如何使用EF 4.x DbContext生成器获取属性更改通知
我正在玩Entity Framework 4.3，所以我使用DbContext生成器来创build上下文和实体类。
使用默认的EF 4代码生成器模板，实体类实现INotifyPropertyChanged，并在属性设置器中添加Changing和Changed部分方法。
当我使用EF 4.x DbContext生成器时，如下图所示，实体类要轻得多，并且不包含任何跟踪属性更改的方法。
这里是一个例子：
//------------------------------------------------------------------------------ // <auto-generated> // This code was generated from a template. // // Manual changes to this file may cause unexpected behavior in your application. // Manual changes to this file will be overwritten if the code is regenerated. // </auto-generated> //------------------------------------------------------------------------------ using System; using System.Collections.Generic; namespace SomeNamespace { public partial class SomeTable { public SomeTable() { this.Children = new HashSet<Child>(); } public long parent_id { get; set; } public long id { get; set; } public string filename { get; set; } public byte[] file_blob { get; set; } public virtual Parent Parent { get; set; } public virtual ICollection<Child> Children { get; set; } } }
我必须错过一个重要的难题，但是我的search没有结果。 所以我的问题是：如何使用EF 4.3生成包含属性更改通知的types？
编辑
我完全同意@derape的答案; 但我很好奇，为什么当EF 4默认代码生成模板已经具有钩子时，我需要更改.tt文件。 我的意思是什么时绑定到一个WPF的DependencyProperty '？ 如果没有INotifyPropertyChanged，通过命令对一堆对象中的一堆属性所做的更改将不会反映在UI中。 我错过了什么？
我最近偶然发现了这个问题，我编辑了我的Entity.tt来实现下面的变化，一个快速的补丁，但是很好用。
将以下内容添加到CodeStringGenerator类中
public string EntityClassOpening(EntityType entity) { return string.Format( CultureInfo.InvariantCulture, "{0} {1}partial class {2}{3} : {4}", Accessibility.ForType(entity), _code.SpaceAfter(_code.AbstractOption(entity)), _code.Escape(entity), _code.StringBefore(" : ", _typeMapper.GetTypeName(entity.BaseType)), "INotifyPropertyChanged"); } public string Property(EdmProperty edmProperty) { return string.Format( CultureInfo.InvariantCulture, "{0} {1} {2} {{ {3}{6} {4}{5} }}", Accessibility.ForProperty(edmProperty), _typeMapper.GetTypeName(edmProperty.TypeUsage), _code.Escape(edmProperty), _code.SpaceAfter(Accessibility.ForGetter(edmProperty)), _code.SpaceAfter(Accessibility.ForSetter(edmProperty)), "set { _"+_code.Escape(edmProperty).ToLower()+" = value; OnPropertyChanged(\""+_code.Escape(edmProperty)+"\");}", "get { return _"+_code.Escape(edmProperty).ToLower()+"; }"); } public string Private(EdmProperty edmProperty) { return string.Format( CultureInfo.InvariantCulture, "{0} {1} _{2};", "private", _typeMapper.GetTypeName(edmProperty.TypeUsage), _code.Escape(edmProperty).ToLower()); }
将以下内容添加到生成器
using System.ComponentModel; <#=codeStringGenerator.EntityClassOpening(entity)#> { <# var propertiesWithDefaultValues = typeMapper.GetPropertiesWithDefaultValues(entity); var collectionNavigationProperties = typeMapper.GetCollectionNavigationProperties(entity); var complexProperties = typeMapper.GetComplexProperties(entity); #> public event PropertyChangedEventHandler PropertyChanged; protected virtual void OnPropertyChanged(string propertyName) { PropertyChangedEventHandler handler = PropertyChanged; if (handler != null) handler(this, new PropertyChangedEventArgs(propertyName)); }
并进一步降低
foreach (var edmProperty in simpleProperties) { #> <#=codeStringGenerator.Private(edmProperty)#> <#=codeStringGenerator.Property(edmProperty)#> <# } foreach(var complexProperty in complexProperties) { #> <#=codeStringGenerator.Private(complexProperty)#> <#=codeStringGenerator.Property(complexProperty)#> <# }
我在Anders的回答中创build了一个变体，但有以下区别：
- 对Entity.tt文件的更改较less
- 使用INotifyPropertyChanged实现的基类（便于引入其他常用function）
- 在生成的模型类中清除代码布局
所以我的步骤是：
为您的模型类创build一个基类来扩展：
public abstract class BaseModel : INotifyPropertyChanged { protected bool SetProperty<T>(ref T storage, T value, [CallerMemberName] String propertyName = null) { if (object.Equals(storage, value)) return false; storage = value; this.OnPropertyChanged(propertyName); return true; } public event PropertyChangedEventHandler PropertyChanged; protected virtual void OnPropertyChanged(string propertyName) { PropertyChangedEventHandler handler = PropertyChanged; if (handler != null) handler(this, new PropertyChangedEventArgs(propertyName)); } }
感谢胡安·波戈·戈麦斯的build议改进！ 即使其他评论者没有，我也喜欢你的改进:)
将Entity.tt文件中的EntityClassOpening方法更新为以下内容：
