动态改变数据库连接 in Entity Framework 5

今天把silverlight 升级到5，ADO.ENT EF也用NUGet升级到5.结果发现5下的EF默认没有4的那种分部方法了。

当然你可以把生成器的属性里面，生成代码的属性替换为default，默认为Note。也可以跟4版本一样有分部方法。

但我发现EF5下面更智能，。更好用。EF的链接字符串有相关的类

EntityConnection

可以操作了。

请参看MSDN:

http://msdn.microsoft.com/en-us/library/system.data.entityclient.entityconnection.connectionstring.aspx

这样动态改变数据库就可以变得更灵活。

只要自定义一个方法，然后返回字符串给EntityConnection链接即可

// Specify the provider name, server and database. 

string providerName = "System.Data.SqlClient";

string serverName = ".";

string databaseName = "AdventureWorks";

// Initialize the connection string builder for the 

// underlying provider.

SqlConnectionStringBuilder sqlBuilder =

    new SqlConnectionStringBuilder();

// Set the properties for the data source.

sqlBuilder.DataSource = serverName;

sqlBuilder.InitialCatalog = databaseName;

sqlBuilder.IntegratedSecurity = true;

// Build the SqlConnection connection string. 

string providerString = sqlBuilder.ToString();

// Initialize the EntityConnectionStringBuilder.

EntityConnectionStringBuilder entityBuilder =

    new EntityConnectionStringBuilder();

//Set the provider name.

entityBuilder.Provider = providerName;

// Set the provider-specific connection string.

entityBuilder.ProviderConnectionString = providerString;

// Set the Metadata location.

entityBuilder.Metadata = @"res://*/AdventureWorksModel.csdl|

                            res://*/AdventureWorksModel.ssdl|

                            res://*/AdventureWorksModel.msl";

Console.WriteLine(entityBuilder.ToString());