我在下面有这个代码。我正在尝试按需在gridview中添加行，然后在gridview中绑定下拉列表，并在添加新行时想要保留在上一行中选择的值。问题是我能够绑定下拉列表并进行级联，但是在添加新行时，我无法保留前一行的选择。请查看代码并告诉我错误的地方。
<asp:GridView ID="gvAdvisor" runat="server" ShowFooter="true" AutoGenerateColumns="false" Width="895px" OnRowDataBound="gvAdvisor_RowDataBound">
<Columns>
<asp:BoundField DataField="RowNumber" HeaderText="Row Number" />
<asp:TemplateField HeaderText="Region">
<ItemTemplate>
<asp:DropDownList ID="ddRegion" runat="server" AutoPostBack="True" OnSelectedIndexChanged="ddRegion_SelectedIndexChanged">
</asp:DropDownList>
</ItemTemplate>
</asp:TemplateField>
<asp:TemplateField HeaderText="Agency">
<ItemTemplate>
<asp:DropDownList ID="ddAgency" runat="server" AutoPostBack="True" OnSelectedIndexChanged="ddAgency_SelectedIndexChanged">
</asp:DropDownList>
</ItemTemplate>
</asp:TemplateField>
<asp:TemplateField HeaderText="Firm">
<ItemTemplate>
<asp:DropDownList ID="ddFirm" runat="server" AutoPostBack="True" OnSelectedIndexChanged="ddFirm_SelectedIndexChanged">
</asp:DropDownList>
</ItemTemplate>
</asp:TemplateField>
<asp:TemplateField HeaderText="Office">
<ItemTemplate>
<asp:DropDownList ID="ddOffice" runat="server" AutoPostBack="True" OnSelectedIndexChanged="ddOffice_SelectedIndexChanged">
</asp:DropDownList>
</ItemTemplate>
</asp:TemplateField>
<asp:TemplateField HeaderText="Advisor">
<ItemTemplate>
<asp:DropDownList ID="ddAdvisor" runat="server">
</asp:DropDownList>
</ItemTemplate>
</asp:TemplateField>
<asp:TemplateField HeaderText="%">
<ItemTemplate>
<asp:TextBox ID="txtPercent" runat="server" />
</ItemTemplate>
<FooterStyle HorizontalAlign="Right" />
<FooterTemplate>
<asp:Button ID="AddRowButton" runat="server" Text="Add New Row"
OnClick="ButtonAdd_Click" />
</FooterTemplate>
</asp:TemplateField>
</Columns>
</asp:GridView>
protected void Page_Load(object sender, EventArgs e)
{
if (!IsPostBack)
{
SetInitialRow();
}
}
private void SetInitialRow()
{
try
{
DataTable dt = new DataTable();
DataRow dr = null;
dt.Columns.Add(new DataColumn("RowNumber", typeof(string)));
dt.Columns.Add(new DataColumn("Column1", typeof(string)));
dt.Columns.Add(new DataColumn("Column2", typeof(string)));
dt.Columns.Add(new DataColumn("Column3", typeof(string)));
dt.Columns.Add(new DataColumn("Column4", typeof(string)));
dt.Columns.Add(new DataColumn("Column5", typeof(string)));
dt.Columns.Add(new DataColumn("Column6", typeof(string)));
dr = dt.NewRow();
dr["RowNumber"] = 1;
dr["Column1"] = string.Empty;
dr["Column2"] = string.Empty;
dr["Column3"] = string.Empty;
dr["Column4"] = string.Empty;
dr["Column5"] = string.Empty;
dr["Column6"] = string.Empty;
dt.Rows.Add(dr);
//Store the DataTable in ViewState
ViewState["CurrentTable"] = dt;
gvAdvisor.DataSource = dt;
gvAdvisor.DataBind();
}
catch (Exception Ex)
{
//logger.Info("SetInitialRow : " + Ex.Message);
}
}
