Referring to a Control on a Worksheet

Fortunately, Excel lets us refer to an ActiveX control on a worksheet by using its name, without reference to the OLEObjects collection. For instance, if we place a command button on a worksheet, Excel will give it the default name CommandButton1. Both of the following lines set the height of this command button to 20 points:

ActiveSheet.OLEObjects("CommandButton1").Height = 20 ActiveSheet.CommandButtonl.Height = 20

Unfortunately, however, the properties and methods that we access in this manner are the properties and methods of the OLEObject, not the control itself. These properties are shown in Table 14-4.

Table 14-4. Members of the OLEObject object

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Enabled

PrintObject

Activate

Height

ProgId

Application

Index

Select

AutoLoad

Interior

SendToBack

AutoUpdate

Left

Shadow

Border

LinkedCell

ShapeRange

BottomRightCell

ListFillRange

SourceName

BringToFront

Locked

Top

Copy

Name

TopLeftCell

CopyPicture

Object

Update

Creator

OLEType

Verb

Cut

OnAction

Visible

Delete

Parent

Width

Duplicate

Placement

ZOrder

Thus, for instance, while we can set the Height property of the command button, we cannot set its Caption property in this way. That is, the code:

ActiveSheet.OLEObjects("CommandButton1").Caption = "ClickMe" will generate an error.

The way to reach the members of the control itself is to use the Object property of an OLEObject object, which returns the underlying control, and makes its properties and methods accessible. Thus, the following two lines each set the button's caption:

ActiveSheet.OLEObjects("CommandButton1").Object.Caption = "ClickMe" ActiveSheet.CommandButton1.Object.Caption = "ClickMe"

In addition to the standard properties available for ActiveX controls, the following properties can be used with ActiveX controls embedded in sheets in Microsoft Excel:

BottomRightCell

Returns a Range object that represents the cell that lies under the lower-right corner of the object.

LinkedCell

Returns or sets the worksheet range that is linked to the value of the control. Thus, if we place a value in the linked cell, the control will assume this value, and vice-versa.

ListFillRange

Returns or sets the worksheet range that is used to fill a list box control.

Placement

Returns or sets the way that the control is attached to the cells below it. The possible values are the XlPlacement constants: xlMoveAndSize, xlMove, and xlFreeFloating.

PrintObject

Prints the control when the worksheet is printed if this property is set to True. TopLeftCell

Returns a Range object that represents the cell that lies under the top-left corner of the object.

ZOrder

Returns the ZOrder position of the control.

Note also that Table 14-4 has some properties that are not properties of controls themselves. They relate to the OLEObject, which is the container for the control, and thus to the control's relationship with the worksheet. For instance, the code:

ActiveSheet.CommandButtonl.TopLeftCell.Address returns the address of the top-left cell of the worksheet that lies under the control (or rather, the control's container: the OLEObject).

As another example, the following code will locate the top-left cell under the command button and then scroll the active window so that this cell (and therefore the command button) is at the upper-left corner of the window:

Dim rng As Range

Set rng = ActiveSheet.CommandButtonl.TopLeftCell With ActiveWindow

.ScrollRow = rng.Row .ScrollColumn = rng.Column End With

It is important to note that some properties and methods of some Excel objects are disabled when an ActiveX control has the focus. For example, the Sort method of the Range object cannot be used when a control is active. Since a control on a worksheet remains active after it is clicked, the following code will fail:

Private Sub CommandButtonl Click

Range("A:A").Sort Key1:=Range("A:A") End Sub

(We will discuss the sort method in Chapter 19. Don't worry about that now.) This is one disadvantage of placing controls directly on worksheets.

Of course, one way to avoid this problem is to activate another object before calling the sort method. For instance, we can amend the previous code as follows:

Private Sub CommandButtonl Click Range("A:A").Activate Range("A:A").Sort Key1:=Range("A:A") CommandButtonl.Activate ' Optional

End Sub

It is also worth mentioning that if you save an Excel 97 or Excel 2000 workbook in Excel 5.0/95 Workbook file format, all ActiveX control information will be lost.

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