更新在Linq不提交更改（）

Question

我有代碼填充文本框，當我從ddl中選擇它們。 這工作很好，並在我的頁面加載方法。

 protected void Page_Load(object sender, EventArgs e) 
    { 
     //drp_Customer.ClearSelection(); 


     using (CustomerDataContext obj = new CustomerDataContext()) 
     { 
      // Get fields for drp_Customer 
      // =========================== 
      var allCustomers = from c in obj.Customers 
           orderby c.FirstName 
           select new 
           { 
            c.FirstName, 
            c.CustomerId 
           }; 

      drp_Customer.DataTextField = "FirstName"; 
      drp_Customer.DataValueField = "CustomerId"; 
      drp_Customer.DataSource = allCustomers.ToList(); 
      drp_Customer.DataBind(); 

      if (drp_Customer.SelectedItem.Text == " -- Select Customer -- ") 
      { 
       lbl_message.Text = "Please select a customer to update"; 
      } 
      else 
      { 
       Customer myCust = obj.Customers.SingleOrDefault(c => c.CustomerId == Convert.ToInt32(drp_Customer.SelectedItem.Value)); 

       if (myCust != null) 
       { 
        txt_FirstName.Text = myCust.FirstName; 
        txt_Surname.Text = myCust.Surname; 
        txt_HouseNumber.Text = myCust.HouseNumberName; 
        txt_Address.Text = myCust.Address; 
        txt_Town.Text = myCust.Town; 
        txt_Telephone.Text = myCust.Telephone; 
        txt_Postcode.Text = myCust.Postcode; 
       } 

      } 

     } 


    } 

我有一個用於更新，但已停止工作，因爲此代碼的頁面上更新按鈕。

 protected void btn_Update_Click(object sender, EventArgs e) 
    { 
     using (CustomerDataContext obj = new CustomerDataContext()) 
     { 
      Customer myCust = obj.Customers.SingleOrDefault(c => c.CustomerId == Convert.ToInt32(drp_Customer.SelectedValue)); 

      // Check If any are empty 
      // ====================== 
      if (myCust != null) 
      { 
       myCust.FirstName = txt_FirstName.Text; 
       myCust.Surname = txt_Surname.Text; 
       myCust.HouseNumberName = txt_HouseNumber.Text; 
       myCust.Address = txt_Address.Text; 
       myCust.Town = txt_Town.Text; 
       myCust.Telephone = txt_Telephone.Text; 
       myCust.Postcode = txt_Postcode.Text; 
      } 

      obj.SubmitChanges(); 
     } 

    } 

我查詢相同CustomerID和當我通過代碼的 // myCust.FirstName = txt_FirstName.Text步驟; 當我修改它時不會改變。

頁面是否需要刷新才能執行更改？ 或者我需要在頁面加載中以某種方式？

Answer 1

看來你正在重新加載Page_Load中的所有控件，試着在Page_Load方法中加入!Page.IsPostback。像這樣的東西：

protected void Page_Load(object sender, EventArgs e) 
{ 
    if (!Page.IsPostback) 
    { 
     //Your code goes here. 
    } 
}