RegisterArrayDeclaration Help Needed with Grid

[xenophon]

I have a grid with checkboxes in it. When a checkbox is un/checked, I
want to set a true-false value in an array. Then on PostBack I can
work with that array.

I know I need to use RegisterArrayDe claration, but I don't see a quick
tutorial how. Can anyone post sample C# code-behind-only code on how
to do this?

Thanks.

[Scott Allen]

Re: RegisterArrayDe claration Help Needed with Grid

Just as an alternate solution: you could loop through the grid on
postback and pick out which rows have the checkbox checked.

there is some sample code in this article:

http://odetocode.com/Articles/372.aspx

--
Scott

http://www.OdeToCode.com/blogs/scott/

On Tue, 17 May 2005 21:44:25 -0400, xenophon <xenophon@onlin e.nospam>
wrote:
[color=blue]
>
>I have a grid with checkboxes in it. When a checkbox is un/checked, I
>want to set a true-false value in an array. Then on PostBack I can
>work with that array.
>
>I know I need to use RegisterArrayDe claration, but I don't see a quick
>tutorial how. Can anyone post sample C# code-behind-only code on how
>to do this?
>
>Thanks.
>[/color]

[Steven Cheng[MSFT]]

Re: RegisterArrayDe claration Help Needed with Grid

Thanks for Scott's informative suggestion.

Hi Xenophon ,

As Scott has mentioned, we can query the select status in each datagrid Row
at serverside when post back rather than use clientsdie script to store
these info. Since the serverside ASP.NET provide a convenient object model
for us to access the datagrid's item template, I think it'll be much
better. What's your oponion on this?

Thanks,

Steven Cheng
Microsoft Online Support

Get Secure! www.microsoft.com/security
(This posting is provided "AS IS", with no warranties, and confers no
rights.)

[xenophon]

Re: RegisterArrayDe claration Help Needed with Grid

Thanks, but I won't be able to do that because I am not keeping the
ViewState contents because the grid is complex and large. Pushing a
couple of hundred kbytes back upstream just to know a checkbox state
is too much for this app.



On Tue, 17 May 2005 22:47:59 -0400, Scott Allen
<scott@nospam.o detocode.com> wrote:
[color=blue]
>Just as an alternate solution: you could loop through the grid on
>postback and pick out which rows have the checkbox checked.
>
>there is some sample code in this article:
>http://odetocode.com/Articles/372.aspx[/color]

[xenophon]

Re: RegisterArrayDe claration Help Needed with Grid




I cannot use this solution. The rendered grid is very large and
complex, so EnableViewState is set to false for the grid. I just need
to know the state of the checkboxes, with just the checkbox state (and
grid row id) going back upstream.

Please show an example of how I can do this, using only C# (my grids
are not created in the .aspx page tempalte at all).

Thanks.




On Wed, 18 May 2005 08:20:54 GMT, v-schang@online.m icrosoft.com
(Steven Cheng[MSFT]) wrote:
[color=blue]
>Thanks for Scott's informative suggestion.
>
>Hi Xenophon ,
>
>As Scott has mentioned, we can query the select status in each datagrid Row
>at serverside when post back rather than use clientsdie script to store
>these info. Since the serverside ASP.NET provide a convenient object model
>for us to access the datagrid's item template, I think it'll be much
>better. What's your oponion on this?
>
>Thanks,
>
>Steven Cheng
>Microsoft Online Support
>
>Get Secure! www.microsoft.com/security
>(This posting is provided "AS IS", with no warranties, and confers no
>rights.)[/color]

[Steven Cheng[MSFT]]

Re: RegisterArrayDe claration Help Needed with Grid

Hi Xenophon,

Thanks for your followup.
If what you worried about is the DataGrid being disabled for Viewstate,
then that's doesn't matter since we can still retrieve the controls from
DataGrid.Items collection when posting back as long as we bind data with
datagrid everytime in the Page_Load. Anyway, I've made a simple demo page
which have used both the two means :
1. Use serverside datagrid obejct model to query the checkbox controls and
get the checked state.

2. Use clientside script to save all the checkboxes's checked states before
post back to server.

The page's code are pasted in the bottom of the message, you can have a
test on your side to see whether it helps.

