'BO.Bo._Name'永远不会被赋值，并且它的默认值是null，它是什么？ [英] 'BO.Bo._Name' is never assigned to, and will always have its default value null what is it?

问题描述

BusinessObjects中的代码

Code in BusinessObjects

public class Bo
   {
       private string _Name;
       private string _Address;
       private string _Phone;
       public string Name
       {
           set { value = _Name; }
           get { return _Name; }
       }
       public string Address
       {
           set { value = _Address; }
           get { return _Address; }
       }
       public string Phone
       {
           set { value = _Phone; }
           get { return _Phone; }
       }
   }

BUsiness逻辑层中的代码

Code in BUsiness Logic Layer

public class Bll
   {
      public void insertstudent(Bo objbo)
      {
          Dal objdal = new Dal();
          objdal.insertstudentdetails(objbo);
      }
   }

DataAccessLayer中的代码

Code in DataAccessLayer

string cs = ConfigurationManager.ConnectionStrings["DBCS"].ConnectionString;
public void insertstudentdetails(Bo objbo)
{
    using (SqlConnection con = new SqlConnection(cs))
    {
        using (SqlCommand cmd = new SqlCommand("spinserttblstudent", con))
        {
            cmd.CommandType = CommandType.StoredProcedure;
            cmd.Parameters.AddWithValue("@Name",objbo.Name);
            cmd.Parameters.AddWithValue("@Address",objbo.Address);
            cmd.Parameters.AddWithValue("@Phone", objbo.Phone);
            con.Open();
            cmd.ExecuteNonQuery();
            cmd.Dispose();
        }

    }
}

代码隐藏在文件背后



protected void btninsert_Click（object sender，EventArgs e）

{

Bo objbo = new Bo（）;

objbo.Name = txtname.Text;

objbo.Address = txtaddress.Text;

objbo.Phone = txtphone.Text;

Bll objbll = new Bll（）;

objbll.insertstudent（objbo）;



}



当我构建应用程序时，我得到编译错误说明





D：\\ \\ today3-tier \ WebApplication1 \ BO\Bo.cs（10,24）：警告CS0649：字段'BO.Bo._Name'永远不会分配给，并且将始终具有其默认值null

D：\today3-tier \WebApplication1 \ BO\Bo.cs（11,24）：警告CS0649：从未分配字段'BO.Bo._Address'，并且将始终具有其默认值null

D：\today3-tier\WebApplication1\BO\Bo.cs（12,24）：警告CS0649：字段'BO.Bo._PhoneNumber '永远不会被赋予，并且总是将其默认值为null



如何摆脱它们是什么意思？

code in code behind file

protected void btninsert_Click(object sender, EventArgs e)
{
Bo objbo = new Bo();
objbo.Name = txtname.Text;
objbo.Address = txtaddress.Text;
objbo.Phone = txtphone.Text;
Bll objbll = new Bll();
objbll.insertstudent(objbo);

}

When i build the application i'am getting compilation error stating that


D:\today3-tier\WebApplication1\BO\Bo.cs(10,24): warning CS0649: Field 'BO.Bo._Name' is never assigned to, and will always have its default value null
D:\today3-tier\WebApplication1\BO\Bo.cs(11,24): warning CS0649: Field 'BO.Bo._Address' is never assigned to, and will always have its default value null
D:\today3-tier\WebApplication1\BO\Bo.cs(12,24): warning CS0649: Field 'BO.Bo._PhoneNumber' is never assigned to, and will always have its default value null

What does it mean how to get rid of them?

推荐答案

您需要更改以下属性的设置者

you need to change the setter of your properties as below

public string Name
{
    set { _Name = value; }
    get { return _Name; }
}
public string Address
{
    set { _Address= value; }
    get { return _Address; }
}
public string Phone
{
    set { _Phone= value; }
    get { return _Phone; }
}

check 属性教程 [ ^ ]

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