If one cell changes vba excel

How to run a macro when certain cells change in Excel

Summary

In Microsoft Excel, you can create a macro that is called only when a value is entered into a cell in a particular sheet or in any sheet that is currently open.

Note, however, that you should not call macros unnecessarily because they slow down the performance of Excel.

More information

Microsoft provides programming examples for illustration only, without warranty either expressed or implied. This includes, but is not limited to, the implied warranties of merchantability or fitness for a particular purpose. This article assumes that you are familiar with the programming language that is being demonstrated and with the tools that are used to create and to debug procedures. Microsoft support engineers can help explain the functionality of a particular procedure, but they will not modify these examples to provide added functionality or construct procedures to meet your specific requirements. In many instances, a macro should run only when a certain number of cells have values entered into them (referred to as the «key cells» in this document). In order to prevent a large macro from running every time a value is entered into a cell of a sheet, you must check to see if the ActiveCell is one of the key cells. To accomplish this, use the Intersect method on the ActiveCell and the range containing the key cells to verify the ActiveCell is one of the key cells. If the ActiveCell is in the range containing the key cells, you can call the macro.

To create the Visual Basic macro:

Right-click the Sheet1 tab and then click View Code.

The module sheet behind Sheet1 is opened.

Type the following code into the module sheet:

Click Close and Return to Microsoft Excel on the File menu.

When you type an entry in cells A1:C10 on Sheet1, a message box is displayed.

Источник

How to Tell if a Cell Changed with VBA

There are times when you want to run a macro when a cell changed. Maybe you want to do some special calculation when a cell changes. Or maybe you’d like to change the font to all uppercase. Or maybe you want to present your users with more meaningful data validation messages. Whatever the case may be, you can use Excel’s Worksheet_Change event in VBA to help accomplish your automation needs.

What is aВ Worksheet_Change Event?

The Worksheet_Change event is a special event that happens in Excel when a cell (or multiple cells) has changed in a specific worksheet. ThisВ includes when a cell is created, updated, or deleted.

This does not include changes like:

• Formatting changes (font size, cell size, font/cell color, conditional formatting, etc.)
• A cell changedВ because the calculation was updatedВ (this is a different event called theВ Worksheet_Calculate event)
• Selecting a cell (this is another event called Worksheet_SelectionChange event)

Does this article help you? If so, please consider supporting me with a coffee ☕️

How do I use this Event?

Open up the VB Editor ( Alt+F11 in Windows or Tools->Macros->Visual Basic Editor on Mac). In the Project window, you’ll see where the workbook and worksheets are:

Double-click on the Sheet1 object and pasteВ the following code:

This is a very basic example of how to start using the Worksheet_Change event. This method is what’s called an Event Handler, which simply means that “this is the method I want to use for handling when X event happens.”

Whenever a cell changes as we described above,В Excel will execute theВ Worksheet_Change event and pass in the cells that were changed through the target object. We use this target object to take a look at which cells were affected.

To invoke this event, go to the Sheet1 worksheet and make a change to a cell. Then, in the VBE Immediate Window ( Ctrl+G on Windows or in Mac this window should always be visible) you will see some text appear each time the event is fired. Here’s an example:

Notice that whenever I change a cell, the Immediate Window shows some text based on the cell I changed. Also note that if I change multiple values at the same time, like cells A1:A2 , then the target object contains that specific range and not just a single cell or array of cells.

It’s important to note that you can work with a range of cells within the same target object that is passed in to the event handler. We’ll take a look at this in the following sections.

How do IВ check if the Cell Changed within a Specific Range?

The target object is simply a range object that describes which cell changed (or set of cells). As shown before, you can get either a single cell, or multiple cells passed into the range (even several range areas, but that’s a topic for another post).

When you want to see if the items that changed fall within another range, you can use the following code:

Here is an example of how this works:

I use the Intersect() function to determine if the target range is within another range that I defined «A1:B3» . The result of Intersect will beВ the range of cells that intersected, if any. The Intersect() function returns Nothing when no intersection is found. ThisВ is why we check for that in the If statement.

