NOTE: I have slightly modified this post and the associated source. Make sure to take a look at v2 after reading this post:
http://blog.binaryocean.com/PermaLink,guid,a1ff6cab-dc2d-441c-8557-7dce920d4075.aspx
-Andrew
>>>
In ASP.NET version 1.x, I used the footer on the DataGrid control to insert new rows by placing a series of TextBox, DropDownLists, CheckBoxes etc. controls on it and then handling a save button. This also works with the GridView in version 2.0 but with one major exception: if your data source is empty, the GridView will hide your footer (and header) and only display the EmptyDataText.
Conventional wisdom says that you should use a DetailsView to insert rows, but I don't want to shift the user between two different controls. You can edit and delete rows with a GridView so why not Insert?
Here is the solution. I am using an ObjectDataSource control to wire up my data access class. If the DataTable coming back from my data class is empty, I add a null row. This works fine but now you get blank rows in the GridView. To handle that, I hide the rows during the RowCreated event. Lastly, I clear the controls off of the now hidden row so that there are no binding errors as would be the case with a cast boolean value which I do to set the value of a CheckBox in my GridView.
You can download the entire solution and sample database here:
http://download.binaryocean.com/GridViewInsertSolution.zip
private bool LoadDataEmpty
{
// some controls that are used within a GridView,
// such as the calendar control, can cuase post backs.
// we need to preserve LoadDataEmpty across post backs.
get { return (bool)(ViewState["LoadDataEmpty"] ?? false); }
set { ViewState["LoadDataEmpty"] = value; }
}
protected void ObjectDataSourceMain_Selected(object sender, ObjectDataSourceStatusEventArgs e)
{
// bubble exceptions before we touch e.ReturnValue
if (e.Exception != null)
{
throw e.Exception;
}
// get the DataTable from the ODS select mothod
DataTable dataTable = (DataTable)e.ReturnValue;
// if rows=0 then add a dummy (null) row and set the LoadDataEmpty flag.
if (dataTable.Rows.Count == 0)
{
dataTable.Rows.Add(dataTable.NewRow());
LoadDataEmpty = true;
}
else
{
LoadDataEmpty = false;
}
}
protected void GridViewMain_RowCreated(object sender, GridViewRowEventArgs e)
{
// when binding a row, look for a zero row condition based on the flag.
// if we have zero data rows (but a dummy row), hide the grid view row
// and clear the controls off of that row so they don't cause binding errors
if (LoadDataEmpty && e.Row.RowType == DataControlRowType.DataRow)
{
e.Row.Visible = false;
e.Row.Controls.Clear();
}
}
protected void GridViewMain_RowCommand(object sender, GridViewCommandEventArgs e)
{
// handle the save button on the footer row. this is the only manual data operation
// that must be done. update and delete are handled by the gridview and ODS
if (e.CommandName == "Save")
{
string code = ((TextBox)GridViewMain.FooterRow.FindControl("TextBoxCode")).Text;
string description = ((TextBox)GridViewMain.FooterRow.FindControl("TextBoxDescription")).Text;
bool isActive = ((CheckBox)GridViewMain.FooterRow.FindControl("CheckBoxIsActive")).Checked;
new LocationData().Insert(code, description, isActive);
GridViewMain.DataBind();
}
}