private void AddNewRowToGrid()
{
try
{
int rowIndex = 0;
if (ViewState["CurrentTable"] != null)
{
DataTable dtCurrentTable = (DataTable)ViewState["CurrentTable"];
DataRow drCurrentRow = null;
if (dtCurrentTable.Rows.Count > 0)
{
//extract the TextBox values
//if (tbBushels.Text != "" && tbLocation.Text != "" && tbFuture.Text != "" && tbBasis.Text != "" && tbPrice.Text != "" && tbRevenue.Text != "")
//{
for (int i = 1; i <= dtCurrentTable.Rows.Count; i++)
{
DropDownList Region =
(DropDownList)gvAdvisor.Rows[rowIndex].Cells[1].FindControl("ddRegion");
DropDownList Agency =
(DropDownList)gvAdvisor.Rows[rowIndex].Cells[2].FindControl("ddAgency");
DropDownList Firm =
(DropDownList)gvAdvisor.Rows[rowIndex].Cells[3].FindControl("ddFirm");
DropDownList Office =
(DropDownList)gvAdvisor.Rows[rowIndex].Cells[4].FindControl("ddOffice");
DropDownList Advisor =
(DropDownList)gvAdvisor.Rows[rowIndex].Cells[5].FindControl("ddAdvisor");
TextBox Percent =
(TextBox)gvAdvisor.Rows[rowIndex].Cells[6].FindControl("txtPercent");
drCurrentRow = dtCurrentTable.NewRow();
drCurrentRow["RowNumber"] = i + 1;
drCurrentRow["Column1"] = Region.SelectedItem.Value;
drCurrentRow["Column2"] = Agency.SelectedItem.Value;
drCurrentRow["Column3"] = Firm.SelectedItem.Value;
drCurrentRow["Column4"] = Office.SelectedItem.Value;
drCurrentRow["Column5"] = Advisor.SelectedItem.Value;
drCurrentRow["Column6"] = Percent.Text;
rowIndex++;
}
//add new row to DataTable
dtCurrentTable.Rows.Add(drCurrentRow);
//Store the current data to ViewState
ViewState["CurrentTable"] = dtCurrentTable;
//Rebind the Grid with the current data
gvAdvisor.DataSource = dtCurrentTable;
gvAdvisor.DataBind();
//}
}
}
else
{
Response.Write("ViewState is null");
}
//Set Previous Data on Postbacks
SetPreviousData();
}
catch (Exception Ex)
{
//logger.Info("AddNewRowToGrid : " + Ex.Message);
}
}
private void SetPreviousData()
{
try
{
int rowIndex = 0;
if (ViewState["CurrentTable"] != null)
{
DataTable dt = (DataTable)ViewState["CurrentTable"];
if (dt.Rows.Count > 0)
{
for (int i = 1; i < dt.Rows.Count; i++)
{
DropDownList Region =
(DropDownList)gvAdvisor.Rows[rowIndex].Cells[1].FindControl("ddRegion");
Region.SelectedItem.Value = dt.Rows[i]["Column1"].ToString();
foreach (GridViewRow gvr in gvAdvisor.Rows)
{
if (gvr.RowType == DataControlRowType.DataRow)
{
// DropDownList ddRegion = (DropDownList)gvr.FindControl("ddRegion");
DropDownList ddAgency = (DropDownList)gvr.FindControl("ddAgency");
if (Region.SelectedItem.Value == "0")
{
}
else
{
ddHelp.BindAgencyByRegion(ddAgency, Convert.ToInt32(Region.SelectedItem.Value));
}
ListItem ll1 = new ListItem("Select", "0");
ddAgency.Items.Insert(0, ll1);
}
}
DropDownList Agency =
(DropDownList)gvAdvisor.Rows[rowIndex].Cells[2].FindControl("ddAgency");
Agency.SelectedItem.Value = dt.Rows[i]["Column2"].ToString();
