Unhandled Exception When Using DataRow foundRow With DataTable

Question

Again this is about a DataTable, not a database.

Few things:

• This is part of a WPF application
• The search happens as a result of a button event
• The DataTable is contained in its own class (MainDataTable.cs)
• The DataTable is populated by text input ('Page1.xaml.cs')
• The button and the search methods are contained in their own class(Page2.xaml.cs)
• I left out the XAML and how the Data is stored. If necessary, I can display it.

MainDataTable.cs (where the DataTable is contained)

public class MainDataTable
{
    public static DataTable dataMain = new DataTable("Customer Info Database");

    public static void CreateTable1()
    {
        dataMain.Columns.Add("CustID", typeof(int));
        dataMain.PrimaryKey = new DataColumn[] { dataMain.Columns["ID"] };
        dataMain.Columns.Add("CustName", typeof(string));
        dataMain.Columns.Add("CustAge", typeof(int));
        dataMain.Columns.Add("CustAlign", typeof(string));      
    }

    public static void EnterNewRows(int CustID, string CustName, int CustAge, string CustAlign)
    {
        dataMain.Rows.Add(CustID, CustName, CustAge, CustAlign);
    }
}

Page1.xaml.cs

public partial class Page1 : Page
{
    public Page1()
    {
        InitializeComponent();
    }

    private void Finished_Button(object sender, RoutedEventArgs e)
    {
        int ParseID;
        int ParseAge;
        bool Parse1 = int.TryParse(txtID.Text, out ParseID);
        bool Parse2 = int.TryParse(txtAge.Text, out ParseAge);           

        MainDataTable.CreateTable1();
        MainDataTable.EnterNewRows(ParseID, txtName.Text, ParseAge, txtAlignment.Text);

        this.NavigationService.Navigate(new Page0());

Page2.xaml.cs

public partial class Page2 : Page
{
    public Page2()
    {
        InitializeComponent();
    }

    private void SearchBtn1Clk(object sender, RoutedEventArgs e)
    {

        int IDFind = Convert.ToInt32(searchIdTxtBox.Text);
        DataRow foundRow = MainDataTable.dataMain.Rows.Find(IDFind);

        if (foundRow != null)
        {
            MessageBox.Show(foundRow[0].ToString());
        }

        else
        {
            MessageBox.Show("No Customer Found with ID:" + IDFind);
        }
    }
}

The values are stored in the table correctly from Page1.xaml.cs text input (I know this because I checked the rows after it ran), but when clicking search, this error occurs:

An unhandled exception of type 'System.Data.MissingPrimaryKeyException' occurred in System.Data.dll Additional information: Table doesn't have a primary key.

Answer 1

You don't have a column called ID . It's called CustID.Isn't it? Update this line and try again.

 dataMain.PrimaryKey = new DataColumn[] { dataMain.Columns["CustID"] };

Unless you are trying to accomplish something else.