[原创]EF架构随心所欲打造属于你自己的DbModel

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 = ;
                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 = ;
            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="" 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="" />
          <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="" />
          <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="" />
          <Property Name="ModifiedDate" Type="datetime" />
          <Property Name="CreatedById" Type="int" Nullable="false" />
          <Property Name="CreatedByName" Type="nvarchar" MaxLength="" 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：