private void ActPrimaryKey_Click(System.Object sender, System.EventArgs e)
{
// ----- Perform a primary key lookup.
long usePrimaryKey;
DataRow result = null;
DataTable workTable;
DataTable displayTable;
// ----- The primary key is required, and must be an integral value.
if ((IsNumeric(PrimaryKey.Text.Trim()) == false) ||
(PrimaryKey.Text.IndexOf(".") >= 0))
{
MessageBox.Show("The Primary Key must be a valid integer.");
PrimaryKey.Focus();
return;
}
// ----- Convert supplied key to long, checking for overflow.
try
{
usePrimaryKey = long.Parse(PrimaryKey.Text);
}
catch
{
MessageBox.Show("The Primary Key must be a valid integer.");
PrimaryKey.Focus();
return;
}
// ----- Get a copy of the table for the lookup.
workTable = BuildSampleTable();
// ----- Perform the lookup.
try
{
result = workTable.Rows.Find(usePrimaryKey);
}
catch (MissingPrimaryKeyException)
{
MessageBox.Show("The table does not have a defined primary key.");
return;
}
catch (Exception ex)
{
MessageBox.Show("Primary key lookup failed with the following error: " +
ex.Message);
return;
}
// ----- Check for no match.
if (result == null)
{
MessageBox.Show("The supplied key matched no rows.");
PrimaryKey.Focus();
return;
}
// ----- Display the results. The results panel requires a DataTable,
// so build a new table that includes only the matching row.
displayTable = workTable.Clone();
displayTable.ImportRow(result);
(new ResultsViewer()).ShowResults(displayTable);
}
