如何放置两个DataValueFields？

如何绑定产品名称，然后在标签结果中获取产品ID和价格？这三个属性来自DB中的同一个表。如何放置两个DataValueFields？

代码：

public partial class CreateOrder : System.Web.UI.Page 
{ 
    protected void Page_Load(object sender, EventArgs e) 
    { 
     if (Page.IsPostBack == false) bindListBox(); 
    } 
} 

private void bindListBox() 
{ 
    ddlProduct.DataSource  = getReader(); 
    ddlProduct.DataTextField = "productName"; 
    ddlProduct.DataValueField = "IDANDPRICE"; 

    ddlProduct.DataBind(); 
} 

private SqlDataReader getReader() 
{ 
    //get connection string from web.config 
    string strConnectionString = 
     ConfigurationManager.ConnectionStrings["ConnectionString"].ConnectionString; 
    SqlConnection myConnect = new SqlConnection(strConnectionString); 

    string strCommandText = "SELECT productName, productID,productPrice,(productID + '-' + productPrice) AS IDANDPRICE from Product"; 
    SqlCommand cmd = new SqlCommand(strCommandText, myConnect); 

    myConnect.Open(); 

    SqlDataReader reader = cmd.ExecuteReader(CommandBehavior.CloseConnection); 
    return reader; 
} 

protected void DropDownList2_SelectedIndexChanged(object sender, EventArgs e) 
{ 
    Label1.Text = ""; 
    Label1.Text += "productName:" + ddlProduct.SelectedItem.Text + "<br/>"; 

    Label2.Text = ""; 
    Label2.Text += "IDANDPRICE:" + ddlProduct.SelectedItem.ToString() ; 

}

来源

2016-01-02 chingggg

读取器是一个枚举对象。您必须使用Read（）方法来获取可枚举对象的每一行。使用SqlDataAdapter并将结果放入DataTable中更好。然后将您的控件绑定到DataTable。 – jdweng

做一个大忙，并使用ORM（如实体框架）从数据库中获取*对象*。这会让你的生活更轻松。您可以将一系列'Product'对象绑定到DDL并使用SelectedItem。 –

 
I find the following errors: 

1- cast number filed to nvarchar in sql query 
2- set AutoPostBack property of listbox to true 
3- use ddlProduct.SelectedItem.Value for label2

我创建了一个页面，并使用你的代码，并应用上面的建议，下面的代码工作完美。

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

protected void Page_Load(object sender, EventArgs e) 
{ 
    if (Page.IsPostBack == false) bindListBox(); 
} 

private void bindListBox() 
{ 
    ddlProduct.DataSource = getReader(); 
    ddlProduct.DataTextField = "name"; 
    ddlProduct.DataValueField = "IdAndName"; 

    ddlProduct.DataBind(); 
} 

private SqlDataReader getReader() 
{ 
    //get connection string from web.config 
    string strConnectionString = ConfigurationManager.ConnectionStrings["ConnectionString"].ConnectionString; 
    SqlConnection myConnect = new SqlConnection(strConnectionString); 

    string strCommandText = "SELECT Id,Name,CAST(id as nvarchar(10))+'-'+Name as IdAndName FROM Product"; 
    SqlCommand cmd = new SqlCommand(strCommandText, myConnect); 

    myConnect.Open(); 

    SqlDataReader reader = cmd.ExecuteReader(CommandBehavior.CloseConnection); 
    return reader; 
} 

protected void DropDownList2_SelectedIndexChanged(object sender, EventArgs e) 
{ 
    Label1.Text = ""; 
    Label1.Text += "productName:" + ddlProduct.SelectedItem.Text + "<br/>"; 

    Label2.Text = ""; 
    Label2.Text += "IDANDPRICE:" + ddlProduct.SelectedItem.Value; 
} 

}

来源

2016-02-14 13:44:05 Bashir

如何放置两个DataValueFields？

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