[Mono-dev] Adding data to a dataset question

[Morten Mertner]

Hi Paul,

you are modifying the existing datarow reference, and instead need to 
create a new DataRow instance.

Yours,
Morten


Paul F. Johnson wrote:

>Hi,
>
>I'm trying to add multiple lines to a dataset but keep hitting the same
>problem. Now, I can get around the problem, but I'm not happy with how I have
>to do it.
>
>The code looks like this
>
>		private void FillDataSet()
>		{
>			// create a new DataTable in the DataSet
>			dsSource.Tables.Add("sites");
>			dsSource.Tables["sites"].Columns.Add("url", Type.GetType("System.String"));
>			dsSource.Tables["sites"].Columns.Add("name",
>Type.GetType("System.String"));
>			
>			// create a few rows and add them to the DataTable
>			DataRow tempRow = dsSource.Tables["sites"].NewRow();
>			tempRow["url"] = "http://www.gotmono.com";
>			tempRow["name"] = "Mono community page";
>			dsSource.Tables["sites"].Rows.Add(tempRow);
>			
>			tempRow["url"] = "http://www.go-mono.com/tutorial";
>			tempRow["name"] = "The Mono handbook";
>			dsSource.Tables["sites"].Rows.Add(tempRow);
>			
>			tempRow["url"] = "http://www.go-mono.com";
>			tempRow["name"] = "The main Mono website";
>			dsSource.Tables["sites"].Rows.Add(tempRow);
>			
>		        tempRow["url"] =
>"http://www.nullenvoid.com/mono/wiki/index.php/WineSamples";
>			tempRow["name"] = "Mono WineSamples";
>			dsSource.Tables["sites"].Rows.Add(tempRow);
>		}
>		
>		private void BindControls()
>		{
>			// Bind the listBox
>			listBox1.DataSource = dsSource.Tables["sites"];
>			listBox1.DisplayMember = "name";
>			listBox1.ValueMember = "url";
>			
>			// Bind the combobox
>			comboBox1.DataSource = dsSource.Tables["sites"];
>			comboBox1.DisplayMember = "name";
>			comboBox1.ValueMember = "url";
>			
>			// Bind the DataGrid to the DataSet
>			dataGrid.DataSource = dsSource;
>			
>			// Bind the second DataGrid to the DataSet
>			dataGrid2.DataSource = dsSource.Tables["sites"];
>			
>			// Bind the Textboxes to the selected row
>			textBox.DataBindings.Add("text", dsSource.Tables["sites"], "name");
>			textBox2.DataBindings.Add("text", dsSource.Tables["sites"], "url");
>		}
>
>Clearly, the problem is coming from using temp constantly in the setting of
>the data (if I comment out all but the first dataadd set, the program works
>correctly-ish). The solution looks to be use an array of temps to add the
>data.
>
>If the dataset type was an int, I could say ds.AutoIncrement (according to
>MSDN).
>
>Is there a way to reuse temp or is the problem in that when the data is added,
>the row counter is not incremented and so I'm trying to overwrite the same
>data time and again?
>
>TTFN
>
>Paul
>  
>