(XName.Get("properties", DataServicesMetadataNamespace)).Elements()
select c).ToList();
foreach (XElement property in properties)
{
if (!this.ChangedProperties.Contains(property.Name.LocalName))
{
property.Remove();
}
}
}
private void OnEntityPropertyChanged(object sender, System.ComponentModel.PropertyChangedEventArgs e)
{
if (!this.ChangedProperties.Contains(e.PropertyName))
{
this.ChangedProperties.Add(e.PropertyName);
}
}
#endregion
}
I am will suggest you to use Silvercrmsoap , it's very easy to use. I have used this in my silverlight projects.
I want to create a database in ravendb , I used EnsureDatabaseExist() function. I am not able to use the function CreateDatabaseDocument() from namespace Raven.Client.Extensions and class is public static class MultiDatabase{} in my c# code. Intellisense in vs2010 not showing this function.
my code is :enter code here
public CreateDatabaseOpResult CreateDatabase(ConnectionOperationResult connection,string name)
{
DocumentDatabase database;
CreateDatabaseOpResult databaseOperationResult = new CreateDatabaseOpResult();
if (connection.IsOperationSuccessfull == true)
{
try
{
var doc = connection.documentStore.DatabaseCommands.ForDefaultDatabase();
var docId = doc.Get("Raven/Databases/" + name);
if (docId == null)
{
//static class
//multidatabase
connection.documentStore.DatabaseCommands.EnsureDatabaseExists(name);
}
else
{
databaseOperationResult.IsOperationSuccessfull = false;
throw new ArgumentException("Database already exists");
}
databaseOperationResult.IsOperationSuccessfull = true;
databaseOperationResult.database = database;
}
//and i want to use this function from
namespace Raven.Client.Extensions
{
///<summary>
/// Methods to create mutli tenants databases
///</summary>
public static class MultiDatabase
{
public static RavenJObject CreateDatabaseDocument(string name)
{
AssertValidName(name);
var doc = RavenJObject.FromObject(new DatabaseDocument
{
Settings =
{
{"Raven/DataDir", Path.Combine("~", Path.Combine("Tenants", name))}
}
});
doc.Remove("Id");
return doc;
}
thanks in advance...:)
CreateDatabase is an internal method which just returned the database document. EnsureDatabaseExist used this method and also stores that document if it doesn't exists.
You should use EnsureDatabaseExist method.
I want to filter a ObservableCollection with max 3000 items in a DataGrid with 6 columns. The user should be able to filter in an "&&"-way all 6 columns.
Should I use LINQ or a CollectionView for it? LINQ seemed faster trying some www samples. Do you have any pro/cons?
UPDATE:
private ObservableCollection<Material> _materialList;
private ObservableCollection<Material> _materialListInternal;
public MaterialBrowserListViewModel()
{
_materialListInternal = new ObservableCollection<Material>();
for (int i = 0; i < 2222; i++)
{
var mat = new Material()
{
Schoolday = DateTime.Now.Date,
Period = i,
DocumentName = "Excel Sheet" + i,
Keywords = "financial budget report",
SchoolclassCode = "1",
};
_materialListInternal.Add(mat);
var mat1 = new Material()
{
Schoolday = DateTime.Now.Date,
Period = i,
DocumentName = "Word Doc" + i,
Keywords = "Economical staticstics report",
SchoolclassCode = "2",
};
_materialListInternal.Add(mat1);
}
MaterialList = CollectionViewSource.GetDefaultView(MaterialListInternal);
MaterialList.Filter = new Predicate<object>(ContainsInFilter);
}
public bool ContainsInFilter(object item)
{
if (String.IsNullOrEmpty(FilterKeywords))
return true;
Material material = item as Material;
if (DocumentHelper.ContainsCaseInsensitive(material.Keywords,FilterKeywords,StringComparison.CurrentCultureIgnoreCase))
return true;
else
return false;
}
private string _filterKeywords;
public string FilterKeywords
{
get { return _filterKeywords; }
set
{
if (_filterKeywords == value)
return;
_filterKeywords = value;
this.RaisePropertyChanged("FilterKeywords");
MaterialList.Refresh();
}
}
public ICollectionView MaterialList { get; set; }
public ObservableCollection<Material> MaterialListInternal
{
get { return _materialListInternal; }
set
{
_materialListInternal = value;
this.RaisePropertyChanged("MaterialList");
}
}
Using ICollectionView gives you automatic collection changed notifications when you call Refresh. Using LINQ you'll need to fire your own change notifications when the filter needs to be re-run to update the UI. Not difficult, but requires a little more thought than just calling Refresh.
LINQ is more flexible that the simple yes/no filtering used by ICollectionView, but if you're not doing something complex there's not really any advantage to that flexibility.
As Henk stated, there shouldn't be a noticable performance difference in the UI.
For an interactive (DataGrid?) experience you should probabaly use the CollectionView. For a more code-oriented sorting, LINQ.
And with max 3000 items, speed should not be a (major) factor in a UI.
How about both? Thomas Levesque built a LINQ-enabled wrapper around ICollectionView.