foreach (GridViewRow gvr in gvAdvisor.Rows)
{
if (gvr.RowType == DataControlRowType.DataRow)
{
//DropDownList ddAgency = (DropDownList)gvr.FindControl("ddAgency");
DropDownList ddFirm = (DropDownList)gvr.FindControl("ddFirm");
if (Agency.SelectedItem.Value == "0")
{
}
else
{
ddHelp.BindFirm(ddFirm, Convert.ToInt32(Agency.SelectedItem.Value));
}
ListItem ll2 = new ListItem("Select", "0");
ddFirm.Items.Insert(0, ll2);
}
}
DropDownList Firm =
(DropDownList)gvAdvisor.Rows[rowIndex].Cells[3].FindControl("ddFirm");
Firm.SelectedItem.Value = dt.Rows[i]["Column3"].ToString();
foreach (GridViewRow gvr in gvAdvisor.Rows)
{
if (gvr.RowType == DataControlRowType.DataRow)
{
//DropDownList ddFirm = (DropDownList)gvr.FindControl("ddFirm");
DropDownList ddOffice = (DropDownList)gvr.FindControl("ddOffice");
if (Firm.SelectedItem.Value == "0")
{
}
else
{
ddHelp.BindOffice(ddOffice, 0, Convert.ToInt32(Firm.SelectedItem.Value), 0);
}
ListItem ll3 = new ListItem("Select", "0");
ddOffice.Items.Insert(0, ll3);
}
}
DropDownList Office =
(DropDownList)gvAdvisor.Rows[rowIndex].Cells[4].FindControl("ddOffice");
Office.SelectedItem.Value = dt.Rows[i]["Column4"].ToString();
foreach (GridViewRow gvr in gvAdvisor.Rows)
{
if (gvr.RowType == DataControlRowType.DataRow)
{
//DropDownList ddOffice = (DropDownList)gvr.FindControl("ddOffice");
DropDownList ddAdvisor = (DropDownList)gvr.FindControl("ddAdvisor");
if (Office.SelectedItem.Value == "0")
{
}
else
{
ddHelp.BindAdvisor(ddAdvisor, 0, 0, Convert.ToInt32(Office.SelectedItem.Value));
}
ListItem ll4 = new ListItem("Select", "0");
ddAdvisor.Items.Insert(0, ll4);
}
}
DropDownList Advisor =
(DropDownList)gvAdvisor.Rows[rowIndex].Cells[5].FindControl("ddAdvisor");
TextBox Percent =
(TextBox)gvAdvisor.Rows[rowIndex].Cells[6].FindControl("txtPercent");
Advisor.SelectedItem.Value = dt.Rows[i]["Column5"].ToString();
Percent.Text = dt.Rows[i]["Column6"].ToString();
rowIndex++;
}
}
}
}
catch (Exception Ex)
{
//logger.Info("SetPreviousData : " + Ex.Message);
}
}
protected void ButtonAdd_Click(object sender, EventArgs e)
{
AddNewRowToGrid();
}
答案 0 :(得分：0)
在gvAdvisor_RowDataBound event
示例：(Dropdownlist)(gvAdvisor.Rows[i].findcontrol("ddRegion")).SelectedValue = datatable[i]["Region"];
您需要调整上述代码以最适合您的网格视图
您也可以对其他控件使用类似的逻辑Checkbox，radiobuttons等
答案 1 :(得分：0)
protected void gvAdvisor_RowDataBound(object sender, GridViewRowEventArgs e)
{
if (ViewState["CurrentTable"] != null)
{
Datatable dt = (Datatable)ViewState["CurrentTable"];
if (e.Row.RowType == DataControlRowType.DataRow)
{
((DropDownList)gvAdvisor.Rows[rowIndex].FindControl("ddRegion")).SelectedValue = dt[rowindex]["Column1"];
((DropDownList)gvAdvisor.Rows[rowIndex].FindControl("ddRegion")).Items.Insert(0,new ListItem("Select", "0"));
}
}
else
{
SetInitialRow();
}
}