RE: DataGrid Runtime DropDown - ViewState Issue
- From: "Elton W" <EltonW@xxxxxxxxxxxxxxxxxxxxxxxxx>
- Date: Sat, 11 Jun 2005 12:54:02 -0700
Hi Steve,
I think you might misunderstand something. In a datagrid, a datagrid item
becomes an so-called EditItem only when you assign it as EditItem, e.g. in
Edit event:
DataGrid.EditItemIndex = e.Item.ItemIndex
Datagrid.DataSource = data_source_object
Datagrid.DataBind()
Then the item, index as e.Item.ItemIndex becomes EditItem.
In ItemDataBound event, there are only two kinds of data-bound items,
ListItemType.Item and ListItemType.AlternatingItem.
HTH
Elton Wang
elton_wang@xxxxxxxxxxx
"Steve Pierce" wrote:
>
> I am having some issues with a runtime dropdownlist in a datagrid. The
> issue is that I cannot get ViewState to fill the selected index of a runtime
> dropdown properly on postback. I do not want to use template columns as they
> seem to be a little difficult to create at runtime. Any assistance would be
> very greatly appreciated.
>
> private void DataGrid1_ItemDataBound(object sender,
> System.Web.UI.WebControls.DataGridItemEventArgs e)
> {
> if (e.Item.ItemType == ListItemType.Item || e.Item.ItemType ==
> ListItemType.AlternatingItem)
> {
> // display all LooId values with related value in LookupValue for display
> foreach (LookupProperties lp in GetLookupCollection().Items)
> {
> // set the text of the cell based on the dataset
> DataRow dr = ((DataRowView)e.Item.DataItem).Row;
> int lovId = Convert.ToInt32(dr[lp.ColumnName]);
> e.Item.Cells[lp.ColumnIndex].Text = GetLookupValue(lovId);
> }
> }
> else if (e.Item.ItemType == ListItemType.EditItem)
> {
> // change all LooId columns from textbox to dropdownlist for edit
> foreach (LookupProperties lp in GetLookupCollection().Items)
> {
> // create and populate dropdownlist
> DataRow dr = ((DataRowView)e.Item.DataItem).Row;
> string controlName = "ddl_" + dr[dr.Table.PrimaryKey[0]] + "_" +
> lp.ColumnIndex;
> DropDownList ddl = new DropDownList();
> ddl.ID = controlName;
> ddl.CssClass = "DropDownList";
> ddl.EnableViewState = true;
> foreach (LookupValueRow lov in FrameworkDataSet.LookupValue)
> if (lov.LovLolId == lp.LolId && lov.LovId > 0)
> ddl.Items.Add(new ListItem(lov.LovDisplayValue, lov.LovId.ToString()));
> // select current value based on dataset
> ddl.SelectedValue = dr[lp.ColumnName].ToString();
> // replace default textbox control with new dropdownlist
> e.Item.Cells[lp.ColumnIndex].Controls.Clear();
> e.Item.Cells[lp.ColumnIndex].Controls.AddAt(0, ddl);
> ViewState[controlName] = e.Item.Cells[lp.ColumnIndex].Controls[0].UniqueID;
> }
> }
> }
> private void DataGrid1_ItemCommand(object source,
> System.Web.UI.WebControls.DataGridCommandEventArgs e)
> {
> if ((e.Item.ItemType == ListItemType.Header) ||
> (e.Item.ItemType == ListItemType.Footer) ||
> (e.Item.ItemType == ListItemType.Separator))
> return;
> if (e.CommandName != "Update")
> return;
> // update dataset for all LooId columns with dropdownlist selectedvalue
> foreach (LookupProperties lp in GetLookupCollection().Items)
> {
> // compare dropdownlist selectedvalue to dataset, update if changed
> int verId = Convert.ToInt32(DataGrid1.DataKeys[e.Item.ItemIndex]);
> DataRow dr = PageDataSet.Version.FindByVerId(verId);
> string controlName = "ddl_" + verId + "_" + lp.ColumnIndex;
> string uniqueName2 = ViewState[controlName].ToString();
> // error: selecteditems are not correct from viewstate
> DropDownList ddl = new DropDownList();
> ddl.ID = controlName;
> ddl.CssClass = "DropDownList";
> ddl.EnableViewState = true;
> foreach (LookupValueRow lov in FrameworkDataSet.LookupValue)
> if (lov.LovLolId == lp.LolId && lov.LovId > 0)
> ddl.Items.Add(new ListItem(lov.LovDisplayValue, lov.LovId.ToString()));
> e.Item.Cells[lp.ColumnIndex].Controls.Clear();
> e.Item.Cells[lp.ColumnIndex].Controls.AddAt(0, ddl);
> DropDownList ctl1 = (DropDownList)e.Item.Cells[lp.ColumnIndex].Controls[0];
> DropDownList ctl2 = (DropDownList)e.Item.FindControl(controlName);
> DropDownList ctl3 = (DropDownList)this.FindControl(uniqueName2);
> if (ddl.SelectedItem == null)
> {
> if (dr[lp.ColumnName].GetType() != typeof(DBNull))
> dr[lp.ColumnName] = DBNull.Value;
> else
> continue;
> }
> else
> {
> if (dr[lp.ColumnName].GetType() == typeof(DBNull))
> dr[lp.ColumnName] = ddl.SelectedValue;
> else if (dr[lp.ColumnName].ToString() != ddl.SelectedValue)
> dr[lp.ColumnName] = ddl.SelectedValue;
> else
> continue;
> }
> }
> }
>
> Steve Pierce
> Sterling Computer Consultants
> stevep@xxxxxxxxxxxxxx
>
>
>
.
- References:
- DataGrid Runtime DropDown - ViewState Issue
- From: Steve Pierce
- DataGrid Runtime DropDown - ViewState Issue
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