Gridview

nkvd3941 · October 22nd, 2009, 06:02 AM

Hi Imar / All

I am about 1/2 way thru your Begiining ASP.NET 3.5 in C# & VB - find it to be excellent.

Got to gridview chapter - question is:
How do i build a gridview without using the wizards? ie to have more control on what i am doing, build the gridview from scratch, add in the columns, bind to the db.
Is their coding examples around of doing this, or even another wrox book for sale showing me just this? I would buy another book for this info alone.

For example, how to add a checkbox into the gridview that isnt bound to the underlying db, and how to interrogate the contents of the checkbox - i had major problems trying to find the value of the checkbox.

Many thanks

Imar · October 22nd, 2009, 06:21 AM

Hi there,

You may find what you need here:

http://www.highoncoding.com/Categori...r_Control.aspx

Alternatively, post some more details and we may be able to help you out here.

Cheers,

Imar

nkvd3941 · October 22nd, 2009, 07:12 AM

Hi

Thanks for quick reply.
What i am trying to do:

a. I have a gridview thats bound to a table, with 4 columns.
b. I have added a fifth column, a checkbox, using Edit fields
c. I wish to then iterate thru the gridview's rows, picking out the selected rows, and process those, using the key of the row to whatever processing.
I cant seem to find a value for the checkbox

Many thanks

Imar · October 22nd, 2009, 07:43 AM

Hi there,

You need to use FindControl on the GridViewRow to find the check box. Something like this should work:

Code:

 <asp:GridView ID="GridView1" runat="server" AutoGenerateColumns="False" DataKeyNames="Id" 
    DataSourceID="SqlDataSource1">
  <Columns>
    <asp:BoundField DataField="Id" HeaderText="Id" InsertVisible="False" ReadOnly="True" 
           SortExpression="Id" />
  <asp:BoundField DataField="Description" HeaderText="Description" SortExpression="Description" />
    <asp:TemplateField>
      <ItemTemplate>
        <asp:CheckBox ID="CheckBox1" runat="server" />
      </ItemTemplate>
    </asp:TemplateField>
  </Columns>
</asp:GridView>
<asp:Button ID="Button1" runat="server" Text="Button" />

This GridView is using a SqlDataSource with a simple select like SELECT Id, Description FROM SomeTable. The Id is an integer.

Then in the Click event handler of the button you can check the CheckBox like this:

Code:

protected void CheckBox1_CheckedChanged(object sender, EventArgs e)
{
  foreach (GridViewRow item in GridView1.Rows)
  {
    if (item.RowType == DataControlRowType.DataRow)
    {
      CheckBox myCheckBox = item.FindControl("CheckBox1") as CheckBox;
      if (myCheckBox != null && myCheckBox.Checked)
      {
        int primaryKey = Convert.ToInt32(GridView1.DataKeys[item.DataItemIndex].Value);
        Label1.Text += String.Format("{0}<br />", primaryKey);
      }
    }
  }
}

Hope this helps,

Imar

nkvd3941 · October 22nd, 2009, 09:05 AM

Alleluia - many thanks

nkvd3941 · October 30th, 2009, 12:32 PM

Hi again

Does "Edit and Continue" work in Web programming in the same way as in Windows programming? Every time I make a change to the c# code in web and try to continue, i get "The source file hase changed..." message and have to recompile everyhing before continuing.

Imar · October 30th, 2009, 12:51 PM

Hi there,

It works in Web Application Projects, but AFAIK, it doesn't work in Web Site Projects....

For more info: http://whyiamright.wordpress.com/200...l-studio-2005/

Imar

nkvd3941 · October 31st, 2009, 10:33 AM

a. This may sound a bit dim but i cant find the web project property pages anywhere. I have seen the same screen u pointed to on numerous web sites now. I have VS 2008 SP2
b. Whats the best place to set Session variables? I keep losing values of atext box, even though i am setting the Session variable in the TextChanged event. Any tips?

Imar · October 31st, 2009, 10:41 AM

Quote:

I have VS 2008 SP2

That's odd. Service Pack 1 is the latest official release.... ;-)

Quote:

i cant find the web project property pages anywhere

Try this:

1. Start VS 2008
2. Choose File | New Web Site (not File | New project)
3. Right-click the site in the Solution Explorer (not the actual solution if you see it, but the web site beneath it) and choose Property Pages.

However, like I said, and like the aticle seems to confirm, Edit and Continue is not supported in Web Site Projects (File | New Web Site) but only in Web Application Projects (File | New Project)

Quote:

Whats the best place to set Session variables?

It depends on what you want to accomplish. Session variables should not affect the text of a TextBox unless you set the text explicitly. Showing some code might shed some light on this.

Cheers,

Imar

nkvd3941 · December 13th, 2009, 07:01 AM

Re: Chap 14, hooking into the RowDataBound event - i can successfully get values using the DataRowView; it it possible to *change* values in the cells. Also is it possible to change cell fonts / colors here?
Is this the right event to be doing this?