您在代码中使用了其他名称作为参数.尝试更改

You're using a different name for the parameter in your code. Try changing

ename.ParameterName = "ename";

到

ename.ParameterName = "P_ename";

ALSO

您需要为输出值添加一个参数:

You need to add a parameter for the output value:

OracleParameter result = new OracleParameter();
result.OracleType = OracleType.VarChar;
result.Direction = ParameterDirection.ReturnValue;
orclCmnd.Parameters.Add(result);

使用ExecuteNonQuery调用函数后，从参数中获取值:

And get the value from the parameter after calling the function with ExecuteNonQuery:

orclCmnd.ExecuteNonQuery();
strResult = result.Value.ToString();