Question

我正在visual studio 2012上构建一个基于桌面的应用程序。实体框架无法正常工作SaveChanges()出现它不会出现异常，似乎已输入数据但刷新数据库后没有添加额外的行在它。

对于演示，我制作了2层架构。

查看
数据访问层

我的观点是......

    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }

        private void button1_Click(object sender, EventArgs e)
        {
            MyDAL dal = new MyDAL();
            if (dal.Add(StudentName.Text, Contact.Text))
            {
                MessageBox.Show("Addition Successfull");
            }
            else
            {
                MessageBox.Show("Addition Failed");
            }
        }
    }

我的数据访问层........

    public class MyDAL
    {
        public bool Add(string name, string contact)
        {
            using (var db = new Database1Entities())
            {
                Student s = new Student();
                s.StudentName = name;
                s.ContactNo = contact;

                try
                {
                    db.Students.Add(s);
                    db.SaveChanges();
                    return true;
                }
                catch (Exception ex)
                {
                    return false;
                }
            }
        }
    }

我的数据库脚本是.....

CREATE TABLE [dbo].[Student] (
    [Student_Id]  INT          IDENTITY (1, 1) NOT NULL,
    [StudentName] VARCHAR (50) NULL,
    [ContactNo]   VARCHAR (50) NULL,
    PRIMARY KEY CLUSTERED ([Student_Id] ASC)
);

我的App.Config in View

<?xml version="1.0" encoding="utf-8" ?>
<configuration>
  <startup>
    <supportedRuntime version="v4.0" sku=".NETFramework,Version=v4.5" />
  </startup>
  <connectionStrings>
    <add name="Database1Entities" connectionString="metadata=res://*/Model1.csdl|res://*/Model1.ssdl|res://*/Model1.msl;provider=System.Data.SqlClient;provider connection string=&quot;data source=(LocalDB)\v11.0;attachdbfilename=|DataDirectory|\Database1.mdf;integrated security=True;connect timeout=30;MultipleActiveResultSets=True;App=EntityFramework&quot;" providerName="System.Data.EntityClient" />
  </connectionStrings>
</configuration>

我在DAL的App.Config是......

<?xml version="1.0" encoding="utf-8"?>
<configuration>
  <configSections>
    <!-- For more information on Entity Framework configuration, visit http://go.microsoft.com/fwlink/?LinkID=237468 -->
    <section name="entityFramework" type="System.Data.Entity.Internal.ConfigFile.EntityFrameworkSection, EntityFramework, Version=5.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089" requirePermission="false" />
  </configSections>
  <connectionStrings>
    <add name="Database1Entities" connectionString="metadata=res://*/Model1.csdl|res://*/Model1.ssdl|res://*/Model1.msl;provider=System.Data.SqlClient;provider connection string=&quot;data source=(LocalDB)\v11.0;attachdbfilename=|DataDirectory|\Database1.mdf;integrated security=True;connect timeout=30;MultipleActiveResultSets=True;App=EntityFramework&quot;" providerName="System.Data.EntityClient" />
  </connectionStrings>
  <entityFramework>
    <defaultConnectionFactory type="System.Data.Entity.Infrastructure.LocalDbConnectionFactory, EntityFramework">
      <parameters>
        <parameter value="v11.0" />
      </parameters>
    </defaultConnectionFactory>
  </entityFramework>
</configuration>

Answer 1

它按预期工作。这是对|DataDirectory|选项的简单误解。

编译解决方案时，数据库正被复制到\Debug\|DataDirectory|，并且文件正在被修改。

您很可能正在查看解决方案（visual studio）中的文件，该文件 not 正被Debug目录中的可执行文件修改。

实体框架不适用于N层架构

1 个答案: