[原创]EF架构随心所欲打造属于你自己的DbModel

2019-11-14 16:08:26

字体：大中小

来源：转载

供稿：网友

前言

我们都知道EF可以生成Dbmodel，系统生成的Model有时候并不是我们想要的，如何我们要生成自己的Model，那么久需要我们手动的去修改T4模版，T4是对“Text Template Transformation Toolkit”（4个T）的简称。如果你对T4不怎么了解可以去看蒋金楠（Artech）文章从数据到代码——基于T4的代码生成方式。

1.0先看看我们要达到的效果图吧

2.0首先我们来修改T4模版吧

打开T4模版，找到代码 WriteHeader(codeStringGenerator, fileManager);

我们首先定义变量（图中黄色代码为我们自己添加的代码）

WriteHeader(codeStringGenerator, fileManager);string summary=string.Empty; 定义变量foreach (var entity in typeMapper.GetItemsToGenerate<EntityType>(itemCollection)){    fileManager.StartNewFile(entity.Name + ".cs");    BeginNamespace(code);       if(entity.Documentation !=null && entity.Documentation.Summary!=null)            summary=entity.Documentation.Summary;        else            summary=entity.Name;#><#=codeStringGenerator.UsingDirectives(inHeader: false)#>using System.ComponentModel.DataAnnotations; 导入你需要的命名空间/// <summary>/// <#=            summary#>给类加注释/// </summary>[Serializable]<#=codeStringGenerator.EntityClassOpening(entity)#>

看看效果图如下：

类上面的注释已经加好了，接下来就是删除构造函数，删除以下代码即可：

    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)#>();<#        }#>    }

接下来我们把这些可空类型还原成本来面目，已经去掉virtual关键字，修改代码如下:

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) :原来的代码
                String.Format(CultureInfo.InvariantCulture, "{0}?", typeName) :自己修改的代码
                typeName;        }        throw new ArgumentException("edmType");    }

   public string NavigationProperty(NavigationProperty navigationProperty)    {        var endType = _typeMapper.GetTypeName(navigationProperty.ToEndMember.GetEntityType());        return string.Format(            CultureInfo.InvariantCulture,            "public {1} {2} {{ {3}get; {4}set; }}",            accessibilityAndVirtual(Accessibility.ForProperty(navigationProperty)),            navigationProperty.ToEndMember.RelationshipMultiplicity == RelationshipMultiplicity.Many ? ("ICollection<" + endType + ">") : endType,            _code.Escape(navigationProperty),            _code.SpaceAfter(Accessibility.ForGetter(navigationProperty)),            _code.SpaceAfter(Accessibility.ForSetter(navigationProperty)));    }

接下来来给属性上添加注释：(橙色代码删除，皇色代码添加)

/// <summary>/// <#=            summary#>/// </summary>[Serializable]<#=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())    {#><#    }删除掉代码    var simpleProperties = typeMapper.GetSimpleProperties(entity);    if (simpleProperties.Any())    {        foreach (var edmProperty in simpleProperties)        {                if (edmProperty.Documentation != null && edmProperty.Documentation.Summary != null)                {                    if(!entity.KeyMembers.Contains(edmProperty.Name))                        summary=edmProperty.Documentation.Summary.ToLower().Replace("id","名称");                    else                        summary=edmProperty.Documentation.Summary;                }                else                {                    summary="";                }#><#                //if(edmProperty.Name.ToLower() == "id")                // continue;var a=edmProperty.Nullable;                                var keyName="";                 if(entity.KeyMembers.Contains(edmProperty.Name))                              keyName="[Key]";                var required="";                if(!edmProperty.Nullable)                    required="[Required(ErrorMessage = /"请输入{0}/")]";                string facetName = "MaxLength";                var lengthDes="";                var stringLengthDes="";                int maxLength = 0;                 if (code.Escape(edmProperty.TypeUsage).ToLower().Contains("string") && Int32.TryParse(edmProperty.TypeUsage.Facets[facetName].Value.ToString(), out maxLength)){                    lengthDes="[MaxLength("+maxLength+")]";                    stringLengthDes="[StringLength("+maxLength+")]";                }                var dataType="";                if (code.Escape(edmProperty.TypeUsage).ToLower().Contains("datetime"))                    dataType="[DataType(DataType.DateTime)]";                else if (edmProperty.Name.ToLower().Contains("passWord"))                    dataType="[DataType(DataType.Password)]";      #>    /// <summary>    /// <#=                    summary#>    /// </summary><#                if(!string.IsNullOrWhiteSpace(required)){ #>    <#=                        required #><#                    } if(!string.IsNullOrWhiteSpace(summary)){ #>    <#=                        "[Display(Name = /""+summary+"/")]" #><#                    } if(!string.IsNullOrWhiteSpace(lengthDes)){ #>    <#=                        lengthDes #><#                    } if(!string.IsNullOrWhiteSpace(stringLengthDes)){ #>    <#=                        stringLengthDes #><#                    } if(!string.IsNullOrWhiteSpace(dataType)){ #>    <#=                        dataType #><#                    } if(!string.IsNullOrWhiteSpace(keyName)){ #>    <#=                        keyName #><#                } #>    <#=codeStringGenerator.Property(edmProperty)#>

效果基本已经差不多，可是这里为什么没有注释，园子里已经有其他文章来处理这个问题：

1.0EF架构~将数据库注释添加导入到模型实体类中 2.0entity framework框架生成摘要文档为空(没有元数据文档可用)的bug解决方案

按照步骤做了，可是问题还是没有解决，怎么办，其实根本原因是：

主要原因是这里的摘要没有数据。不断的尝试啊，entity framework框架生成摘要文档为空(没有元数据文档可用)的bug解决方案试了几次还是没有从根本上解决问题，怎么办了...

