Tải bản đầy đủ - 0 (trang)
Table 19-2. Excel Members That Return a Range Object

Table 19-2. Excel Members That Return a Range Object

Tải bản đầy đủ - 0trang

Dependents

Destination

DirectDependents

DirectPrecedents



PageRange

PageRangeCells

Precedents

Previous



Union

UsedRange

VisibleRange



Let us take a look at some of the more prominent ways to define a Range object.



19.2.1 Range Property

The Range property applies to the Application, Range, and Worksheet objects. Note that:

Application.Range



is equivalent to:

ActiveSheet.Range



When Range is used without qualification within the code module of a worksheet, then it is

applied to that sheet. When Range is used without qualification in a code module for a workbook,

then it applies to the active worksheet in that workbook.

Thus, for example, if the following code appears in the code module for Sheet2:

Worksheets(1).Activate

Range("D1").Value = "test"



then its execution first activates Sheet1, but still places the word "test" in cell D1 of Sheet2.

Because this makes code difficult to read, I suggest that you always qualify your use of the Range

property.

The Range property has two distinct syntaxes. The first syntax is:

object.Range(Name)



where Name is the name of the range. It must be an A1-style reference and can include the range

operator (a colon), the intersection operator (a space), or the union operator (a comma). Any dollar

signs in Name are ignored. We can also use the name of a named range.

To illustrate, here are some examples:

Range("A2")

Range("A2:B3")

Range("A2:F3 A1:D5")

Range("A2:F3, A1:D5")



' An intersection

' A union



Of course, we can use the ConvertFormula method to convert a formula from R1C1 style to A1

style before applying the Range property, as in:

Range(Application.ConvertFormula("R2C5:R6C9", xlR1C1, xlA1))



Finally, if TestRange is the name of a range, then we may write:

Range(Application.Names("TestRange"))



232



or:

Range(Application.Names!TestRange)



to return this range.

The second syntax for the Range property is:

object.Range(Cell1, Cell2)



Here Cell1 is the cell in the upper-left corner of the range and Cell2 is the cell in the lowerright corner, as in:

Range("D4", "F8")



Alternatively, Cell1 and Cell2 can be Range objects that represent a row or column. For

instance, the following returns the Range object that represents the second and third rows of the

active sheet:

Range(Rows(2), Rows(3))



It is important to note that when the Range property is applied to a Range object, all references are

relative to the upper-left corner cell in that range. For instance, if rng represents the second

column in the active sheet, then:

rng.Range("A2")



is the second cell in that column, and not cell A2 of the worksheet. Also, the expression:

rng.Range("B2")



represents the (absolute) cell C2, because this cell is in the second column and second row from

cell B1 (which is the upper-left cell in the range rng ).



19.2.2 Cells Property

The Excel object model does not have an official Cells collection nor a Cell object. Nevertheless,

the cells property acts as though it returns such a collection as a Range object. For instance, the

following code returns 8:

Range("A1:B4").Cells.Count



Incidentally, Cells.Count returns 16,777,216 = 256 * 65536.

The Cells property applies to the Application, Range, and Worksheet objects (and is global).

When applied to the Worksheet object, it returns the Range object that represents all of the cells

on the worksheet. Moreover, the following are equivalent:

Cells

Application.Cells

ActiveSheet.Cells



When applied to a Range object, the Cells property simply returns the same object, and hence does

nothing.



233



The syntax:

Cells(i,j)



returns the Range object representing the cell at row i and column j. Thus, for instance:

Cells(1,1)



is equivalent to:

Range("A1")



One advantage of the Cells property over the Range method is that the Cells property can accept

integer variables. For instance, the following code searches the first 100 rows of column 4 for the

first cell containing the word "test." If such a cell is found, it is selected. If not, a message is

displayed:

Dim r As Long

For r = 1 To 100

If Cells(r, 4).Value = "test" Then

Cells(r, 4).Select

Exit For

End If

Next

If r = 101 then MsgBox "No such cell."



It is also possible to combine the Range and Cells properties in a useful way. For example,

consider the following code:

Dim r As Long

Dim rng As Range

With ActiveSheet

For r = 1 To 100

If Cells(r, r).Value <> "" Then

Set rng = .Range(.Cells(1, 1), .Cells(r, r))

Exit For

End If

Next

End With

rng.Select



This code searches the diagonal cells (cells with the same row and column number) until it finds a

nonempty cell. It then sets rng to refer to the range consisting of the rectangle whose upper-left

corner is cell A1 and whose lower-right corner is the cell found in this search.



19.2.3 Column, Columns, Row, and Rows Properties

The Excel object model does not have an official Columns or Rows collection. However, the

Columns property does return a collection of Range objects, each of which represents a column.

