{"id":2414,"date":"2012-08-15T07:25:53","date_gmt":"2012-08-15T07:25:53","guid":{"rendered":"https:\/\/blogs.msdn.microsoft.com\/webdev\/2012\/08\/15\/using-dynamic-data-with-entity-framework-dbcontext\/"},"modified":"2012-08-15T07:25:53","modified_gmt":"2012-08-15T07:25:53","slug":"using-dynamic-data-with-entity-framework-dbcontext","status":"publish","type":"post","link":"https:\/\/devblogs.microsoft.com\/dotnet\/using-dynamic-data-with-entity-framework-dbcontext\/","title":{"rendered":"Using Dynamic Data with Entity Framework DbContext"},"content":{"rendered":"

In Visual Studio 2012, if you create a ADO.NET Data Model then the generated Context class derives from a type called DbContext<\/a> instead of ObjectContext. DbContext is also used when you are using EntityFramework<\/a> Code First<\/p>\n

This post outlines the changes you have to do to your Dynamicdata project template if you want your context to derive from DbContext<\/p>\n

1. Change Global.asax to get the ObjectContext<\/h3>\n
\n
\n
 DefaultModel.RegisterContext(() =><\/pre>\n
            {<\/pre>\n
                return<\/span> ((IObjectContextAdapter)new<\/span> YourContextType()).ObjectContext;<\/pre>\n
            }, new<\/span> ContextConfiguration() { ScaffoldAllTables = true<\/span> });<\/pre>\n<\/p><\/div>\n<\/p><\/div>\n
2. Change ManyToMany.ascx.cs in the Dynamicdata\\Fieldtemplates folder<\/h3>\n
\n
protected<\/span> override<\/span> void<\/span> OnDataBinding(EventArgs e)<\/pre>\n
        {<\/pre>\n
            base<\/span>.OnDataBinding(e);<\/pre>\n
 <\/pre>\n
            object<\/span> entity;<\/pre>\n
            ICustomTypeDescriptor rowDescriptor = Row as<\/span> ICustomTypeDescriptor;<\/pre>\n
            if<\/span> (rowDescriptor != null<\/span>)<\/pre>\n
            {<\/pre>\n
                \/\/ Get the real entity from the wrapper<\/span><\/pre>\n
                entity = rowDescriptor.GetPropertyOwner(null<\/span>);<\/pre>\n
            }<\/pre>\n
            else<\/span><\/pre>\n
            {<\/pre>\n
                entity = Row;<\/pre>\n
            }<\/pre>\n
 <\/pre>\n
            \/\/ Get the collection and make sure it's loaded<\/span><\/pre>\n
            var entityCollection = Column.EntityTypeProperty.GetValue(entity, null<\/span>);<\/pre>\n
            var realEntityCollection = entityCollection as<\/span> RelatedEnd;<\/pre>\n
            if<\/span> (realEntityCollection != null<\/span> && !realEntityCollection.IsLoaded)<\/pre>\n
            {<\/pre>\n
                realEntityCollection.Load();<\/pre>\n
            }<\/pre>\n
 <\/pre>\n
 <\/pre>\n
            \/\/ Bind the repeater to the list of children entities<\/span><\/pre>\n
            Repeater1.DataSource = entityCollection;<\/pre>\n
            Repeater1.DataBind();<\/pre>\n
        }<\/pre>\n
 <\/pre>\n
        public<\/span> override<\/span> Control DataControl<\/pre>\n
        {<\/pre>\n
            get<\/pre>\n
            {<\/pre>\n
                return<\/span> Repeater1;<\/pre>\n
            }<\/pre>\n
        }<\/pre>\n<\/div>\n
<\/font><\/strong><\/p>\n
3. Change ManyToMany_Edit.ascx.cs in the Dynamicdata\\Fieldtemplates folder<\/h3>\n
\n
protected<\/span> ObjectContext ObjectContext { get; set; }<\/pre>\n
 <\/pre>\n
        public<\/span> void<\/span> Page_Load(object<\/span> sender, EventArgs e)<\/pre>\n
        {<\/pre>\n
            \/\/ Register for the DataSource's updating event<\/span><\/pre>\n
            EntityDataSource ds = (EntityDataSource)this<\/span>.FindDataSourceControl();<\/pre>\n
 <\/pre>\n
            ds.ContextCreated += (_, ctxCreatedEnventArgs) => ObjectContext = ctxCreatedEnventArgs.Context;<\/pre>\n
 <\/pre>\n
            \/\/ This field template is used both for Editing and Inserting<\/span><\/pre>\n
            ds.Updating += new<\/span> EventHandler<EntityDataSourceChangingEventArgs>(DataSource_UpdatingOrInserting);<\/pre>\n
            ds.Inserting += new<\/span> EventHandler<EntityDataSourceChangingEventArgs>(DataSource_UpdatingOrInserting);<\/pre>\n