public string EntityClassOpening(EntityType entity) { return string.Format( CultureInfo.InvariantCulture, "{0} {1}partial class {2}{3}", Accessibility.ForType(entity), _code.SpaceAfter(_code.AbstractOption(entity)), _code.Escape(entity), _code.StringBefore(" : ", string.IsNullOrEmpty(_typeMapper.GetTypeName(entity.BaseType)) ? "BaseModel" : _typeMapper.GetTypeName(entity.BaseType))); }
find这一行：
<#=Accessibility.ForType(complex)#> partial class <#=code.Escape(complex)#>
并更新它是：
<#=Accessibility.ForType(complex)#> partial class <#=code.Escape(complex)#> : BaseModel
感谢Manolo！
将Entity.tt文件中的Property方法更新为以下内容：
public string Property(EdmProperty edmProperty) { return string.Format( CultureInfo.InvariantCulture, "private {1} {3};\r\n"+ "\t{0} {1} {2} \r\n" + "\t{{ \r\n" + "\t\t{4}get {{ return {3}; }} \r\n" + "\t\t{5}set {{ SetProperty(ref {3}, value); }} \r\n" + "\t}}\r\n", Accessibility.ForProperty(edmProperty), _typeMapper.GetTypeName(edmProperty.TypeUsage), _code.Escape(edmProperty), "_" + Char.ToLowerInvariant(_code.Escape(edmProperty)[0]) + _code.Escape(edmProperty).Substring(1), _code.SpaceAfter(Accessibility.ForGetter(edmProperty)), _code.SpaceAfter(Accessibility.ForSetter(edmProperty))); }
你完成了！ 现在你的模型类将如下所示：
public partial class User : BaseModel { private int _id; public int Id { get { return _id; } set { SetProperty(ref _id,value);} } private string _name; public string Name { get { return _name; } set { SetProperty(ref _name , value); } }
请随时（尝试）编辑此解决scheme，如果你能看到其他的改进。
我试图编辑Brian Hinchey解决scheme，但编辑被拒绝。 然后我在这里张贴我的addapts。
此解决scheme利用CallerMemberName属性为每个属性Setter生成更less的代码。
注：我使用EF 6.1，它工作得很好。
BaseClass现在看起来像这样。
public abstract class BaseModel : INotifyPropertyChanged { public event PropertyChangedEventHandler PropertyChanged; protected bool SetProperty<T>(ref T storage, T value, [CallerMemberName] String propertyName = null) { if (object.Equals(storage, value)) return false; storage = value; this.OnPropertyChanged(propertyName); return true; } protected void OnPropertyChanged([CallerMemberName] string propertyName = null) { var eventHandler = this.PropertyChanged; if (eventHandler != null) { eventHandler(this, new PropertyChangedEventArgs(propertyName)); } } }
更新Entity.tt中的EntityClassOpening方法与Brian完全一样：
public string EntityClassOpening(EntityType entity) { return string.Format( CultureInfo.InvariantCulture, "{0} {1}partial class {2}{3}", Accessibility.ForType(entity), _code.SpaceAfter(_code.AbstractOption(entity)), _code.Escape(entity), _code.StringBefore(" : ", string.IsNullOrEmpty(_typeMapper.GetTypeName(entity.BaseType)) ? "BaseModel" : _typeMapper.GetTypeName(entity.BaseType))); }
正如布莱恩说的那样记住变化：
<#=Accessibility.ForType(complex)#> partial class <#=code.Escape(complex)#> FOR <#=Accessibility.ForType(complex)#> partial class <#=code.Escape(complex)#> : BaseModel
而我最后的改变是对于Property方法
public string Property(EdmProperty edmProperty) { return string.Format( CultureInfo.InvariantCulture, "private {1} {3};\r\n"+ "\t{0} {1} {2} \r\n" + "\t{{ \r\n" + "\t\t{4}get {{ return {3}; }} \r\n" + "\t\t{5}set {{ SetProperty(ref {3}, value); }} \r\n" + "\t}}\r\n", Accessibility.ForProperty(edmProperty), _typeMapper.GetTypeName(edmProperty.TypeUsage), _code.Escape(edmProperty), "_" + Char.ToLowerInvariant(_code.Escape(edmProperty)[0]) + _code.Escape(edmProperty).Substring(1), _code.SpaceAfter(Accessibility.ForGetter(edmProperty)), _code.SpaceAfter(Accessibility.ForSetter(edmProperty))); }
最后这里是这个类的样子：
public partial class User : BaseModel { private int _id; public int Id { get { return _id; } set { SetProperty(ref _id , value);} } private string _name; public string Name { get { return _name; } set { SetProperty(ref _name , value);} } }
这使得生成的分类更轻。
最近我正在使用PropertyChanged.Fody库，但由于不知道的原因（至less对我而言）它有时不能正常工作。 这就是我在这里的原因。 这个解决scheme（布赖恩的解决scheme）每次都有效。
上面Anders的解决scheme可行，但是在这个过程中我发现了一些问题：
在步骤1中，“将以下内容添加到CodeStringGenerator类”中，只能添加“public string Private（…”）函数，因为其他两个函数已经存在了，所以需要find它们并replace这两个函数不要添加它们，否则你会得到错误。要准确find需要放置的位置，请search“公共类CodeStringGenerator”，然后查找下面的函数。
在步骤2“将以下内容添加到生成器”中，您只需添加“使用System.ComponentModel”行，以及（和包含）“public event PropertyChangedEventHandler …”中的行。 再次，其他行已经存在，你会发现他们靠近.tt文件的顶部。
在第3步“再往下”，这两个“foreach”循环也已经存在，所以它们必须被replace而不被添加。 最终只有一行被添加到每个foreach循环中，分别在每个循环中添加“<＃= codeStringGenerator.Private（edmProperty）＃>”和“<＃= codeStringGenerator.Private（complexProperty）＃>”。