Thus:

ActiveSheet.Columns(i)



234



is the Range object that refers to the ith column of the active worksheet (and is a collection of the

cells in that column). Similarly:

ActiveSheet.Rows(i)



refers to the ith row of the active worksheet.

The Columns and Rows properties can also be used with a Range object. Perhaps the simplest way

to think of rng.Columns is as the collection of all columns in the worksheet reindexed so that

column 1 is the leftmost column that intersects the range rng. To support this statement, consider

the following code, whose results are shown in Figure 19-1:

Dim i As Integer

Dim rng As Range

Set rng = Range("D1:E1, G1:I1")

rng.Select

MsgBox "First column in range is " & rng.Column

MsgBox "Column count is " & rng.Columns.Count



' Displays 4

' Displays 2



For i = -(rng.Column - 2) To rng.Columns.Count + 1

rng.Columns(i).Cells(1, 1).Value = i

Next



Figure 19-1. A noncontiguous range



Note that the range rng is selected in Figure 19-1 (and includes cell D1). The Column property of

a Range object returns the leftmost column that intersects the range. (Similarly, the Row property

returns the topmost row that intersects the range.) Hence, the first message box will display the

number 4.

Now, from the point of view of rng, Columns(1) is column number 4 of the worksheet (column

D). Hence, Columns(0) is column number 3 of the worksheet (column C) which, incidentally, is

not part of rng. Indeed, the first column of the worksheet is column number

-(rng.Column - 2)



which is precisely why we started the For loop at this value.

Next, observe that:

rng.Columns.Count



is equal to 2 (which is the number displayed by the second message box). This is a bit unexpected.

However, for some reason, Microsoft designed the Count property of r ng.Columns to return

the number of columns that intersect only the leftmost area in the range, which is area D1:E1. (We

will discuss areas a bit later.) Finally, note that:

rng.Columns(3)



is column F, which does not intersect the range at all.



235



As another illustration, consider the range selected in Figure 19-2. This range is the union B4:C5,

E2:E7.

Figure 19-2. The range as a union



The code:

Dim rng As Range

Set rng = Range("B4:C5, E2:E7")

MsgBox rng.Columns(1).Cells(1, 1).Value



displays a message box containing the x shown in cell B4 in Figure 19-2 because the indexes in

the Cells property are taken relative to the upper cell in the leftmost area in the range.

Note that we can use either integers or characters (in quotes) to denote a column, as in:

Columns(5)



and:

Columns("E")



We can also write, for instance:

Columns("A:D")



to denote columns A through D. Similarly, we can denote multiple rows as in:

Rows("1:3")



Since a syntax such as:

Columns("C:D", "G:H")



does not work, the Union method is often useful in connection with the Columns and Rows

methods. For instance, the code:

Dim rng As Range

Set rng = Union(Rows(3), Rows(5), Rows(7))

rng.Select



selects the third, fifth, and seventh rows of the worksheet containing this code or of the active

worksheet if this code is in a workbook or standard code module.



236



19.2.4 Offset Property

The Offset property is used to return a range that is offset from a given range by a certain number

of rows and/or columns. The syntax is:

RangeObject.Offset(RowOffset, ColumnOffset)



where RowOffset is the number of rows and ColumnOffset is the number of columns by

which the range is to be offset. Note that both of these parameters are optional with default value 0,

and both can be either positive, negative, or 0.

For instance, the following code searches the first 100 cells to the immediate right of cell D2 for

an empty cell (if you tire of the message boxes, simply press Ctrl-Break to halt macro execution):

rng As Range

i As Integer

rng = Range("D2")

i = 1 To 100

If rng.Offset(0, i).Value = "" Then

MsgBox "Found empty cell at offset " & i & " from cell D2"

End If

Next



AM

FL

Y



Dim

Dim

Set

For



19.3 Additional Members of the Range Object

Let us now take a quick look at some additional members of the Range object. (Please refer to

Table 19-1 for an indication of which members are discussed in this section.)



TE



19.3.1 Activate Method



The Activate method will activate (or select) the range to which it is applied. The Activate method

applies to a variety of other objects besides the Range object, such as the Window object, the

Worksheet object, and the Workbook object.



19.3.2 AddComment Method

This method adds a Comment object (i.e., a comment) to the single-cell range. Its syntax is:

RangeObject.AddComment(Text)



where Text is the text of the comment. For instance, the code:

Dim

Dim

Set

Set



rng As Range

c As Comment

rng = Range("B2")

c = rng.AddComment("This is a comment")



adds a comment to cell B2 with the text "This is a comment." Note that if RangeObject consists

of more than a single cell, a runtime error results.



19.3.3 Address Property (Read-Only String)



237 ®

Team-Fly



Tài liệu bạn tìm kiếm đã sẵn sàng tải về

Table 19-2. Excel Members That Return a Range Object

Tải bản đầy đủ ngay(0 tr)

×
x