Usage:
IEnumerable<Person> people;
// Using query comprehension
var query =
from p in people.ShapeView()
where p.Age >= 18
orderby p.LastName, p.FirstName
group p by p.Country;
query.Apply();
// Using extension methods
people.ShapeView()
.Where(p => p.Age >= 18)
.OrderBy(p => p.LastName)
.ThenBy(p => p.FirstName)
.Apply();
Code:
public static class CollectionViewShaper
{
public static CollectionViewShaper<TSource> ShapeView<TSource>(this IEnumerable<TSource> source)
{
var view = CollectionViewSource.GetDefaultView(source);
return new CollectionViewShaper<TSource>(view);
}
public static CollectionViewShaper<TSource> Shape<TSource>(this ICollectionView view)
{
return new CollectionViewShaper<TSource>(view);
}
}
public class CollectionViewShaper<TSource>
{
private readonly ICollectionView _view;
private Predicate<object> _filter;
private readonly List<SortDescription> _sortDescriptions = new List<SortDescription>();
private readonly List<GroupDescription> _groupDescriptions = new List<GroupDescription>();
public CollectionViewShaper(ICollectionView view)
{
if (view == null)
throw new ArgumentNullException("view");
_view = view;
_filter = view.Filter;
_sortDescriptions = view.SortDescriptions.ToList();
_groupDescriptions = view.GroupDescriptions.ToList();
}
public void Apply()
{
using (_view.DeferRefresh())
{
_view.Filter = _filter;
_view.SortDescriptions.Clear();
foreach (var s in _sortDescriptions)
{
_view.SortDescriptions.Add(s);
}
_view.GroupDescriptions.Clear();
foreach (var g in _groupDescriptions)
{
_view.GroupDescriptions.Add(g);
}
}
}
public CollectionViewShaper<TSource> ClearGrouping()
{
_groupDescriptions.Clear();
return this;
}
public CollectionViewShaper<TSource> ClearSort()
{
_sortDescriptions.Clear();
return this;
}
public CollectionViewShaper<TSource> ClearFilter()
{
_filter = null;
return this;
}
public CollectionViewShaper<TSource> ClearAll()
{
_filter = null;
_sortDescriptions.Clear();
_groupDescriptions.Clear();
return this;
}
public CollectionViewShaper<TSource> Where(Func<TSource, bool> predicate)
{
_filter = o => predicate((TSource)o);
return this;
}
public CollectionViewShaper<TSource> OrderBy<TKey>(Expression<Func<TSource, TKey>> keySelector)
{
return OrderBy(keySelector, true, ListSortDirection.Ascending);
}
public CollectionViewShaper<TSource> OrderByDescending<TKey>(Expression<Func<TSource, TKey>> keySelector)
{
return OrderBy(keySelector, true, ListSortDirection.Descending);
}
public CollectionViewShaper<TSource> ThenBy<TKey>(Expression<Func<TSource, TKey>> keySelector)
{
return OrderBy(keySelector, false, ListSortDirection.Ascending);
}
public CollectionViewShaper<TSource> ThenByDescending<TKey>(Expression<Func<TSource, TKey>> keySelector)
{
return OrderBy(keySelector, false, ListSortDirection.Descending);
}
private CollectionViewShaper<TSource> OrderBy<TKey>(Expression<Func<TSource, TKey>> keySelector, bool clear, ListSortDirection direction)
{
string path = GetPropertyPath(keySelector.Body);
if (clear)
_sortDescriptions.Clear();
_sortDescriptions.Add(new SortDescription(path, direction));
return this;
}
public CollectionViewShaper<TSource> GroupBy<TKey>(Expression<Func<TSource, TKey>> keySelector)
{
string path = GetPropertyPath(keySelector.Body);
_groupDescriptions.Add(new PropertyGroupDescription(path));
return this;
}
private static string GetPropertyPath(Expression expression)
{
var names = new Stack<string>();
var expr = expression;
while (expr != null && !(expr is ParameterExpression) && !(expr is ConstantExpression))
{
var memberExpr = expr as MemberExpression;
if (memberExpr == null)
throw new ArgumentException("The selector body must contain only property or field access expressions");
names.Push(memberExpr.Member.Name);
expr = memberExpr.Expression;
}
return String.Join(".", names.ToArray());
}
}
Credit:
http://www.thomaslevesque.com/2011/11/30/wpf-using-linq-to-shape-data-in-a-collectionview/
Based on a visual complexity and number of items there really WILL be a noticable performance difference since the Refresh method recreates the whole view!!!
You need my ObservableComputations library. Using this library you can code like this:
ObservableCollection<Material> MaterialList = MaterialListInternal.Filtering(m =>
String.IsNullOrEmpty(FilterKeywords)
|| DocumentHelper.ContainsCaseInsensitive(
material.Keywords, FilterKeywords, StringComparison.CurrentCultureIgnoreCase));
MaterialList reflects all the changes in the MaterialListInternal collection. Do not forget to add the implementation of the INotifyPropertyChanged interface to Material class, so that MaterialList collection reflects the changes in material.Keywords property.