此外，不要更换错误的循环，有两个额外的循环上面你需要更换哪些都循环通过相同的对象…确保您replace正确的:-)
我想我会提到这一点，因为作为一个MVVM / EF新手（用于使用NHibernate），我不得不作出这些调整工作。
那么这取决于你正在尝试做什么。 如果你只是想实现自定义的属性/方法，你可以使用部分类的funcionality。 如果你想改变你的实体devise器的setter / getter属性，你必须修改dbContext生成器模板文件。 这是一个T4模板。
我创build了以下用于EF 6.1.2，但testing已经相当有限，所以使用风险自担。
<#@ template language="C#" debug="false" hostspecific="true"#> <#@ include file="EF6.Utility.CS.ttinclude"#><#@ output extension=".cs"#><# const string inputFile = @"Model.edmx"; var textTransform = DynamicTextTransformation.Create(this); var code = new CodeGenerationTools(this); var ef = new MetadataTools(this); var typeMapper = new TypeMapper(code, ef, textTransform.Errors); var fileManager = EntityFrameworkTemplateFileManager.Create(this); var itemCollection = new EdmMetadataLoader(textTransform.Host, textTransform.Errors).CreateEdmItemCollection(inputFile); var codeStringGenerator = new CodeStringGenerator(code, typeMapper, ef); if (!typeMapper.VerifyCaseInsensitiveTypeUniqueness(typeMapper.GetAllGlobalItems(itemCollection), inputFile)) { return string.Empty; } WriteHeader(codeStringGenerator, fileManager); foreach (var entity in typeMapper.GetItemsToGenerate<EntityType>(itemCollection)) { fileManager.StartNewFile(entity.Name + ".cs"); BeginNamespace(code); #> <#=codeStringGenerator.UsingDirectives(inHeader: false)#> <#=codeStringGenerator.EntityClassOpening(entity)#> { <# var propertiesWithDefaultValues = typeMapper.GetPropertiesWithDefaultValues(entity); var collectionNavigationProperties = typeMapper.GetCollectionNavigationProperties(entity); var complexProperties = typeMapper.GetComplexProperties(entity); if (propertiesWithDefaultValues.Any() || collectionNavigationProperties.Any() || complexProperties.Any()) { #> [System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Usage", "CA2214:DoNotCallOverridableMethodsInConstructors")] public <#=code.Escape(entity)#>() { <# foreach (var edmProperty in propertiesWithDefaultValues) { #> this.<#=code.Escape(edmProperty)#> = <#=typeMapper.CreateLiteral(edmProperty.DefaultValue)#>; <# } foreach (var navigationProperty in collectionNavigationProperties) { #> this.<#=code.Escape(navigationProperty)#> = new HashSet<<#=typeMapper.GetTypeName(navigationProperty.ToEndMember.GetEntityType())#>>(); <# } foreach (var complexProperty in complexProperties) { #> this.<#=code.Escape(complexProperty)#> = new <#=typeMapper.GetTypeName(complexProperty.TypeUsage)#>(); <# } #> } <# } var simpleProperties = typeMapper.GetSimpleProperties(entity); if (simpleProperties.Any()) { foreach (var edmProperty in simpleProperties) { #> <#=codeStringGenerator.Property(edmProperty)#> <# } } if (complexProperties.Any()) { #> <# foreach(var complexProperty in complexProperties) { #> <#=codeStringGenerator.Property(complexProperty)#> <# } } var navigationProperties = typeMapper.GetNavigationProperties(entity); if (navigationProperties.Any()) { #> <# foreach (var navigationProperty in navigationProperties) { if (navigationProperty.ToEndMember.RelationshipMultiplicity == RelationshipMultiplicity.Many) { #> [System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Usage", "CA2227:CollectionPropertiesShouldBeReadOnly")] <# } #> <#=codeStringGenerator.NavigationProperty(navigationProperty)#> <# } } #> #region INotifyPropertyChanged Members public event PropertyChangedEventHandler PropertyChanged; protected void OnPropertyChanged(string propertyName) { OnPropertyChanged(new PropertyChangedEventArgs(propertyName)); } protected virtual void OnPropertyChanged(PropertyChangedEventArgs e) { WhenPropertyChanged(e); if (PropertyChanged != null) { PropertyChanged(this, e); } } partial void WhenPropertyChanged(PropertyChangedEventArgs e); #endregion } <# EndNamespace(code); } foreach (var complex in typeMapper.GetItemsToGenerate<ComplexType>(itemCollection)) { fileManager.StartNewFile(complex.Name + ".cs"); BeginNamespace(code); #> <#=codeStringGenerator.UsingDirectives(inHeader: false, includeCollections: false)#> <#=Accessibility.ForType(complex)#> partial class <#=code.Escape(complex)#> { <# var complexProperties = typeMapper.GetComplexProperties(complex); var propertiesWithDefaultValues = typeMapper.GetPropertiesWithDefaultValues(complex); if (propertiesWithDefaultValues.Any() || complexProperties.Any()) { #> public <#=code.Escape(complex)#>() { <# foreach (var edmProperty in propertiesWithDefaultValues) { #> this.