/// <summary>
/// 尝试从当前上下文中获取已存在的ConnectionScope，
/// 如果没有已存在的实例，就用默认的连接字符串创建一个ConnectionScope实例
/// </summary>
/// <returns></returns>
public static ConnectionScope GetExistOrCreate()
{
ConnectionScope current = s_current;
if (current != null)
{
current._refCount++; // 增加引用计数
return(current);
}
return(Create());
}
/// <summary>
/// 通过参数化SQL、SqlParameter数组的方式，创建CPQuery实例
/// </summary>
/// <param name="parameterizedSQL">参数化的SQL字符串</param>
/// <param name="parameters">SqlParameter参数数组</param>
/// <returns>CPQuery对象实例</returns>
public static CPQuery Create(string parameterizedSQL, params DbParameter[] parameters)
{
if (string.IsNullOrEmpty(parameterizedSQL))
{
throw new ArgumentNullException("parameterizedSQL");
}
CPQuery query = new CPQuery(ConnectionScope.GetDefaultDbConext());
query.Init(parameterizedSQL, parameters);
return(query);
}
/// <summary>
/// 实现IDisposable接口
/// </summary>
public void Dispose()
{
_refCount--;
if (_refCount == 0)
{
// 恢复之前的【当前】实例
s_current = _lastInstance;
if (this.Context != null)
{
this.Context.Dispose();
this.Context = null;
}
}
}
internal static DbContext GetDefaultDbConext()
{
//return ConnectionScope.Current.Context;
ConnectionScope current = s_current;
if (current == null)
{
if (Initializer.Instance.IsAutoCreateOneOffDbContext)
{
DbContext context = DbContext.Create();
context.AutoDisposable = true;
return(context);
}
else
{
throw new InvalidProgramException("当前代码执行环境中没有创建ConnectionScope的实例");
}
}
else
{
return(current.Context);
}
}