我是asp.net c＃的新手 我有点问题，希望有人可以帮帮我。
我想要做的是从下拉列表中使用c＃自动填充asp.net中的一些文本框，这样当他们点击列表并选择零售时，文本框将自动填充来自访问数据库
以下是我的代码到目前为止有点乱，但那是因为我还在写它。
namespace ChocoMamboAsp
{
public partial class SalesOrderForm : System.Web.UI.UserControl
{
SalesOrder _order = null;
protected void Page_Load(object sender, EventArgs e)
{
if (System.Web.HttpContext.Current.Session["SalesOrderID"] == null)
{
_order = new SalesOrder();
populateCustomerCombo();
populateEmployeeCombo();
populateProductCombo();
}
else
{
_order = new SalesOrder(long.Parse(System.Web.HttpContext.Current.Session["SalesOrderID"].ToString()));
populateCustomerCombo();
populateEmployeeCombo();
populateProductCombo();
displayRecord();
}
}
#region Mutators
/// <summary>
/// Pre-Condtion: Event Call
/// Post-Condition: calculates the item total
/// Description: Calculates the line total for each item in the grid list
/// </summary>
private void calculateLineTotal()
{
int intQty = 0;
decimal decPrice = 0.0M;
var total = 0;
foreach (GridViewRow row in dgvOrderLine.Rows)
{
var numberLabel = row.FindControl("LineTotal") as Label;
int number;
if (int.TryParse(numberLabel.Text, out number))
{
total += number;
}
}
decimal decLineTotal = decPrice * intQty;
txtSubTotal.Text = decLineTotal.ToString("c2");
calculateGrandTotal();
}
/// <summary>
/// Pre-Condtion: Events call
/// Post-Condition: Calculate the total of all the items
/// Description: This will calculate the total of all the items in the list area.
/// </summary>
private void calculateGrandTotal()
{
try
{
decimal decGrandTotal = decimal.Parse(_order.getOrderLinesTable().Compute
("Sum(LineTotal)", "").ToString());
lblTotal.Text = decGrandTotal.ToString("c2");
}
catch (FormatException)
{
//this exception will occur if tblOrderLine is empty which we can safely ignore
}
}
#endregion
protected void btnInsert_Click(object sender, EventArgs e)
{
assignChildData();
_order.OrderLineClass.addNewRecord();
calculateGrandTotal();
emptyControls();
}
#region Accessors
/// <summary>
/// Pre-Condition: Second Constructor Call
/// Post-Condition: Gettes the information from the class getters and setters
/// Description: This method gets all the information relating to the table database that has been used.
/// </summary>
private void displayRecord()
{
cboRetailer.SelectedValue = _order.RetailerID.ToString();
dtpSalesOrder.Text = _order.SalesDate.ToString();
cboSalesAgent.SelectedValue = _order.EmployeeID.ToString();
txtRetailerAddress.Text = _order.RetailerAddress;
txtRetailerPhone.Text = _order.RetailerPhone;
lblTotal.Text = _order.SaleTotal.ToString("c2");
dgvOrderLine.DataSource = _order.getOrderLinesTable();
dgvOrderLine.DataBind();
System.Diagnostics.Debug.WriteLine(_order.getOrderLinesTable());
}
/// <summary>
/// Pre-Condition: Construtor's call
/// Post-Condition:Populates the combo box with the requested information
/// Description: This method uses the method from the class in order to populate the combo box with the selcted information
/// To display one or more Items.
/// </summary>
private void populateCustomerCombo()
{
cboRetailer.DataSource = _order.getCustomers();
cboRetailer.DataValueField = "RetailerID";
cboRetailer.DataTextField = "RetailerName";
cboRetailer.DataBind();
}
/// <summary>
/// Pre-Condition: Construtor's call
/// Post-Condition:Populates the combo box with the requested information
/// Description: This method uses the method from the class in order to populate the combo box with the selcted information
/// To display one or more Items.
/// </summary>
private void populateEmployeeCombo()
{
cboSalesAgent.DataSource = _order.getEmployee();
cboSalesAgent.DataValueField = "EmployesID";
cboSalesAgent.DataTextField = "EmployeeFirstName";
cboSalesAgent.DataBind();
}
/// <summary>
/// Pre-Condition: Construtor's call
/// Post-Condition:Populates the combo box with the requested information
/// Description: This method uses the method from the class in order to populate the combo box with the selcted information
/// To display one or more Items.