3.0解决bug

没办法我们查看EFTSQLDocumentation.Generator的源码终于找到问题所在

        public String ConnectionString { get; set; }        public String InputFileName { get; set; }        public String OutputFileName { get; set; }        private SqlConnection _connection;        public Program(String connectionString, String inputFileName, String outputFileName)        {            this.ConnectionString = connectionString;            this.InputFileName = inputFileName;            this.OutputFileName = outputFileName;            this._connection = new SqlConnection(connectionString);            this._connection.Open();        }        public void Dispose()        {            this._connection.Dispose();        }        private void CreateDocumentation()        {            XDocument doc = XDocument.Load(this.InputFileName);            IEnumerable<XElement> entityTypeElements = doc.Descendants("{http://schemas.microsoft.com/ado/2008/09/edm}EntityType");            int i = 0;            foreach (XElement entityTypeElement in entityTypeElements)            {                String tableName = entityTypeElement.Attribute("Name").Value;                IEnumerable<XElement> propertyElements = entityTypeElement.Descendants("{http://schemas.microsoft.com/ado/2008/09/edm}Property");                Console.Clear();                Console.WriteLine("Analyzing table {0} of {1}", i++, entityTypeElements.Count());                Console.WriteLine(" => TableName : {0}" +                                  "/n => property count : {1}", tableName, propertyElements.Count());                this.AddNodeDocumentation(entityTypeElement, GetTableDocumentation(tableName));                foreach (XElement propertyElement in propertyElements)                {                    String columnName = propertyElement.Attribute("Name").Value;                    this.AddNodeDocumentation(propertyElement, GetColumnDocumentation(tableName, columnName));                }            }            Console.WriteLine("Writing result to {0}", this.OutputFileName);            if (File.Exists(this.OutputFileName))                File.Delete(this.OutputFileName);            doc.Save(this.OutputFileName);        }        private void AddNodeDocumentation(XElement element, String documentation)        {            if (String.IsNullOrEmpty(documentation))                return;            element.Descendants("{http://schemas.microsoft.com/ado/2008/09/edm}Documentation").Remove();            element.AddFirst(new XElement("{http://schemas.microsoft.com/ado/2008/09/edm}Documentation", new XElement("{http://schemas.microsoft.com/ado/2008/09/edm}Summary", documentation)));        }        private String GetTableDocumentation(String tableName)        {            using (SqlCommand command = new SqlCommand(@" SELECT [value]                                                           FROM fn_listextendedproperty (                                                                'MS_Description',                                                                 'schema', 'dbo',                                                                 'table',  @TableName,                                                                 null, null)", this._connection))            {                command.Parameters.AddWithValue("TableName", tableName);                return command.ExecuteScalar() as String;            }        }        private String GetColumnDocumentation(String tableName, String columnName)        {            using (SqlCommand command = new SqlCommand(@"SELECT [value]                                                          FROM fn_listextendedproperty (                                                                'MS_Description',                                                                 'schema', 'dbo',                                                                 'table', @TableName,                                                                 'column', @columnName)", this._connection))            {                command.Parameters.AddWithValue("TableName", tableName);                command.Parameters.AddWithValue("ColumnName", columnName);                return command.ExecuteScalar() as String;            }        }

我们的edmx中的代码如下:

      <Schema Namespace="yaochufaNewTestModel.Store" Provider="System.Data.SqlClient" ProviderManifestToken="2008" Alias="Self" xmlns:store="http://schemas.microsoft.com/ado/2007/12/edm/EntityStoreSchemaGenerator" xmlns:customannotation="http://schemas.microsoft.com/ado/2013/11/edm/customannotation" xmlns="http://schemas.microsoft.com/ado/2009/11/edm/ssdl">        <EntityType Name="Activities">          <Key>            <PropertyRef Name="ActivityId" />          </Key>          <Property Name="ActivityId" Type="int" StoreGeneratedPattern="Identity" Nullable="false" />          <Property Name="ActivityType" Type="int" Nullable="false" />          <Property Name="ProvinceId" Type="int" />          <Property Name="CityId" Type="int" />          <Property Name="Description" Type="nvarchar" MaxLength="50" />          <Property Name="IsActive" Type="bit" Nullable="false" />          <Property Name="EndDate" Type="datetime" />          <Property Name="StartDate" Type="datetime" />          <Property Name="DrawDate" Type="datetime" />          <Property Name="DrawInfo" Type="nvarchar" MaxLength="1000" />          <Property Name="LimitTime" Type="int" />          <Property Name="ShowStartDate" Type="datetime" />          <Property Name="ShowEndDate" Type="datetime" />          <Property Name="PrizeCount" Type="int" />          <Property Name="ModifiedById" Type="int" />          <Property Name="ModifiedByName" Type="nvarchar" MaxLength="50" />          <Property Name="ModifiedDate" Type="datetime" />          <Property Name="CreatedById" Type="int" Nullable="false" />          <Property Name="CreatedByName" Type="nvarchar" MaxLength="50" Nullable="false" />          <Property Name="CreatedDate" Type="datetime" Nullable="false" />        </EntityType>

需要修改的就是EFTSQLDocumentation.Generator源码中的xml命名空间我们要替换成 http://schemas.microsoft.com/ado/2009/11/edm最终在cmd中运行如下代码：

EFTSQLDocumentation.Generator.exe -c "data source=.;initial catalog=yaochufaNewTest;user id=sa;password=123;" -i " D:/Feng.Test/Feng.Test/Model1.edmx"

得到效果图如下：