我不确定在代码中调用激活器之前是否/如何检查构造函数实际存在(未经测试,因此可能有错误但希望其意图清晰)。如何错误检查此工厂创建<T>使用参数激活器的方法?
它就好像我想要一个模板约束,它说“哪里T有一个带签名S的构造函数”。
public class EntityContainerFactory
{
public EntityContainerFactory(string sqlServerName, string databaseName, string metaData)
: this(sqlServerName, databaseName, metaData, "System.Data.EntityClient")
{
}
public EntityContainerFactory(string sqlServerName, string databaseName, string metaData, string dataProviderName)
{
SqlServerName = sqlServerName;
DatabaseName = databaseName;
Metadata = metaData;
DataProviderName = dataProviderName;
}
// --> IS THERE ANY WAY TO CHECK THAT T HAS
// A CONSTRUCTOR THAT TAKES AN ENTITY CONNECTION?
public T Create<T>()
{
return (T)Activator.CreateInstance(typeof(T), CreateEntityConnection());
}
EntityConnection CreateEntityConnection()
{
SqlConnectionStringBuilder sqlBuilder = new SqlConnectionStringBuilder();
sqlBuilder.DataSource = SqlServerName;
sqlBuilder.InitialCatalog = DatabaseName;
sqlBuilder.IntegratedSecurity = true;
EntityConnectionStringBuilder entityBuilder = new EntityConnectionStringBuilder();
entityBuilder.Provider = DataProviderName;
entityBuilder.ProviderConnectionString = sqlBuilder.ToString();
entityBuilder.Metadata = Metadata;
return new EntityConnection(entityBuilder.ConnectionString);
}
public string DatabaseName { get; set; }
public string SqlServerName { get; set; }
public string DataProviderName { get; set; }
private string metaData;
public string Metadata
{
get
{
string result;
if (!this.metaData.StartsWith("res://"))
{
result = string.Format(@"res://*/{0}.csdl|res://*/{0}.ssdl|res://*/{0}.msl", this.metaData);
}
else
{
result = this.metaData;
}
return result;
}
set
{
this.metaData = value;
}
}
}
请花时间粘贴相关代码,而不是整块或全班。 – 2012-02-09 22:36:27