        }<\/pre>\n
 <\/pre>\n
        void<\/span> DataSource_UpdatingOrInserting(object<\/span> sender, EntityDataSourceChangingEventArgs e)<\/pre>\n
        {<\/pre>\n
            MetaTable childTable = ChildrenColumn.ChildTable;<\/pre>\n
 <\/pre>\n
            \/\/ Comments assume employee\/territory for illustration, but the code is generic<\/span><\/pre>\n
            if<\/span> (Mode == DataBoundControlMode.Edit)<\/pre>\n
            {<\/pre>\n
                ObjectContext.LoadProperty(e.Entity, Column.Name);<\/pre>\n
            }<\/pre>\n
 <\/pre>\n
            \/\/ Get the collection and make sure it's loaded<\/span><\/pre>\n
            dynamic entityCollection = Column.EntityTypeProperty.GetValue(e.Entity, null<\/span>);<\/pre>\n
 <\/pre>\n
            \/\/ Go through all the territories (not just those for this employee)<\/span><\/pre>\n
            foreach<\/span> (dynamic childEntity in<\/span> childTable.GetQuery(e.Context))<\/pre>\n
            {<\/pre>\n
 <\/pre>\n
                \/\/ Check if the employee currently has this territory<\/span><\/pre>\n
                var isCurrentlyInList = ListContainsEntity(childTable, entityCollection, childEntity);<\/pre>\n
 <\/pre>\n
                \/\/ Find the checkbox for this territory, which gives us the new state<\/span><\/pre>\n
                string<\/span> pkString = childTable.GetPrimaryKeyString(childEntity);<\/pre>\n
                ListItem listItem = CheckBoxList1.Items.FindByValue(pkString);<\/pre>\n
                if<\/span> (listItem == null<\/span>)<\/pre>\n
                    continue<\/span>;<\/pre>\n
 <\/pre>\n
                \/\/ If the states differs, make the appropriate add\/remove change<\/span><\/pre>\n
                if<\/span> (listItem.Selected)<\/pre>\n
                {<\/pre>\n
                    if<\/span> (!isCurrentlyInList)<\/pre>\n
                        entityCollection.Add(childEntity);<\/pre>\n
                }<\/pre>\n
                else<\/span><\/pre>\n
                {<\/pre>\n
                    if<\/span> (isCurrentlyInList)<\/pre>\n
                        entityCollection.Remove(childEntity);<\/pre>\n
                }<\/pre>\n
            }<\/pre>\n
        }<\/pre>\n
 <\/pre>\n
        private<\/span> static<\/span> bool<\/span> ListContainsEntity(MetaTable table, IEnumerable<object<\/span>> list, object<\/span> entity)<\/pre>\n
        {<\/pre>\n
            return<\/span> list.Any(e => AreEntitiesEqual(table, e, entity));<\/pre>\n
        }<\/pre>\n
 <\/pre>\n
        private<\/span> static<\/span> bool<\/span> AreEntitiesEqual(MetaTable table, object<\/span> entity1, object<\/span> entity2)<\/pre>\n
        {<\/pre>\n
            return<\/span> Enumerable.SequenceEqual(table.GetPrimaryKeyValues(entity1), table.GetPrimaryKeyValues(entity2));<\/pre>\n
        }<\/pre>\n
 <\/pre>\n
        protected<\/span> void<\/span> CheckBoxList1_DataBound(object<\/span> sender, EventArgs e)<\/pre>\n
        {<\/pre>\n
            MetaTable childTable = ChildrenColumn.ChildTable;<\/pre>\n
 <\/pre>\n
            \/\/ Comments assume employee\/territory for illustration, but the code is generic<\/span><\/pre>\n
 <\/pre>\n
            IEnumerable<object<\/span>> entityCollection = null<\/span>;<\/pre>\n
 <\/pre>\n
            if<\/span> (Mode == DataBoundControlMode.Edit)<\/pre>\n
            {<\/pre>\n
                object<\/span> entity;<\/pre>\n
                ICustomTypeDescriptor rowDescriptor = Row as<\/span> ICustomTypeDescriptor;<\/pre>\n
                if<\/span> (rowDescriptor != null<\/span>)<\/pre>\n
                {<\/pre>\n
                    \/\/ Get the real entity from the wrapper<\/span><\/pre>\n
                    entity = rowDescriptor.GetPropertyOwner(null<\/span>);<\/pre>\n
                }<\/pre>\n
                else<\/span><\/pre>\n
                {<\/pre>\n
                    entity = Row;<\/pre>\n
                }<\/pre>\n
 <\/pre>\n
                \/\/ Get the collection of territories for this employee and make sure it's loaded<\/span><\/pre>\n