Thanks,

Steven Cheng
Microsoft Online Support

Get Secure! www.microsoft.com/security
(This posting is provided "AS IS", with no warranties, and confers no
rights.)

=============== aspx=========== =========
<HTML>
<HEAD>
<title>checkbox grid</title>
<meta name="GENERATOR " Content="Micros oft Visual Studio .NET 7.1">
<meta name="CODE_LANG UAGE" Content="C#">
<meta name="vs_defaul tClientScript" content="JavaSc ript">
<meta name="vs_target Schema"
content="http://schemas.microso ft.com/intellisense/ie5">
<script language="jscri pt">
function saveCheckArray( )
{
var i=0;
var array = new Array();
for(i=0;i<docum ent.all.length; i++)
{
if(document.all[i].type == "checkbox" &&
document.all[i].id.indexOf("dg Check")> -1)
{
var chk = document.all[i];
array.push(chk. checked);

}

}

document.getEle mentById("check Array").value = array.join("|") ;
}
</script>
</HEAD>
<body>
<form id="Form1" method="post" runat="server">
<asp:DataGrid id="dgCheck" runat="server" AutoGenerateCol umns="False"
EnableViewState ="False">
<Columns>
<asp:BoundColum n HeaderText="Nam e" DataField="name "></asp:BoundColumn >
<asp:TemplateCo lumn HeaderText="Sel ected">
<ItemTemplate >
<asp:CheckBox ID="chkSelect" Runat="server" Checked="<%#
((System.Data.D ataRowView)Cont ainer.DataItem)[1] %>">
</asp:CheckBox>
</ItemTemplate>
</asp:TemplateCol umn>
</Columns>
</asp:DataGrid>
<input type="hidden" id="checkArray " runat="server">

<P>
<asp:Button id="btnSubmit" runat="server" Text="Submit"></asp:Button>
</P>
</form>
</body>
</HTML>

=========code behind========= ============
public class checkboxgrid : System.Web.UI.P age
{
protected System.Web.UI.W ebControls.Butt on btnSubmit;
protected System.Web.UI.H tmlControls.Htm lInputHidden checkArray;

protected System.Web.UI.W ebControls.Data Grid dgCheck;

private void Page_Load(objec t sender, System.EventArg s e)
{
dgCheck.DataSou rce = GetDataSource() ;
dgCheck.DataBin d();

btnSubmit.Attri butes["onclick"] ="saveCheckArra y();";
}

private DataTable GetDataSource()
{
DataTable dt = new DataTable();

dt.Columns.Add( "name",typeof(s tring));
dt.Columns.Add( "selected",type of(bool));

for(int i=0;i<10;i++)
{
DataRow dr = dt.NewRow();
dr[0] = "Name_" + i;
dr[1] = i%3 == 0? true:false;

dt.Rows.Add(dr) ;
}

return dt;

}


#region Web Form Designer generated code
override protected void OnInit(EventArg s e)
{
InitializeCompo nent();
base.OnInit(e);
}

private void InitializeCompo nent()
{
this.btnSubmit. Click += new System.EventHan dler(this.btnSu bmit_Click);
this.Load += new System.EventHan dler(this.Page_ Load);

}
#endregion

private void btnSubmit_Click (object sender, System.EventArg s e)
{
CheckBox chk = null;
int i = 0;


Response.Write( "<br>Values from DataGrid server object:");
for(i=0;i<dgChe ck.Items.Count; i++)
{
chk = dgCheck.Items[i].FindControl("c hkSelect") as CheckBox;

Response.Write( string.Format(" <br/>Item {0} Selected: {1}", i,
chk.Checked));
}

Response.Write( "<br>Values from clientside input hidden field:");

string[] items = checkArray.Valu e.Split("|"[0]);

for(i=0;i<items .Length;i++)
{
Response.Write( string.Format(" <br/>Item {0} Selected: {1}", i,
items[i]));
}
}
}
=============== =======

[Steven Cheng[MSFT]]

Re: RegisterArrayDe claration Help Needed with Grid

Hi Xenophon,

Any progress on this issue? Does the test page I pasted in the former
message help? If anything else we can help, please feel free to post here.

Thanks & Regards,

Steven Cheng
Microsoft Online Support

Get Secure! www.microsoft.com/security
(This posting is provided "AS IS", with no warranties, and confers no
rights.)