我喜欢ryantpayton的方法，但这里是你的code修改为：

I like ryantpayton's method, but here's your code revised:

public class HelloWorldWeb : WebPart
{
    public HelloWorldWeb()
    {
        CreateTable();
    }
    private void CreateTable()
    {
        //table Cells Controls
        TextBox txt1 = new TextBox();
        txt1.Height = 19;
        TextBox txt2 = new TextBox();
        txt2.Height = 19;
        TextBox txt3 = new TextBox();
        txt3.Height = 19;
        DateTimeControl dt1 = new DateTimeControl();
        dt1.DateOnly = true;
        DateTimeControl dt2 = new DateTimeControl();
        dt2.DateOnly = true;
        Button btnAdd = new Button();
        btnAdd.Text = "Create New Row";
        btnAdd.Click += new EventHandler(btnAdd_Click);


        //Declaration one Row and Five Cells(with controls)
        Table myTbl = new Table();
        myTbl.ID = "tblUsers";
        TableRow tRow = new TableRow();

        TableCell tCellOne = new TableCell();
        tCellOne.Controls.Add(txt1);
        tRow.Cells.Add(tCellOne);

        TableCell tCellTwo = new TableCell();
        tCellTwo.Controls.Add(dt1);
        tRow.Cells.Add(tCellTwo);

        TableCell tCellThree = new TableCell();
        tCellThree.Controls.Add(dt2);
        tRow.Cells.Add(tCellThree);

        TableCell tCellFour = new TableCell();
        tCellFour.Controls.Add(txt2);
        tRow.Cells.Add(tCellFour);

        TableCell tCellFive = new TableCell();
        tCellFive.Controls.Add(txt3);
        tRow.Cells.Add(tCellFive);

        myTbl.Rows.Add(tRow);

        this.Controls.Add(myTbl);
        this.Controls.Add(btnAdd);

    }

    private void AddNewRow()
    {
        Table tbl = (Table)this.FindControl("tblUsers");

        //table Cells Controls
        TextBox txt1 = new TextBox();
        txt1.Height = 19;
        TextBox txt2 = new TextBox();
        txt2.Height = 19;
        TextBox txt3 = new TextBox();
        txt3.Height = 19;
        DateTimeControl dt1 = new DateTimeControl();
        dt1.DateOnly = true;
        DateTimeControl dt2 = new DateTimeControl();
        dt2.DateOnly = true;

        TableRow tRow = new TableRow();

        TableCell tCellOne = new TableCell();
        tCellOne.Controls.Add(txt1);
        tRow.Cells.Add(tCellOne);

        TableCell tCellTwo = new TableCell();
        tCellTwo.Controls.Add(dt1);
        tRow.Cells.Add(tCellTwo);

        TableCell tCellThree = new TableCell();
        tCellThree.Controls.Add(dt2);
        tRow.Cells.Add(tCellThree);

        TableCell tCellFour = new TableCell();
        tCellFour.Controls.Add(txt2);
        tRow.Cells.Add(tCellFour);

        TableCell tCellFive = new TableCell();
        tCellFive.Controls.Add(txt3);
        tRow.Cells.Add(tCellFive);

        tbl.Rows.Add(tRow);
    }

    void btnAdd_Click(object sender, EventArgs e)
    {
        AddNewRow();
    }
}