                entityCollection = (IEnumerable<object<\/span>>)Column.EntityTypeProperty.GetValue(entity, null<\/span>);<\/pre>\n
                var realEntityCollection = entityCollection as<\/span> RelatedEnd;<\/pre>\n
                if<\/span> (realEntityCollection != null<\/span> && !realEntityCollection.IsLoaded)<\/pre>\n
                {<\/pre>\n
                    realEntityCollection.Load();<\/pre>\n
                }<\/pre>\n
            }<\/pre>\n
 <\/pre>\n
            \/\/ Go through all the territories (not just those for this employee)<\/span><\/pre>\n
            foreach<\/span> (object<\/span> childEntity in<\/span> childTable.GetQuery(ObjectContext))<\/pre>\n
            {<\/pre>\n
                \/\/ Create a checkbox for it<\/span><\/pre>\n
                ListItem listItem = new<\/span> ListItem(<\/pre>\n
                    childTable.GetDisplayString(childEntity),<\/pre>\n
                    childTable.GetPrimaryKeyString(childEntity));<\/pre>\n
 <\/pre>\n
                \/\/ Make it selected if the current employee has that territory<\/span><\/pre>\n
                if<\/span> (Mode == DataBoundControlMode.Edit)<\/pre>\n
                {<\/pre>\n
                    listItem.Selected = ListContainsEntity(childTable, entityCollection, childEntity);<\/pre>\n
                }<\/pre>\n
 <\/pre>\n
                CheckBoxList1.Items.Add(listItem);<\/pre>\n
            }<\/pre>\n
        }<\/pre>\n
 <\/pre>\n
        public<\/span> override<\/span> Control DataControl<\/pre>\n
        {<\/pre>\n
            get<\/pre>\n
            {<\/pre>\n
                return<\/span> CheckBoxList1;<\/pre>\n
            }<\/pre>\n
        }<\/pre>\n<\/div>\n
 <\/pre>\n
At this point you should be good to run your application and use DbContext or EntityFramework Code First with Dynamicdata templates<\/p>\n","protected":false},"excerpt":{"rendered":"
In Visual Studio 2012, if you create a ADO.NET Data Model then the generated Context class derives from a type called DbContext instead of ObjectContext. DbContext is also used when you are using EntityFramework Code First This post outlines the changes you have to do to your Dynamicdata project template if you want your context […]<\/p>\n","protected":false},"author":408,"featured_media":58792,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[197],"tags":[],"class_list":["post-2414","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-aspnet"],"acf":[],"blog_post_summary":"
In Visual Studio 2012, if you create a ADO.NET Data Model then the generated Context class derives from a type called DbContext instead of ObjectContext. DbContext is also used when you are using EntityFramework Code First This post outlines the changes you have to do to your Dynamicdata project template if you want your context […]<\/p>\n","_links":{"self":[{"href":"https:\/\/devblogs.microsoft.com\/dotnet\/wp-json\/wp\/v2\/posts\/2414","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/devblogs.microsoft.com\/dotnet\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/devblogs.microsoft.com\/dotnet\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/devblogs.microsoft.com\/dotnet\/wp-json\/wp\/v2\/users\/408"}],"replies":[{"embeddable":true,"href":"https:\/\/devblogs.microsoft.com\/dotnet\/wp-json\/wp\/v2\/comments?post=2414"}],"version-history":[{"count":0,"href":"https:\/\/devblogs.microsoft.com\/dotnet\/wp-json\/wp\/v2\/posts\/2414\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/devblogs.microsoft.com\/dotnet\/wp-json\/wp\/v2\/media\/58792"}],"wp:attachment":[{"href":"https:\/\/devblogs.microsoft.com\/dotnet\/wp-json\/wp\/v2\/media?parent=2414"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/devblogs.microsoft.com\/dotnet\/wp-json\/wp\/v2\/categories?post=2414"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/devblogs.microsoft.com\/dotnet\/wp-json\/wp\/v2\/tags?post=2414"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}