c# winform:如何在DataGrid最后一行中插入一条数据？

当按Add按钮时DataGrid在最后新增一行空白行，但是如果DataGrid有排序时，新增的行不一定跑到最后一行了，有什么好办法解决？感谢高手指点。

public void New()
{
textBox1.Text = "";
textBox2.Text = "";
textBox3.Text = "";
textBox4.Text = "";
tbComment.Text = "";
textBox1.ReadOnly = false;
textBox2.ReadOnly = false;
textBox3.ReadOnly = false;
textBox4.ReadOnly = false;
tbComment.ReadOnly = false;
textBox1.Focus();
DataRow NewRow = ds.Tables[0].NewRow();
ds.Tables[0].Rows.Add(NewRow);
dataGrid1.CurrentRowIndex = myBind.Count-1;
dataGrid1.Select(myBind.Count-1);
dataGrid1.Enabled = false;
}