Dropdownlist选项不会更改数据

Question

我的dropdownlist不工作​​，为什么我想要它，我不明白为什么。我已经通过stackoverflow看，我找不到与我的相应的问题。我的下拉列表显示数据库中的所有名称，但当选择名称时，附加到数据库中名称的数据不会显示在文本框中。名字的数据在文本框中正确加载，但之后数据不会改变。当涉及到datasouceselect代码时，我必须做错误的事情。这是我的代码。

using System; 
using System.Collections.Generic; 
using System.Linq; 
using System.Web; 
using System.Web.UI; 
using System.Web.UI.WebControls; 
using System.Data; 
using System.Data.SqlClient; 

public partial class Contact : System.Web.UI.Page 
{ 

    private EmployeeContact selectedContact; 

    protected void Page_Load(object sender, EventArgs e) 
    { 
     // if it is not a PostBack, 
     // then bind the Employee data to the ddlContact dropdown list 
     if (!IsPostBack) DropDownList1.DataBind(); 
     // Store the Contact data in the selectedContact object  
     selectedContact = this.GetselectedContact(); 
     // Display the ContactID from the object in the txtContactID.Text  
     txtContactID.Text = selectedContact.ContactID; 
     // Display the Name from the object in the txtFirst.Text 
     txtFirst.Text = selectedContact.Contact_FirstName; 
     // Display the Street from the object in the txtLast.Text 
     txtLast.Text = selectedContact.Contact_LastName; 
     // Display the City from the object in the txtCell.Text 
     txtCell.Text = selectedContact.Contact_Cell; 
     // Display the State from the object in the txtOfficePhone.Text 
     txtOfficePhone.Text = selectedContact.Contact_OfficePhone; 
     // Display the Zip from the object in the txtEmail.Text 
     txtEmail.Text = selectedContact.Contact_Email; 
     // Display the Phone from the object in the txtPhone.Text 
     txtCompany.Text = selectedContact.Contact_Company; 
     // Display the Email from the object in the txtPosition.Text 
     txtPosition.Text = selectedContact.Contact_Position; 
     // Display the Phone from the object in the txtZip.Text 
     txtZip.Text = selectedContact.Contact_Zip; 
     // Display the Phone from the object in the txtStreet.Text 
     txtStreet.Text = selectedContact.Contact_Street; 
     // Display the Phone from the object in the txtCustomerSince.Text 
     txtCustomerSince.Text = selectedContact.Contact_CustomerSinceDate; 
     // Display the Phone from the object in the txtDateCreated.Text 
     txtDateCreated.Text = selectedContact.Contact_DateCreated; 
     // Display the Phone from the object in the txtNotes.Text 
     txtNotes.Text = selectedContact.Contact_Note; 
    } 

    private EmployeeContact GetselectedContact() 
    { 
     // Use DataView to get a datatable 
     DataView Contacts = (DataView)SqlDataSource1.Select(DataSourceSelectArguments.Empty); 
     // Format a RowFilter   
     Contacts.RowFilter = string.Format("ContactID = '{0}'", DropDownList1.SelectedValue); 
     // Get a specific row from the selected customer table row 
     DataRowView row = (DataRowView)Contacts[0]; 
     // Instantiate a EmployeeContact object 
     EmployeeContact c = new EmployeeContact(); 
     // Store the ContactID in the object 
     c.ContactID = row["ContactID"].ToString(); 
     // Store the FirstName in the object 
     c.Contact_FirstName = row["Contact_FirstName"].ToString(); 
     // Store the LastName in the object 
     c.Contact_LastName = row["Contact_LastName"].ToString(); 
     // Store the Cellphone in the object 
     c.Contact_Cell = row["Contact_Cell"].ToString(); 
     // Store the OfficePhone in the object 
     c.Contact_OfficePhone = row["Contact_OfficePhone"].ToString(); 
     // Store the Email in the object 
     c.Contact_Email = row["Contact_Email"].ToString(); 
     // Store the Company in the object, 
     c.Contact_Company = row["Contact_Company"].ToString(); 
     // Store the Position in the object, 
     c.Contact_Position = row["Contact_Position"].ToString(); 
     // Store the Street in the object, 
     c.Contact_Street = row["Contact_Street"].ToString(); 
     // Store the Zip in the object 
     c.Contact_Zip = row["Contact_Zip"].ToString(); 
     // Store the CustomerSinceDate in the object 
     c.Contact_CustomerSinceDate = row["Contact_CustomerSinceDate"].ToString(); 
     // Store the DateCreated in the object 
     c.Contact_DateCreated = row["Contact_DateCreated"].ToString(); 
     // Store the Notes in the object 
     c.Contact_Note = row["Contact_Note"].ToString(); 
     // Return the object  
     return c; 



    } 

} 

谢谢

Answer 1

确保您处理下拉列表选择“OnSelectedIndexChanged”事件处理程序中改变代码。

而且，似乎使用ContactID列是一个数字int或类似的东西，如果是这样，请确保您从该行删除单引号：

Contacts.RowFilter = string.Format("ContactID = '{0}'", DropDownList1.SelectedValue); 

是：

Contacts.RowFilter = string.Format("ContactID = {0}", DropDownList1.SelectedValue); 

希望它有帮助。