A problem with the datagrid

  • Thread starter Thread starter Pearl.Elevation
  • Start date Start date
P

Pearl.Elevation

Hi, I am just beginning to learn to use the .Net framework and recently
I confront a problem with the datagrid.

I create an .asp file. There are two buttons, one datagrid on the
screen.
The first button is "Show" button. When I click this button, it will
call the data in the sql Server and bind the data to the datagrid. The
code is:

ArrayList alErrorIn = new ArrayList();
DataTable dtBookAdmin =
objBOBookAminManipulation.GetBookAdminsInterface(out alErrorIn);
dgBookAdmin.DataSource = dtBookAdmin;
dgBookAdmin.DataBind();

It works fine.
The second button is "Delete" button. There is a template colum in the
datagrid. When I choose the item and click the "Delete" button, the
corresponding items in the datagrid will be deleted. But it won't work
fine. When I debug, I check the datagrid before I do the delete:
private void btnDelete_Click(object sender, System.EventArgs e)
{
int iCount = dgBookAdmin.Items.Count;
ArrayList alDeleteid = new ArrayList();
foreach(DataGridItem dataGridItem in dgBookAdmin.Items)
....

But the iCount show that there is no item in the datagrid. But there
are items showed in the screen and I check the value after I have bind
the data to the datagrid, it's fine.
So I get confused. Could anyone clear my problem? Thank you very much!
 
Did you count the number of items in dbBookAdmin.DataSource ?
What you want might be something like
((DataTable)dbBookAdmin.DataSource).Clear() in order to remove all the
items of the DataTable.
 
Do you need to check the datagrid?

In your template column you have the code for the asp.net button
control, why don't you add the row's unique id to the CommandArgument
property of the delete button.

Then use the Datagrids ItemCommand method which is fired whenever an
item in the datagrid triggers a command, which the delete button will
do.

The code for the Item command is as follows:

private void DataGrid1_ItemCommand(object source,
DataGridCommandEventArgs e)
{
if (e.CommandName == "Delete")
{
DeleteThisRecord(int.Parse(e.CommandArgument));
}
}

The code for the Button within the template control is as follows:

<asp:button Runat=server ID="btnDelete" CommandArgument='<%#
Databinder.Eval(Container.DataItem, "ID") %>'
CommandName="Delete"></asp:button>

I may have the syntax for the databinding statement wrong but you can
look that up.

By doing it this way it allows you to pass through the ID of the row
you wish to delete, thus you don't need to check any records. You
simply send the delete command to the database, and then re-databind
your datagrid.

Hope this helps

Pete
 
Thank you for your suggestion. But, it is not working.
When I came to the Itemcommand function, any event I do on the datagrid
is not work. So I check if the data is still there in the datagrid, and
find that all the data I binded successful to the datagrid is lost.
That's why I check the numbers of the rows in the datagrid. And the
number is 0. And I don't know why is that.
 
Is the event being triggered?

If you are writing your code in C# please check the event handlers in
the Windows Generated code section.

Also could you post the code so that I can help you better?

Many thanks

Pete
 
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