/// </summary>
private void populateProductCombo()
{
cboProducts.DataSource = _order.getProducts();
cboProducts.DataTextField = "ProdustsName";
cboProducts.DataValueField = "ProductsID";
cboProducts.SelectedIndex = -1;//will make the combo box select nothing
cboProducts.DataBind();
}
/// <summary>
/// Pre-Condition: Event method call
/// Post-Condition: Empties fields
/// Description: Method used to empty all the fields
/// </summary>
private void emptyTopControls()
{
cboSalesAgent.SelectedIndex = -1;
cboRetailer.SelectedIndex = -1;
txtRetailerAddress.Text = "";
txtRetailerPhone.Text = "";
}
//mutators
/// <summary>
/// Pre-Condition: Event call Method
/// Post-Condition: Empties the controls for the lower section
/// Description: This will empty the controls of the lower section so the user can in put another item
/// In side the DataTable of the gridView we are casting the datasource as a data table in order
/// for us to delete the information inside each of the rows of the data table.
/// </summary>
private void emptyControls()
{
cboProducts.SelectedIndex = -1;
txtPrice.Text = "";
txtQty.Text = "";
txtSubTotal.Text = string.Empty;
btnInsert.Enabled = true;
btnUpdate.Enabled = false;
dgvOrderLine.DataSource = _order.getOrderLinesTable();
}
/// <summary>
/// Pre-Condtion: Event Call
/// Post-Condition: Send information to the list grid
/// Description: This method will send the infromation from the selection side into the display list
/// </summary>
private void assignChildData()
{
_order.OrderLineClass.ProductsID = long.Parse(cboProducts.SelectedValue.ToString());
_order.OrderLineClass.Qty = long.Parse(txtQty.Text);
_order.OrderLineClass.Price = decimal.Parse(txtPrice.Text.Substring
(txtPrice.Text.IndexOf('$') + 1));
_order.OrderLineClass.SalesOrderID = _order.PKID;
_order.OrderLineClass.LineTotal = decimal.Parse(txtSubTotal.Text);
_order.OrderLineClass.ProdustsName = cboProducts.Text;
}
/// <summary>
/// Pre-Condition: Event Call
/// Post-Condition: Assings informatin to the text/combo fields
/// Description: This is called when ever the fields have information that needs displayed
/// </summary>
private void assignData()
{
DateTime date = Convert.ToDateTime(dtpSalesOrder.Text);
_order.RetailerID = long.Parse(cboRetailer.SelectedValue.ToString());
_order.SalesDate = date;
_order.EmployeeID = long.Parse(cboSalesAgent.SelectedValue.ToString());
_order.RetailerAddress = txtRetailerAddress.Text;
_order.RetailerPhone = txtRetailerPhone.Text;
_order.SaleTotal = decimal.Parse(lblTotal.Text.Substring
(lblTotal.Text.IndexOf('$') + 1));
}
#endregion
protected void cboRetailer_SelectedIndexChanged(object sender, EventArgs e)
{
DataRowView drvCost = (DataRowView)cboRetailer.SelectedValue;
txtRetailerAddress.Text = drvCost["RetailerAddress"].ToString();
txtRetailerPhone.Text = drvCost["RetailerPhone"].ToString();
}
}
答案 0 :(得分：1)
cboRetailer.SelectedValue是一个字符串，您无法将其转换为DataRowView。
您可以尝试这样的事情：
修改
如果getCustomers（）返回一个数据表，你可以这样做：
protected void cboRetailer_SelectedIndexChanged(object sender, EventArgs e)
{
var dt = _order.getCustomers();
for (int i = 0; i < dt.Rows.Count; i++)
{
if (dt.Rows[i]["RetailerID"].ToString() == cboRetailer.SelectedValue)
{
txtRetailerAddress.Text = dt.Rows[i]["RetailerAddress"].ToString();
txtRetailerPhone.Text = dt.Rows[i]["RetailerPhone"].ToString();
}
}
}
或者如果getCustomers（）返回IEmunerable<Customer>，您可以这样做：
protected void cboRetailer_SelectedIndexChanged(object sender, EventArgs e)
{
int retailerID = 0;
if(int.TryParse(cboRetailer.SelectedValue, out retailerID) && retailerID > 0)
{
var retailer = _order.getCustomers().Where(x => x.RetailerID == retailerID).FirstOrDefault();
if (retailer != null)
{
txtRetailerAddress.Text = retailer.RetailerAddress;
txtRetailerPhone.Text = retailer.RetailerPhone;
}
}
}