<#=code.Escape(edmProperty)#> = <#=typeMapper.CreateLiteral(edmProperty.DefaultValue)#>; <# } foreach (var complexProperty in complexProperties) { #> this.<#=code.Escape(complexProperty)#> = new <#=typeMapper.GetTypeName(complexProperty.TypeUsage)#>(); <# } #> } <# } var simpleProperties = typeMapper.GetSimpleProperties(complex); if (simpleProperties.Any()) { foreach(var edmProperty in simpleProperties) { #> <#=codeStringGenerator.Property(edmProperty)#> <# } } if (complexProperties.Any()) { #> <# foreach(var edmProperty in complexProperties) { #> <#=codeStringGenerator.Property(edmProperty)#> <# } } #> } <# EndNamespace(code); } foreach (var enumType in typeMapper.GetEnumItemsToGenerate(itemCollection)) { fileManager.StartNewFile(enumType.Name + ".cs"); BeginNamespace(code); #> <#=codeStringGenerator.UsingDirectives(inHeader: false, includeCollections: false)#> <# if (typeMapper.EnumIsFlags(enumType)) { #> [Flags] <# } #> <#=codeStringGenerator.EnumOpening(enumType)#> { <# var foundOne = false; foreach (MetadataItem member in typeMapper.GetEnumMembers(enumType)) { foundOne = true; #> <#=code.Escape(typeMapper.GetEnumMemberName(member))#> = <#=typeMapper.GetEnumMemberValue(member)#>, <# } if (foundOne) { this.GenerationEnvironment.Remove(this.GenerationEnvironment.Length - 3, 1); } #> } <# EndNamespace(code); } fileManager.Process(); #> <#+ public void WriteHeader(CodeStringGenerator codeStringGenerator, EntityFrameworkTemplateFileManager fileManager) { fileManager.StartHeader(); #> //------------------------------------------------------------------------------ // <auto-generated> // <#=CodeGenerationTools.GetResourceString("Template_GeneratedCodeCommentLine1")#> // // <#=CodeGenerationTools.GetResourceString("Template_GeneratedCodeCommentLine2")#> // <#=CodeGenerationTools.GetResourceString("Template_GeneratedCodeCommentLine3")#> // </auto-generated> //------------------------------------------------------------------------------ <#=codeStringGenerator.UsingDirectives(inHeader: true)#> <#+ fileManager.EndBlock(); } public void BeginNamespace(CodeGenerationTools code) { var codeNamespace = code.VsNamespaceSuggestion(); if (!String.IsNullOrEmpty(codeNamespace)) { #> namespace <#=code.EscapeNamespace(codeNamespace)#> { <#+ PushIndent(" "); } } public void EndNamespace(CodeGenerationTools code) { if (!String.IsNullOrEmpty(code.VsNamespaceSuggestion())) { PopIndent(); #> } <#+ } } public const string TemplateId = "CSharp_DbContext_Types_EF6"; public class CodeStringGenerator { private readonly CodeGenerationTools _code; private readonly TypeMapper _typeMapper; private readonly MetadataTools _ef; public CodeStringGenerator(CodeGenerationTools code, TypeMapper typeMapper, MetadataTools ef) { ArgumentNotNull(code, "code"); ArgumentNotNull(typeMapper, "typeMapper"); ArgumentNotNull(ef, "ef"); _code = code; _typeMapper = typeMapper; _ef = ef; } public string Property(EdmProperty edmProperty) { StringBuilder propertyCode = new StringBuilder(); propertyCode.AppendFormat("private {0} _{1};",_typeMapper.GetTypeName(edmProperty.TypeUsage), _code.Escape(edmProperty)); propertyCode.AppendFormat( CultureInfo.InvariantCulture, "{0} {1} {2} {{ {3}get{{ return _{2};}} {4}set{{if(_{2} != value){{_{2} = value; OnPropertyChanged(\"{2}\");}}}}}}", Accessibility.ForProperty(edmProperty), _typeMapper.GetTypeName(edmProperty.TypeUsage), _code.Escape(edmProperty), _code.SpaceAfter(Accessibility.ForGetter(edmProperty)), _code.SpaceAfter(Accessibility.ForSetter(edmProperty))); return propertyCode.ToString(); } public string NavigationProperty(NavigationProperty navProp) { var endType = _typeMapper.GetTypeName(navProp.ToEndMember.GetEntityType()); return string.Format( CultureInfo.InvariantCulture, "{0} {1} {2} {{ {3}get; {4}set; }}", AccessibilityAndVirtual(Accessibility.ForNavigationProperty(navProp)), navProp.ToEndMember.RelationshipMultiplicity == RelationshipMultiplicity.Many ? ("ICollection<" + endType + ">") : endType, _code.Escape(navProp), _code.SpaceAfter(Accessibility.ForGetter(navProp)), _code.SpaceAfter(Accessibility.ForSetter(navProp))); } public string AccessibilityAndVirtual(string accessibility) { return accessibility + (accessibility != "private" ? " virtual" : ""); } public string EntityClassOpening(EntityType entity) { return string.Format( CultureInfo.InvariantCulture, "{0} {1}partial class {2} : INotifyPropertyChanged{3}", Accessibility.ForType(entity), _code.SpaceAfter(_code.AbstractOption(entity)), _code.Escape(entity), _code.StringBefore(", ", _typeMapper.GetTypeName(entity.BaseType))); } public string EnumOpening(SimpleType enumType) { return string.Format( CultureInfo.InvariantCulture, "{0} enum {1} : {2}", Accessibility.ForType(enumType), _code.Escape(enumType), _code.Escape(_typeMapper.UnderlyingClrType(enumType))); } public void WriteFunctionParameters(EdmFunction edmFunction, Action<string, string, string, string> writeParameter) { var parameters = FunctionImportParameter.Create(edmFunction.Parameters, _code, _ef); foreach (var parameter in parameters.Where(p => p.NeedsLocalVariable)) { var isNotNull = parameter.IsNullableOfT ? parameter.FunctionParameterName + ".HasValue" : parameter.FunctionParameterName + " != null"; var notNullInit = "new ObjectParameter(\"" + parameter.EsqlParameterName + "\", " + parameter.FunctionParameterName + ")"; var nullInit = "new ObjectParameter(\"" + parameter.EsqlParameterName + "\", typeof(" + TypeMapper.FixNamespaces(parameter.RawClrTypeName) + "))"; writeParameter(parameter.LocalVariableName, isNotNull, notNullInit, nullInit); } } public string ComposableFunctionMethod(EdmFunction edmFunction, string modelNamespace) { var parameters = _typeMapper.GetParameters(edmFunction); return string.Format( CultureInfo.InvariantCulture, "{0} IQueryable<{1}> {2}({3})", AccessibilityAndVirtual(Accessibility.ForMethod(edmFunction)), _typeMapper.GetTypeName(_typeMapper.GetReturnType(edmFunction), modelNamespace), _code.Escape(edmFunction), string.Join(", ", parameters.Select(p => TypeMapper.FixNamespaces(p.FunctionParameterType) + " " + p.FunctionParameterName).ToArray())); } public string ComposableCreateQuery(EdmFunction edmFunction, string modelNamespace) { var parameters = _typeMapper.GetParameters(edmFunction); return string.Format( CultureInfo.InvariantCulture, "return ((IObjectContextAdapter)this).ObjectContext.CreateQuery<{0}>(\"[{1}].[{2}]({3})\"{4});", _typeMapper.GetTypeName(_typeMapper.GetReturnType(edmFunction), modelNamespace), edmFunction.NamespaceName, edmFunction.Name, string.Join(", ", parameters.Select(p => "@" + p.EsqlParameterName).ToArray()), _code.StringBefore(", ", string.Join(", ", parameters.Select(p => p.ExecuteParameterName).ToArray()))); } public string FunctionMethod(EdmFunction edmFunction, string modelNamespace, bool includeMergeOption) { var parameters = _typeMapper.GetParameters(edmFunction); var returnType = _typeMapper.GetReturnType(edmFunction); var paramList = String.Join(", ", parameters.Select(p => TypeMapper.FixNamespaces(p.FunctionParameterType) + " " + p.FunctionParameterName).ToArray()); if (includeMergeOption) { paramList = _code.StringAfter(paramList, ", ") + "MergeOption mergeOption"; } return string.Format( CultureInfo.InvariantCulture, "{0} {1} {2}({3})", AccessibilityAndVirtual(Accessibility.ForMethod(edmFunction)), returnType == null ? "int" : "ObjectResult<" + _typeMapper.GetTypeName(returnType, modelNamespace) + ">", _code.Escape(edmFunction), paramList); } public string ExecuteFunction(EdmFunction edmFunction, string modelNamespace, bool includeMergeOption) { var parameters = _typeMapper.GetParameters(edmFunction); var returnType = _typeMapper.GetReturnType(edmFunction); var callParams = _code.StringBefore(", ", String.Join(", ", parameters.Select(p => p.ExecuteParameterName).ToArray())); if (includeMergeOption) { callParams = ", mergeOption" + callParams; } return string.Format( CultureInfo.InvariantCulture, "return ((IObjectContextAdapter)this).ObjectContext.ExecuteFunction{0}(\"{1}\"{2});", returnType == null ? "" : "<" + _typeMapper.GetTypeName(returnType, modelNamespace) + ">", edmFunction.Name, callParams); } public string DbSet(EntitySet entitySet) { return string.Format( CultureInfo.InvariantCulture, "{0} virtual DbSet<{1}> {2} {{ get; set; }}", Accessibility.ForReadOnlyProperty(entitySet), _typeMapper.GetTypeName(entitySet.ElementType), _code.Escape(entitySet)); } public string UsingDirectives(bool inHeader, bool includeCollections = true) { return inHeader == string.IsNullOrEmpty(_code.VsNamespaceSuggestion()) ? string.Format( CultureInfo.InvariantCulture, "{0}using System;" + Environment.NewLine + "using System.ComponentModel;{1}" + "{2}", inHeader ? Environment.NewLine : "", includeCollections ? (Environment.NewLine + "using System.Collections.Generic;") : "", inHeader ? "" : Environment.NewLine) : ""; } } public class TypeMapper { private const string ExternalTypeNameAttributeName = @"http://schemas.microsoft.com/ado/2006/04/codegeneration:ExternalTypeName"; private readonly System.Collections.IList _errors; private readonly CodeGenerationTools _code; private readonly MetadataTools _ef; public TypeMapper(CodeGenerationTools code, MetadataTools ef, System.Collections.IList errors) { ArgumentNotNull(code, "code"); ArgumentNotNull(ef, "ef"); ArgumentNotNull(errors, "errors"); _code = code; _ef = ef; _errors = errors; } public static string FixNamespaces(string typeName) { return typeName.Replace("System.Data.Spatial.", "System.Data.Entity.Spatial."); } public string GetTypeName(TypeUsage typeUsage) { return typeUsage == null ? null : GetTypeName(typeUsage.EdmType, _ef.IsNullable(typeUsage), modelNamespace: null); } public string GetTypeName(EdmType edmType) { return GetTypeName(edmType, isNullable: null, modelNamespace: null); } public string GetTypeName(TypeUsage typeUsage, string modelNamespace) { return typeUsage == null ? null : GetTypeName(typeUsage.EdmType, _ef.IsNullable(typeUsage), modelNamespace); } public string GetTypeName(EdmType edmType, string modelNamespace) { return GetTypeName(edmType, isNullable: null, modelNamespace: modelNamespace); } public string GetTypeName(EdmType edmType, bool? isNullable, string modelNamespace) { if (edmType == null) { return null; } var collectionType = edmType as CollectionType; if (collectionType != null) { return String.Format(CultureInfo.InvariantCulture, "ICollection<{0}>", GetTypeName(collectionType.TypeUsage, modelNamespace)); } var typeName = _code.Escape(edmType.MetadataProperties .Where(p => p.Name == ExternalTypeNameAttributeName) .Select(p => (string)p.Value) .FirstOrDefault()) ?? (modelNamespace != null && edmType.NamespaceName != modelNamespace ? _code.CreateFullName(_code.EscapeNamespace(edmType.NamespaceName), _code.Escape(edmType)) : _code.Escape(edmType)); if (edmType is StructuralType) { return typeName; } if (edmType is SimpleType) { var clrType = UnderlyingClrType(edmType); if (!IsEnumType(edmType)) { typeName = _code.Escape(clrType); } typeName = FixNamespaces(typeName); return clrType.IsValueType && isNullable == true ? String.Format(CultureInfo.InvariantCulture, "Nullable<{0}>", typeName) : typeName; } throw new ArgumentException("edmType"); } public Type UnderlyingClrType(EdmType edmType) { ArgumentNotNull(edmType, "edmType"); var primitiveType = edmType as PrimitiveType; if (primitiveType != null) { return primitiveType.ClrEquivalentType; } if (IsEnumType(edmType)) { return GetEnumUnderlyingType(edmType).ClrEquivalentType; } return typeof(object); } public object GetEnumMemberValue(MetadataItem enumMember) { ArgumentNotNull(enumMember, "enumMember"); var valueProperty = enumMember.GetType().GetProperty("Value"); return valueProperty == null ? null : valueProperty.GetValue(enumMember, null); } public string GetEnumMemberName(MetadataItem enumMember) { ArgumentNotNull(enumMember, "enumMember"); var nameProperty = enumMember.GetType().GetProperty("Name"); return nameProperty == null ? null : (string)nameProperty.GetValue(enumMember, null); } public System.Collections.IEnumerable GetEnumMembers(EdmType enumType) { ArgumentNotNull(enumType, "enumType"); var membersProperty = enumType.GetType().GetProperty("Members"); return membersProperty != null ? (System.Collections.IEnumerable)membersProperty.GetValue(enumType, null) : Enumerable.Empty<MetadataItem>(); } public bool EnumIsFlags(EdmType enumType) { ArgumentNotNull(enumType, "enumType"); var isFlagsProperty = enumType.GetType().GetProperty("IsFlags"); return isFlagsProperty != null && (bool)isFlagsProperty.GetValue(enumType, null); } public bool IsEnumType(GlobalItem edmType) { ArgumentNotNull(edmType, "edmType"); return edmType.GetType().Name == "EnumType"; } public PrimitiveType GetEnumUnderlyingType(EdmType enumType) { ArgumentNotNull(enumType, "enumType"); return (PrimitiveType)enumType.GetType().GetProperty("UnderlyingType").GetValue(enumType, null); } public string CreateLiteral(object value) { if (value == null || value.GetType() != typeof(TimeSpan)) { return _code.CreateLiteral(value); } return string.Format(CultureInfo.InvariantCulture, "new TimeSpan({0})", ((TimeSpan)value).Ticks); } public bool VerifyCaseInsensitiveTypeUniqueness(IEnumerable<string> types, string sourceFile) { ArgumentNotNull(types, "types"); ArgumentNotNull(sourceFile, "sourceFile"); var hash = new HashSet<string>(StringComparer.InvariantCultureIgnoreCase); if (types.Any(item => !hash.Add(item))) { _errors.Add( new CompilerError(sourceFile, -1, -1, "6023", String.Format(CultureInfo.CurrentCulture, CodeGenerationTools.GetResourceString("Template_CaseInsensitiveTypeConflict")))); return false; } return true; } public IEnumerable<SimpleType> GetEnumItemsToGenerate(IEnumerable<GlobalItem> itemCollection) { return GetItemsToGenerate<SimpleType>(itemCollection) .Where(e => IsEnumType(e)); } public IEnumerable<T> GetItemsToGenerate<T>(IEnumerable<GlobalItem> itemCollection) where T: EdmType { return itemCollection .OfType<T>() .Where(i => !i.MetadataProperties.Any(p => p.Name == ExternalTypeNameAttributeName)) .OrderBy(i => i.Name); } public IEnumerable<string> GetAllGlobalItems(IEnumerable<GlobalItem> itemCollection) { return itemCollection .Where(i => i is EntityType || i is ComplexType || i is EntityContainer || IsEnumType(i)) .Select(g => GetGlobalItemName(g)); } public string GetGlobalItemName(GlobalItem item) { if (item is EdmType) { return ((EdmType)item).Name; } else { return ((EntityContainer)item).Name; } } public IEnumerable<EdmProperty> GetSimpleProperties(EntityType type) { return type.Properties.Where(p => p.TypeUsage.EdmType is SimpleType && p.DeclaringType == type); } public IEnumerable<EdmProperty> GetSimpleProperties(ComplexType type) { return type.Properties.Where(p => p.TypeUsage.EdmType is SimpleType && p.DeclaringType == type); } public IEnumerable<EdmProperty> GetComplexProperties(EntityType type) { return type.Properties.Where(p => p.TypeUsage.EdmType is ComplexType && p.DeclaringType == type); } public IEnumerable<EdmProperty> GetComplexProperties(ComplexType type) { return type.Properties.Where(p => p.TypeUsage.EdmType is ComplexType && p.DeclaringType == type); } public IEnumerable<EdmProperty> GetPropertiesWithDefaultValues(EntityType type) { return type.Properties.Where(p => p.TypeUsage.EdmType is SimpleType && p.DeclaringType == type && p.DefaultValue != null); } public IEnumerable<EdmProperty> GetPropertiesWithDefaultValues(ComplexType type) { return type.Properties.Where(p => p.TypeUsage.EdmType is SimpleType && p.DeclaringType == type && p.DefaultValue != null); } public IEnumerable<NavigationProperty> GetNavigationProperties(EntityType type) { return type.NavigationProperties.Where(np => np.DeclaringType == type); } public IEnumerable<NavigationProperty> GetCollectionNavigationProperties(EntityType type) { return type.NavigationProperties.Where(np => np.DeclaringType == type && np.ToEndMember.RelationshipMultiplicity == RelationshipMultiplicity.Many); } public FunctionParameter GetReturnParameter(EdmFunction edmFunction) { ArgumentNotNull(edmFunction, "edmFunction"); var returnParamsProperty = edmFunction.GetType().GetProperty("ReturnParameters"); return returnParamsProperty == null ? edmFunction.ReturnParameter : ((IEnumerable<FunctionParameter>)returnParamsProperty.GetValue(edmFunction, null)).FirstOrDefault(); } public bool IsComposable(EdmFunction edmFunction) { ArgumentNotNull(edmFunction, "edmFunction"); var isComposableProperty = edmFunction.GetType().GetProperty("IsComposableAttribute"); return isComposableProperty != null && (bool)isComposableProperty.GetValue(edmFunction, null); } public IEnumerable<FunctionImportParameter> GetParameters(EdmFunction