可选参数无法正常工作

Question

我有一个方法,可以选择最后一个参数.

public static DataTable GetQueryResult<T>(string connectionString, string queryText, Dictionary<string, T> dicParameters = null)

当我尝试调用此方法时:

DBOperations.GetQueryResult(myConnectionString, myQuery);

它说方法'GetQueryResult'没有重载需要2个参数.

本文档解释了我只能将所需的参数传递给这种方法.

问候

Answer 1

您必须明确指定T:

DBOperations.GetQueryResult<YourType>(myConnectionString, myQuery);

指定时dicParameters,T隐式:

var dicParameters = new Dictionary<string, YourType>();
DBOperations.GetQueryResult(myConnectionString, myQuery, dicParameters );