Modify Type of Dataset Column

C

catlook

New member
Joined
Jun 28, 2007
Messages
4
Im working with a windows foem application. I have a dataset that was returned from a webservice. The third column ("Permanent") contains a bool. When i bind the data to a datagridview, that coulmn shows up as a series of checked checkboxes (since all the rows happened to have "true" for that value). What I want to do is modify the dataset, before binding it to the grid, to display the word "Permanent" if the bool is true and "Temporary" is the bool is false. Ive gotten the code the point where I recognise whether its true or false, but, because the column expects a bool, I cant put in the appropriate string. Any suggestions?


Code: 
private void btnGetAccounts_Click(object sender, EventArgs e)
{
  BindingSource bs = new BindingSource();
  dsAccounts = new DataSet();
  dsAccounts = myAccount.List(nSessionID, out nError, out sErrorMsg);
  if (dsAccounts != null && dsAccounts.Tables.Count > 0)
  { 
    //modify datadisplay
    for (int i = 0; i < 10; i++)
    {
      if ((bool)dsAccounts.Tables[0].Rows[i][2] == true)
     {
       dsAccounts.Tables[0].Rows[i][2] = "Permanent";
     }
   }

  bs.DataSource = dsAccounts;
  bs.DataMember = dsAccounts.Tables[0].TableName; 
  dgvAccounts.DataSource = bs;
  }
}

The error I get is: "String was not recognised as valid Boolean. Couldnt store "Permanent" in Permanent column. Expected type is Boolean."

It has been suggested that I use the RowDataBound event, but, sa far as I know, that only applies to ASP. That event doesnt seem to be available for DataGridViews in windows forms applications.
 
Hi,

You cannot modify the column type once you have data in there.

Here is what I would do, its in vb as I am at work.
Code: 
 Dim dtResults As New DataTable

For Each dc As DataColumn In dtOriginalTable.Columns
    dtResults.Columns.Add(dc.ColumnName)
Next

For Each dc As DataColumn In dtResults.Columns
    If dc.ColumnName = "columnToChange" Then
        dc.DataType = System.Type.GetType("System.String")
    End If
Next

For Each drow As DataRow In dtOriginalTable.Rows
    dtResults.Rows.Add(drow.ItemArray)
    If Convert.ToBoolean(dtResults.Rows(dtResults.Rows.Count - 1).Item("columnToChange")) Then
        dtResults.Rows(dtResults.Rows.Count - 1).Item("columnToChange") = "Permanent"
    Else
        dtResults.Rows(dtResults.Rows.Count - 1).Item("columnToChange") = "Temporary"
    End If
Next

So you bind to the new datatable and it should fine.
 
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