EntityFramework4的POCO模板生成FunctionImport返回空的服务端调用代码

比眉伴天荒 2022-04-01 15:23 49阅读 0赞

我们知道[Entity Framework][] 4 默认根据MODEL生成ServerCode, 现在我们使用POCO T4模板。有个小问题，对于那些[Function Import][]的存储过程没有返回值，却没有生成相应的CODE。主要生成于一个DataContext下，通常是XXXXX.Context.tt的模板。打开模板，你可以找到这么一行代码：

if (edmFunction.ReturnParameter == null)

就是这里了，接下我们自己来修改一下。最后修改完后，如下：

//*********************************************************

//    This code is licensed under the Microsoft Public License.

//    THIS CODE IS PROVIDED *AS IS* WITHOUT WARRANTY OF

//    ANY KIND, EITHER EXPRESS OR IMPLIED, INCLUDING ANY

//    IMPLIED WARRANTIES OF FITNESS FOR A PARTICULAR

//    PURPOSE, MERCHANTABILITY, OR NON-INFRINGEMENT.

//*********************************************************

<#@ template language="C#" debug="false" hostspecific="true"#>

<#@ include file="EF.Utility.CS.ttinclude"#><#@

output extension=".cs"#><#

CodeGenerationTools code = new CodeGenerationTools(this);

MetadataTools ef = new MetadataTools(this);

MetadataLoader loader = new MetadataLoader(this);

CodeRegion region = new CodeRegion(this);

string inputFile = @"model.edmx";

EdmItemCollection ItemCollection = loader.CreateEdmItemCollection(inputFile);

string namespaceName = code.VsNamespaceSuggestion();

EntityContainer container = ItemCollection.GetItems<EntityContainer>().FirstOrDefault();

if (container == null)

{

return "// No EntityContainer exists in the model, so no code was generated";

}

//------------------------------------------------------------------------------

// <auto-generated>

//     This code was generated from a template.

//     Changes to this file may cause incorrect behavior and will be lost if

//     the code is regenerated.

// </auto-generated>

//------------------------------------------------------------------------------

using System;

using System.Data.Objects;

using System.Data.EntityClient;

if (!String.IsNullOrEmpty(namespaceName))

{

namespace <#=code.EscapeNamespace(namespaceName)#>

{

PushIndent(CodeRegion.GetIndent(1));

}

<#=Accessibility.ForType(container)#> partial class <#=code.Escape(container)#> : ObjectContext

{

public const string ConnectionString = "name=<#=container.Name#>";

public const string ContainerName = "<#=container.Name#>";

#region Constructors

public <#=code.Escape(container)#>()

: base(ConnectionString, ContainerName)

{

WriteLazyLoadingEnabled(container);

}

public <#=code.Escape(container)#>(string connectionString)

: base(connectionString, ContainerName)

{

WriteLazyLoadingEnabled(container);

}

public <#=code.Escape(container)#>(EntityConnection connection)

: base(connection, ContainerName)

{

WriteLazyLoadingEnabled(container);

}

#endregion

region.Begin("ObjectSet Properties", 2);

foreach (EntitySet entitySet in container.BaseEntitySets.OfType<EntitySet>())

{

<#=Accessibility.ForReadOnlyProperty(entitySet)#> ObjectSet<<#=code.Escape(entitySet.ElementType)#>> <#=code.Escape(entitySet)#>

{

get { return <#=code.FieldName(entitySet) #>  ?? (<#=code.FieldName(entitySet)#> = CreateObjectSet<<#=code.Escape(entitySet.ElementType)#>>("<#=entitySet.Name#>")); }

}

private ObjectSet<<#=code.Escape(entitySet.ElementType)#>> <#=code.FieldName(entitySet)#>;

}

region.End();

region.Begin("Function Imports");

foreach (EdmFunction edmFunction in container.FunctionImports)

{

var parameters = FunctionImportParameter.Create(edmFunction.Parameters, code, ef);

string paramList = String.Join(", ", parameters.Select(p => p.FunctionParameterType + " " + p.FunctionParameterName).ToArray());

string returnTypeElement = "int";

if (edmFunction.ReturnParameter == null)

