Consider this code:
txtLastModifyUserID.DataBindings.Add("Text", c_bsDataSetSource, "LastModifyUserID");
txtLastModifyUserID.Text = "1234";
Why cannot the source be updated?
The DataBinding doesn't usually write the value until after the control starts to lose focus. Since you are updating the TextBox programmatically, the DataBinding doesn't know there is something to update.
The way you wrote your code, you would have to call the WriteValue()
method yourself (assuming only 1 databinding exists on the TextBox):
txtLastModifyUserID.DataBindings.Add("Text", c_bsDataSetSource, "LastModifyUserID");
txtLastModifyUserID.Text = "1234";
txtLastModifyUserID.DataBindings[0].WriteValue();