Читать книгу Excel Macros For Dummies - Dick Kusleika - Страница 18
Recording macros with relative references
ОглавлениеIn the context of Excel macros, relative means relative to the currently active cell. So you should use caution with your active cell choice — both when you record the relative reference macro and when you run it.
First, make sure the Chapter 1 Sample File.xlsx file is open. Then, use the following steps to record a relative-reference macro:
1 Click Use Relative References from the Developer tab, as shown in Figure 1-5.
2 Before recording, make sure cell A1 is selected.
3 Click Record Macro from the Developer tab.
4 Name the macro AddTotalRelative.
5 Choose This Workbook in the Macros In drop-down list.
6 Click OK to start recording.
7 Select cell A16 and type Total in the cell.
8 Select the first empty cell in Column D (D16) and type = COUNTA(D2:D15).
9 Click Stop Recording on the Developer tab to stop recording the macro.
FIGURE 1-5: Recording a macro with relative references.
At this point, you have recorded two macros. Take a moment to examine the code for your newly created macro.
Click Macros from the Developer tab to open the Macro dialog box. Here, choose the AddTotalRelative macro and click Edit.
Again, this opens the Visual Basic Editor to show you the code that was written when you recorded your macro. This time, your code looks something like the following:
Sub AddTotalRelative() ActiveCell.Offset(15, 0).Range("A1").Select ActiveCell.FormulaR1C1 = "Total" ActiveCell.Offset(0, 3).Range("A1").Select ActiveCell.FormulaR1C1 = "=COUNTA(R[-14]C:R[-1]C)" End Sub
Notice that there are no references to any specific cell ranges at all. Take a look at what the relevant parts of this VBA code really mean.
In line 2, Excel uses the Offset property of the active cell. This property tells the cursor to move a certain number of cells up or down and a certain number of cells left or right.
The Offset property code tells Excel to move 15 rows down and 0 columns across from the active cell (in this case, A1). Excel doesn’t select a cell with a specific address as it did when recording an absolute reference macro.
Between Offset and Select on the second line is Range(“A1”). This is Excel recording that you only selected one cell — the first cell of the range that is offset from the active cell. It’s a quirk of the Macro Recorder and isn’t necessary when you select only one cell. (The Macro Recorder records a lot of unnecessary code.) If you had selected, say A16:B17 instead of just A16, it would have recorded:
ActiveCell.Offset(15, 0).Range("A1:B2").Select
To see this macro in action, delete the total row for both tables and do the following:
1 Select cell A1.
2 Click Macros on the Developer tab.
3 Select the AddTotalRelative macro.
4 Click the Run button.
5 Select cell F1.
6 Click Macros on the Developer tab.
7 Select the AddTotalRelative macro.
8 Click the Run button.
Notice that this macro, unlike your previous macro, works on both sets of data. Because the macro applies the totals relative to the currently active cell, the totals are applied correctly.
For this macro to work, you simply need to ensure that
You’ve selected the correct starting cell before running the macro.
The block of data has the same number of rows and columns as the data on which you recorded the macro.
Hopefully, this simple example has given you a firm grasp of macro recording with both absolute and relative references.