edmFunction) { return FunctionImportParameter.Create(edmFunction.Parameters, _code, _ef); } public TypeUsage GetReturnType(EdmFunction edmFunction) { var returnParam = GetReturnParameter(edmFunction); return returnParam == null ? null : _ef.GetElementType(returnParam.TypeUsage); } public bool GenerateMergeOptionFunction(EdmFunction edmFunction, bool includeMergeOption) { var returnType = GetReturnType(edmFunction); return !includeMergeOption && returnType != null && returnType.EdmType.BuiltInTypeKind == BuiltInTypeKind.EntityType; } } public static void ArgumentNotNull<T>(T arg, string name) where T : class { if (arg == null) { throw new ArgumentNullException(name); } } #>
I work with Visual Basic and tend to enjoy refactoring legacy and non layered architectures.
So, I've worked out how to do this using answers from above but in Entity Framework 6.1.3 and .net 4.6.1.
I've translated from the answers given by others, so I can only take credit for the bit of rediscovery and translation I've done this evening.
The project this is for is quite tiny, it's winforms and I wanted databinding rather than a slew of manual updates to controls. I did NOT want to add even more complexity by adding in more separation as here there was not enough benefit. There's just enough to justify this :).
I hope it helps other VB coders.
The Base class:
Imports System.ComponentModel Imports System.Runtime.CompilerServices Public MustInherit Class BaseModel Implements INotifyPropertyChanged Protected Function SetProperty(Of T)(ByRef storage As T, value As T, <CallerMemberName> Optional propertyName As String = Nothing) As Boolean If Equals(storage, value) Then Return False storage = value OnPropertyChanged(propertyName) Return True End Function Public Event PropertyChanged As PropertyChangedEventHandler Implements INotifyPropertyChanged.PropertyChanged Protected Overridable Sub OnPropertyChanged(propertyName As String) RaiseEvent PropertyChanged(Me, New PropertyChangedEventArgs(propertyName)) End Sub End Class
Public string Property does not exist in the VB TT file (Make sure it's the ModelName.tt not the ModelName.Context.tt). Note the use of the conditional for the nullable comparison. If you don't have this, you won't get the thing firing!
Public Function AnyProperty(accessibility As String, type As String, name As String, getterAccessibility As String, setterAccessibility As String, defaultValue As String) Dim CompareLine = if(type.contains("Null"), $"if Not Nullable.Equals({name}, value) ", $"if {name} <> value ") Return String.Format( _ CultureInfo.InvariantCulture, _ "{6} Private _{0} As {1}{2}{6}" & _ " {3} Property {0} As {1}{6}" & _ " {4}Get{6}" & _ " Return _{0}{6}" & _ " End Get{6}" & _ " {5}Set(ByVal value As {1}){6}" & _ " {7} then SetProperty(_{0}, value){6}" & _ " End Set{6}" & _ " End Property", _ name, _ type, _ defaultValue, _ accessibility, _ getterAccessibility, _ setterAccessibility, _ Environment.NewLine, CompareLine) End Function
EntityClassOpening
Public Function EntityClassOpening(entity As EntityType) As String Return String.Format( _ CultureInfo.InvariantCulture, _ "Partial {0} {1}Class {2}{3}", _ Accessibility.ForType(entity), _ _code.SpaceAfter(_code.MustInheritOption(entity)), _ _code.Escape(entity), _ _code.StringBefore(Environment.Newline & " Inherits ", If(String.IsNullOrEmpty(_typeMapper.GetTypeName(entity.BaseType)), "BaseModel", _typeMapper.GetTypeName(entity.BaseType)))) End Function
If I discover anything significant to add to this, I'll do so.
Please do note my use case: lightweight VB project, no justification for introducing MVVM/MVC and repository layers but plenty of reason to want databinding rather than annoying conditional updates to and from controls – many of which have an EditValue that are of type Object (Devexpress winforms controls).
You should continue using ObjectContext if you want property change notifications when you bind directly to the data model classes.
The lightweight DBContext classes are for patterns such as MVVM or MVVMC where your view model implements property change notifications and your UI only binds to the view model's properties. You never bind to data model classes in these patterns.
