Add New Blank Row Into Existing DataTable While Looping Problem.

[Kelvin]

Hi All,

I wrote a program insert new row between rows while the datatable is
looping. It display the error message.
Exception Details: System.Argument Exception: This row already belongs
to this table.
[ArgumentExcepti on: This row already belongs to this table.]
System.Data.Dat aTable.InsertRo w(DataRow row, Int32 proposedID,
Int32 pos) +319
System.Data.Dat aRowCollection. Add(DataRow row) +14
ASP.Outstandrpt _aspx.CheckOrde r(Object src, EventArgs e) in
c:\Inetpub\wwwr oot\Outstandrpt .aspx:398
ASP.Outstandrpt _aspx.DetailGri d_setPage(Objec t src,
DataGridPageCha ngedEventArgs e) in
c:\Inetpub\wwwr oot\Outstandrpt .aspx:118
System.Web.UI.W ebControls.Data Grid.OnPageInde xChanged(DataGr idPageChangedEv entArgs
e) +111
System.Web.UI.W ebControls.Data Grid.OnBubbleEv ent(Object source,
EventArgs e) +395
System.Web.UI.C ontrol.RaiseBub bleEvent(Object source, EventArgs
args) +31
System.Web.UI.W ebControls.Data GridItem.OnBubb leEvent(Object source,
EventArgs e) +120
System.Web.UI.C ontrol.RaiseBub bleEvent(Object source, EventArgs
args) +31
System.Web.UI.W ebControls.Link Button.OnComman d(CommandEventA rgs e)
+122
System.Web.UI.W ebControls.Link Button.RaisePos tBackEvent(Stri ng
eventArgument) +288
System.Web.UI.W ebControls.Link Button.System.W eb.UI.IPostBack EventHandler.Ra isePostBackEven t(String
eventArgument) +5
System.Web.UI.P age.RaisePostBa ckEvent(IPostBa ckEventHandler
sourceControl, String eventArgument) +11
System.Web.UI.P age.RaisePostBa ckEvent(NameVal ueCollection postData)
+166
System.Web.UI.P age.ProcessRequ estMain(Boolean
includeStagesBe foreAsyncPoint, Boolean includeStagesAf terAsyncPoint)
+5157

my code:

y = myTable.Rows.Co unt;

DataRow dr = myTable.NewRow( );
DataRow mydr = myTable.NewRow( );

for (i=0; y > i ; i++ )
{
DataRow dataRow = myTable.Rows[i];
// DataRow dataRow = myTable.NewRow( );
if (myOrderNo == "")
{
myOrderNo = Convert.ToStrin g(dataRow["OrderNo"]);
}
else
{
if (y == i+1)
{
dataRow["CustNo"] = "Sub Total :";
dataRow["HDelivSeq"] = "";
myTable.Rows.Ad d(dataRow);
}
}

if (myOrderNo != Convert.ToStrin g(dataRow["OrderNo"]))
{
dataRow["CustNo"] = "Sub Total :";
dataRow["HDelivSeq"] = "";
dataRow["OrderNo"] = "";
myTable.Rows.Ad d(dataRow);
}
}
DetailGrid.Data Source = myTable;

[Lowell Heddings]

Here's the problem: You are creating the dataRow object and setting it
equal to a row that already exists right here:

DataRow dataRow = myTable.Rows[i];
And then you are attempting to add the row that already exists here:
myTable.Rows.Ad d(dataRow);
What you should be doing is using one of these variables that you've
created but not used:
DataRow dr = myTable.NewRow( );
DataRow mydr = myTable.NewRow( );

So in your loop, you need to do this:

DataRow dr = myTable.NewRow( );
// do any processing here to the datarow
myTable.Rows.Ad d(dr);

The whole point of using NewRow() is to create a new row object that has
the same schema as the table. But you have to add that same object to
the table.

Lowell