Question

朋友们过去一周我一直在工作WCF。我写了一些样本，它包含2层，一层是业务层和一层DAL层。我想发送列表并希望返回列表。

这是代码检查纠正错误。

IEmployee.cs

 [OperationContract]
 List<outEmployee> CreateEmployeeDetails(inemployee InsertEmployee);

 [DataContract]
 public class inemployee
 {
    public string EmployeeID { get; set; }
    public string EmployeeName { get; set; }    
 }

 public class outEmailTemplate
 {
    public string EmployeeID { get; set; }
    public string EmployeeName { get; set; }
 }

Employee.svc.cs

 public List<outEmployee> CreateEmployeeDetails(inemployee InsertEmployee)
 {
    EmployeeDac emp = new EmployeeDac();
    return emp.InsertEmployeeDetails(InsertEmployee);
 }

EmployeeDac.cs

public List<outEmployee> InsertEmailTemplate(inEmployee InsertEmp)
{
    SqlConnection con = new SqlConnection(connectionstring);
    SqlCommand cmd;
    cmd = new SqlCommand("SP_InsertEmployee", con);
    cmd.CommandType = CommandType.StoredProcedure;
    cmd.Parameters.Add("employeename", SqlDbType.VarChar).Value = InsertEmp.Employeename;
    con.Open();
    string id = (string)cmd.ExecuteScalar();
    con.Close();
    List<inemployee> oet = new List<inemployee>();
    oet.Add(id);
    return oet;
 }

任何人都可以纠正错误并重写代码。

这里我想将列表返回给ui（silverlight）。

Answer 1

几个问题：

1）数据合同不完整 - 首先需要修饰服务方法中使用的所有类（输入和使用[DataContract]输出参数！），你还应该用[DataMember]装饰要序列化的所有成员：

    [DataContract]
    public class inemployee
    {
       [DataMember]
       public string EmployeeID { get; set; }
       [DataMember]
       public string EmployeeName { get; set; }    
    }

    [DataContract]
    public class outemployee
    {
       [DataMember]
       public string EmployeeID { get; set; }
       [DataMember]
       public string EmployeeName { get; set; }
    }

BTW：为什么你有两种不同的类型 - inemployee和outemployee ??不只是一种Employee就足够了吗？

2）您的DAL图层应该采用最佳做法：将SqlConnection和SqlCommand包装成使用块;对于VARCHAR参数，始终定义长度！最重要的是：如果你想返回List<outemployee>，你需要创建一个outemployee的列表 - 而不是inemployee！

要结束：您正在返回id类型string并且您尝试将string添加到List<outemployee> - 这将<强大>从不当然是工作！鉴于id，您需要创建outemployee的实例，并将添加到列表中。

    public List<outEmployee> InsertEmailTemplate(inEmployee InsertEmp)
    {
        using(SqlConnection con = new SqlConnection(connectionstring))
        using(SqlCommand cmd = new SqlCommand("SP_InsertEmployee", con))
        {
           cmd.CommandType = CommandType.StoredProcedure;
           cmd.Parameters.Add("employeename", SqlDbType.VarChar, 100).Value = InsertEmp.Employeename;

           con.Open();
           string id = (string)cmd.ExecuteScalar();
           con.Close();
        }

        // you want to return outemployee - 
        // so you need to create an outemployee!
        List<outemployee> oet = new List<outemployee>(); 

        // create a new instance of an "outemployee"
        outemployee emp = new outemployee();

        // set the EmployeeID property of the "outemployee" to "id"
        emp.EmployeeID = id;

        // add new "outemployee" to list
        oet.Add(emp);

        return oet;
    }

WCF中的转换和返回列表

1 个答案: