Range Objects and the ActiveCell

Transcription

1 Range Objects and the Active Review Objects have two important features that we can make use of Properties Methods Talk does not cook rice. Chinese Proverb 2 Review Review There is a very precise syntax to do this. A complete form of the syntax would be Page 116 in the reference text gives more details on this command syntax and structure

2 Review Review If the answer is true, then we do everything down to the Else statement If the answer is false, then we do everything starting just below the Else down to the End If We have a visual way to represent the way that the program flows through this code 5 6 Review Review The statements we are going to use are known as For Each Next statements They operate on elements or objects in a collection Page 113 in the reference text gives more details on this command syntax and structure. And finally we need to end the loop To make it easier to read we include the variable we were using to hold the objects 7 8 2

3 Review This doesn t change the execution of the code but it helps to see just what is within each block and makes error isolation easier. Range Objects A Range object is an object containing a collection of cells (and their properties) as specified by the argument given to the object 9 10 Range Objects Range Objects When we wanted to refer to a specific worksheet within a workbook we used an argument to the Worksheets collection object to specify exactly which worksheet you want to work with. Now if we want to work with a continuous block of cells on a worksheet, we can make a collection of those cells using the Range property of a worksheet Worksheets( Harpo"). Worksheets( Harpo")

4 Range Objects For example, if we wanted to work with the cells in the block from A1 to D4 on the worksheet named Harpo, the way to make a collection of those cells would be Worksheets( Harpo").Range( A1:D4 ) Range Objects Notice that just like selecting a specific worksheet from all the possible worksheets in the workbook we have selected a specific group of cells from all the possible cells on the worksheet named Harpo Worksheets( Harpo").Range( A1:D4 ) Range Objects Range Objects We can manipulate the properties of the cells within the collection just as we would manipulate the properties of individual cells Worksheets( Harpo").Range( A1:D4 ) As an example of how this works, we can write a macro similar to the one we worked on last week but rather than using our cursor to select the cells we are considering we will use the Range object to collect the cells. Worksheets( Harpo").Range( A1:D4 )

5 Range Objects We will make a new macro that is almost exactly like to one from last week. Range Objects In this case, my workbook contains three worksheets named Harpo, Chico, and Zeppo Range Objects Here I am specifically deciding to work on the sheet named Harpo I don t have to open the sheet and make it active Range Objects I also don t have to use my cursor to make a collection of cells to work on The Range property is used to make the selection

6 Range Objects In this snapshot, the cell selected by the cursor is the cell L8 so if we were using the Selection property this would be the object we would work on Range Objects Using the Range object as we set it up, we will work on the block of cells from H8 to J Range Objects After we execute the macro, notice that the changes are made to the block described by the Range object and not the selected cell. Range Objects The use of the range object allows us to manipulate different blocks of cells on the spreadsheet without having to make the selection of the cells with the cursor. This is really useful when we have information in the spreadsheet that we want to address that never changes position in the sheet

7 Formula Property One of the most useful properties of a cell is the Formula property This allows us to make calculations with a macro that mimic how we make calculations on the worksheet Formula Property For example, if we wanted to fill a range of cells from H8 to J13 with random numbers between 0 and 50 we could use the following macro Formula Property Now if you go to the worksheet Chico you can see that there are random numbers displayed in all the cells Formula Property If you select any cell, you can also see that the formula =Rand()*50 is in each cell

8 Formula Property This is different than changing the Value property of the cell This places the result of the calculation in the cell, not the formula to do the calculation Formula Property For example if we add the line into the macro Formula Property Formula Property We get the results of the calculation placed into each cell But when we look at the formula stored in the cell

9 Formula Property All we have is the constant that resulted from the calculation, not the formula that developed the result. The Active Property The Active Property is the property of a worksheet which returns a Range object containing the properties of the cell that is currently active on that worksheet The Active Property The Active Property The Active is the selected cell in the worksheet by a cursor selection or it is the first cell selected when a range of cells are selected. The Active is the selected cell in the worksheet by a cursor selection Here the active cell is cell H8. Notice that the active cell also appears in the name box

10 The Active Property The Active Property The Active is it is the first cell selected when a range of cells are selected. We can make use of the Active property to change the properties of the selected cell. This range of cells was selected by selection cell J14 first and then dragging the cursor until all the cells highlighted were selected. Notice that although all the cells selected are surrounded by the dark line, only the active cell does not have the blue-grey tint The Active Property The Active Property Here is a macro that will act only on the selected cell. If we select the range of cells, the macro will still only operate on the active cell

11 The Active Property If we select the range of cells, the macro will still only operate on the active cell LAB 41 We have seen a number of ways that we can pick an individual cell to work with We can select a cell by identifying its location on the sheet and using a Range object to select it. Worksheets("Chico").Range( A5")

12 We can select a cell by first selecting the cell with the cursor on the worksheet and then using the Active object Active We can work with individual cells that are part of a selection by working through a collection of cells using a For Each loop. For Each in In Worksheets("Harpo").Range("H8:J13") If in.value < 20 Then With in.font.name = "Tahoma".Size = 14.Bold = True End With in.interior.color = vbgreen End If Next in In each case, we have selected one cell on the sheet to work with We can now use another property to work with cells in reference to the currently selected cell The property that we are going to use is the Offset property Remember that this is a property of the currently selected cell and does not stand alone