{

<#=Accessibility.ForMethod(edmFunction)#> void <#=code.Escape(edmFunction)#>(<#=paramList#>)

{

}

else

{

returnTypeElement = code.Escape(ef.GetElementType(edmFunction.ReturnParameter.TypeUsage));

<#=Accessibility.ForMethod(edmFunction)#> ObjectResult<<#=returnTypeElement#>> <#=code.Escape(edmFunction)#>(<#=paramList#>)

{

}

foreach (var parameter in parameters)

{

if (!parameter.NeedsLocalVariable)

{

continue;

}

ObjectParameter <#=parameter.LocalVariableName#>;

if (<#=parameter.IsNullableOfT ? parameter.FunctionParameterName + ".HasValue" : parameter.FunctionParameterName + " != null"#>)

{

<#=parameter.LocalVariableName#> = new ObjectParameter("<#=parameter.EsqlParameterName#>", <#=parameter.FunctionParameterName#>);

}

else

{

<#=parameter.LocalVariableName#> = new ObjectParameter("<#=parameter.EsqlParameterName#>", typeof(<#=parameter.RawClrTypeName#>));

}

if (edmFunction.ReturnParameter == null)

{

base.ExecuteFunction("<#=edmFunction.Name#>"<#=code.StringBefore(", ", String.Join(", ", parameters.Select(p => p.ExecuteParameterName).ToArray()))#>);

}

else

{

return base.ExecuteFunction<<#=returnTypeElement#>>("<#=edmFunction.Name#>"<#=code.StringBefore(", ", String.Join(", ", parameters.Select(p => p.ExecuteParameterName).ToArray()))#>);

}

region.End();

}

if (!String.IsNullOrEmpty(namespaceName))

{

PopIndent();

}

<#+

private void WriteLazyLoadingEnabled(EntityContainer container)

{

string lazyLoadingAttributeValue = null;

string lazyLoadingAttributeName = MetadataConstants.EDM_ANNOTATION_09_02 + ":LazyLoadingEnabled";

if(MetadataTools.TryGetStringMetadataPropertySetting(container, lazyLoadingAttributeName, out lazyLoadingAttributeValue))

{

bool isLazyLoading = false;

if(bool.TryParse(lazyLoadingAttributeValue, out isLazyLoading))

{

this.ContextOptions.LazyLoadingEnabled = <#=isLazyLoading.ToString().ToLowerInvariant()#>;

<#+

}

把那个inputfile变量的值替换成你的edmx，就可以使用了。将生成这样的代码，注意这个方法返回是void:

1:      public partial class Entities : ObjectContext

2:      {

4:          public void ChangeForumID(string thread, Nullable<int> forum)

5:          {

6:              ObjectParameter threadParameter;

7:              if (thread != null)

8:              {

9:                  threadParameter = new ObjectParameter("Thread", thread);

10:              }

11:              else

12:              {

13:                  threadParameter = new ObjectParameter("Thread", typeof(string));

14:              }

15:

16:              ObjectParameter forumParameter;

17:              if (forum.HasValue)

18:              {

19:                  forumParameter = new ObjectParameter("Forum", forum);

20:              }

21:              else

22:              {

23:                  forumParameter = new ObjectParameter("Forum", typeof(int));

24:              }

25:

26:              base.ExecuteFunction("ChangeForumID", threadParameter, forumParameter);

27:          }

28:

当然你手写也是可以的，不过数量多就很累了。希望这篇POST对您开发有帮助。

作者：[Petter Liu][]  
出处：[http://www.cnblogs.com/wintersun/][Petter Liu]  
本文版权归作者和博客园共有，欢迎转载，但未经作者同意必须保留此段声明，且在文章页面明显位置给出原文连接，否则保留追究法律责任的权利。  
该文章也同时发布在我的独立博客中-[Petter Liu Blog][Petter Liu]。

[Entity Framework]: http://msdn.microsoft.com/en-us/library/aa697427%28VS.80%29.aspx
[Function Import]: http://msdn.microsoft.com/en-us/library/bb896231.aspx
[Petter Liu]: http://www.cnblogs.com/wintersun/