For a complete example, see Walkthrough: Adding Validation to a Dataset.
By default, each change to a column therefore raises four events.
From the toolbox, click and drag a Text Box between the div tags. In the properties window of the second text box, change the Back Color to Gray and change Read Only to True. From the toolbox, click and drag a Button below both text boxes.
Page Protected Sub Button1_Click(By Val sender As Object, By Val e As System.
This is done with the Length method at the end of Text Box1.
Because the dataset is part of your application (unlike the database backend), it's a logical place to build application-specific validation.
In that case, the event is not raised until the End Edit method has been called, when the Row Changing and Row Changed events are raised just once.
For more information, see Turn off constraints while filling a dataset.
If you already have a page set up skip to step 6, if you do not then start from step 1.
In solution explorer, right click on the solution and click Add New Item. Choose Visual Basic in installed templates and select Web Form. Change the text of the button to “Click for Length.” 8. You will see two text boxes, one with and the other gray, and a button with the text “Click for Length.” Double click on the button to take you to vb.