Page 226 - Excel Data Analysis

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EXCEL DATA ANALYSIS

VALIDATE INPUT FROM A DIALOG BOX

alidation ensures that the information that you validation code in that routine, you use a conditional
receive for analysis is accurate and of the correct statement, such as an If Then statement, to check the
V form. You must validate the values specified for properties of each control. This ensures that they have the
controls in a dialog box before passing the values back to appropriate values. For example, to ensure that the user
your procedure for two major reasons: First, you ensure that typed a string in the Name text field of the dialog box, you
the user specifies a value for a control. If the user forgets to can add the statement If TextBox1.Text = " " Then
select a control value, you can remind him or her to your procedure. This statement checks the Text
immediately. Second, which is probably the most important property for the specified TextBox control and ensures that
reason, you ensure that errors do not occur in your code it contains a value. If the property is empty (nothing is in it),
because the wrong type of data passed to a procedure. your VBA code can call the MsgBox function to display a
message telling the user to input a value.
You can create code that checks the user input for any
event that occurs on a UserForm. The easiest place to do so You also use the VBA validation functions to verify that a
is prior to closing the dialog box. For example, if you have a control contains the appropriate data type. For example, If
CommandButton control, such as an OK button, that passes Not IsNumeric(TextBox1.Value) Then ensures that
the values to global variables and closes the dialog box, this the user typed a number in a TextBox control.
is an ideal place to validate your data. When you place the

VALIDATE INPUT FROM A DIALOG BOX

⁄ On the UserForm, ■ Typically, an OK ■ The code window opens
double-click the control for command button is a good with the cursor at the
which you want to validate location for validating data beginning of the Click
the data values. values. procedure for the selected
control.
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