13 The Offset property allows us to work with cells in reference to the location of the currently selected cell by moving a number of rows and/or columns from the currently selected cell We can move both left and right from the currently selected cell in terms of columns and up and down from the currently selected cell in terms of rows We do this by giving the Offset property arguments Arguments with negative signs Move to the left for columns Move up for rows Arguments with positive signs Move to the right for columns Move down for rows Arguments of 0 Stay in the currently selected cell s row or column

14 For example if the currently selected cell is the cell D5 then.offset(1,1) would refer to the cell in E6.Offset(-1,1) would refer to the cell in E4.Offset(1,-1) would refer to the cell in C6.Offset(-1,-1) would refer to the cell in C4.Offset(-1,-1).Offset(0,-1).Offset(1,-1).Offset(-1,0) Active.Offset(1,0).Offset(-1,1).Offset(0,1).Offset(1,1) Even though I have just shown examples of arguments of 1s, 0s, and -1s, you are not limited to these values If you go past the boundaries of the worksheet, the argument will default to the boundary As an example of how to use these, we can make a handy math table for a high school student The first column of the table will be numbers The next column will be the square of the numbers The next column will be the cube of the numbers

15 The next column will be the square root of the numbers The next column will be the cube root of the numbers The last column will be the log of the numbers Since we are working down a column of numbers, it is appropriate to use the For Each construct and to select the original column as our Selection object So before we run our macro, we would need to select the column of numbers from R9 to R20 This becomes our Selection Object

16 We can start the code by setting up the loop to go through the individual cells Since we want to look at the contents (.value) of each cell, we will use this property For the Square column, we will take the value of the selected cell, square it, and make that the value of the cell offset by 1 column For the Square column, we will take the value of the selected cell, square it, and make that the value of the cell offset by 1 column

17 The right side of the equal sign reads Take the value property from the currently selected cell and square it (the ^ is the exponentiation operator) Then we take the currently selected cell, offset it by 1 column to the right and set the value property of that cell (the offset) to what was calculated on the right side of the = When we run the code we get We can extend this code for the rest of the operations

18 We can extend this code for the rest of the operations And we when we execute the code we have There is a special property that can make developing a calculation in a sheet easier. Normally we denote rows as 1 through And columns as A through IV So cells are addressed using labels like A1, B360 Older speadsheet programs used numbers for both rows and columns While the new forms are much easier to read they don t always make programming as easy The reason for this is it is very easy to count up and down numerically and so move through cells

19 You have to be careful to understand that you are using a special formula property and not to just use the Formula property They act differently and take different arguments The R1C1 property allows you to address cells relative to the currently selected cell in a formula The Offset property is not available in a formula When we use the.formula property we set up an expression using cell addresses in the typical form A1, B2, etc. The.FormulaR1C1 property allows us to develop formulas that address cells relative to the position of the currently selected cell For example if cell U10 is the currently selected cell we could use cells in reference to that cell by determining how many rows and columns away the other cell is

20 The form for the.formular1c1 property uses to address cells is R[n]C[m] rather than the familiar A1 type form The R[n] designates how many rows away from the currently selected cell the cell to be used is The C[m] designates how many columns away from the currently selected cell the cell to be used is Now we can look at the program we just developed for the table of mathematical calculations and rather than manipulate the value property we will manipulate the formulas that we store in the cells Our original code looked like this Now we want to manipulate the.formula property in the cells rather than the.value property

21 For the first row of the table, the number was in the cell R9 So we could rewrite our program using the.formula property Unfortunately, the results were not what we wanted Every calculation referred back to cell R

22 Unlike copying formulas with relative references, the formula in this case did not change. The.FormulaR1C1 property can allow us to get around this We can rewrite our code using the.formular1c1 property as In the first in.offset line of the code The formula that goes into the cell says that we move 0 rows from the row that the cell is in and back 1 column When we move 0 we don t need the argument

23 So for the first selected cell in R9, the formula will go into cell S9 because of the Offset(0,1) The formula will take the value one column to the left of S9 and in the same row to make the calculation If we run this code we have Which is what we had originally The big difference comes when we look at what is in the cells on the sheet

24 The top part comes from the most recent run of the macro Notice that it has put all the correct cell references into the cells The bottom part comes from the very first time we developed this code It only contains the values and not how they were calculated Each of these methods will have their own place in your sheet development Lab Assignment This lab is to be submitted by the end of the lab time (5:20 PM) The grading metric is as follows

25 Lab Assignment Correct language syntax 10 points Correct operation 10 points Accurate answers 10 points Concise programming style 5 points Readability and program flow 5 points Testing and verification 5 points Lab Assignment Each week, as the project manager, you receive a list of the people who worked on your project, how many hours they worked, and the hourly rate that they are paid Lab Assignment Lab Assignment Your macro will calculate how much each person was paid (total) during the time period and place it in a column next to the Rate column. If a person worked more than 40 hours, they are paid 1.5 times their normal rate for the hours over 40 hours If a person worked more than 50 hours, they are paid 2 times their normal rate for the hours over 50 hours Be careful not to double count here

26 Lab Assignment The format for this column should be currency If a person works more than 50 hours, in the column next to their pay, place the phrase More Than 50 Hours Submit your worksheet and macro in the LAB1Submission folder on the UMDrive with the title L1S07yourname.xls