Notice that when I select A2:C4 , the target object has the range A2:C4 , but the intersection range has A2:B3 . This is an important distinction to make when working with an intersection. If you used the target range instead of the intersection range, you may end up working with the wrong data (i.e. cells C2:C4 in this case).

How to avoid infinite loops

Now that you know how to monitor changes in your worksheet and act on them, let’s consider what would happen if you make a change to a cell within the Worksheet_Change event.

Consider the following code:

In the For loop, I go through each cell that was effected and prepend the cell with some text.

However, changing the cell value will cause the Worksheet_Change event to fire again, which will take the new value of the text and again prepend it with some more text, and on and on this will go until either Excel crashes or you close the app.

To avoid this, we have to temporarily disable events from firing, make the change to the cell, then re-enable the events.

Application.EnableEvents is a boolean property that you can read / write. When we set this to False , any events that would normally happen (like a Worksheet_Change event) will be suppressed. When we turn this back to True , we will get the events to happen as we expect.

Wow, you read the whole article! You know, people who make it this far are true learners. And clearly, you value learning. Would you like to learn more about Excel? Please consider supporting me by buying me a coffee (it takes a lot of coffee to write these articles!).

Written by Joseph who loves teaching about Excel.

Источник

VBA Worksheet Change Event – Run a Macro When a Cell Changes

Worksheet_Change Event

You may want to run a macro when a cell changes. A popular use of this ability is to have custom code validate a cell after a change is made. It’s easy to do this by using the worksheet objects change event.

In the Visual Basic Editor you must first double click the sheet name where the cell changes that activates the macro. This opens the code window for that sheet object. In this case I wanted to run a macro when a cell in Sheet1 changes.

After opening the code window for the Worksheet you place your code in the Worksheet_Change event. The following example will display a message box if the contents of cell A1 change. First the subroutine fires if any cell changes, then the use of an IF..Then statement will run the code only if cell A1 was the cell that changed based on the If…Then.

You can place your code directly in the Worksheet_Change subroutine or call another macro from there.

VBA Coding Made Easy

Stop searching for VBA code online. Learn more about AutoMacro – A VBA Code Builder that allows beginners to code procedures from scratch with minimal coding knowledge and with many time-saving features for all users!

VBA Code Examples Add-in

Easily access all of the code examples found on our site.

Simply navigate to the menu, click, and the code will be inserted directly into your module. .xlam add-in.

Источник

Calling a custom built VBA function when an Excel cell is changed

I’d like to preface this question by saying that I am an undergrad in college who knows C++ and has a very rudimentary understanding of VBA.

Now then, as stated in the title I need some help configuring some VBA code for an Excel worksheet so that whenever a cell in a column (specifically the D column) is modified it will automatically update other cells within the same row.

Essentially I want this to work such that when user Bob modifies cell D26 (for example) it will call a custom function I built and insert that code into cell B26 and then repeat with a different function for cell C26.

However, this function needs to be such that if cell D27 is modified it will only modify other cells in row 27, leaving row 26 and prior or subsequent rows alone until such a time as this function is called in D28 and so on.

I’m not entirely sure if this is even possible but I’d be gracious if anybody could help me configure this.

The code I built/scavenged from the internet for my custom function is this: http://pastebin.com/RE0V2nrT

The second function I want to call for this project is the =TODAY() function built into Excel.

The code I have scraped together so far for checking if the cell has changed is this: http://pastebin.com/S5E8cmty

If anybody could help me understand how to write what I’m looking for it would be much appreciated. If you have a different approach to solving the issue I would also love to hear it. as long as you could help me then enact your solution, haha!

Anyways, thanks to anybody who replies.

1 Answer 1

Have a look at the worksheet events available within the Excel namespace. For this, you would use the Change event

If you double click on the worksheet you want to monitor, you can insert a Worksheet_Change sub. Then you can use the intersect function to check if the changed cell was within your range you want to monitor (e.g. D:D).

You can specify which cells you want to change. Here I just gave an example based on what you asked. This will put the output of your function into cell B[R] and put the current date into cell C[R]. Note that I’m using the Now() function since there is no Today() function in VBA. Since this returns both date and time, I’m using the Format function to get just the date.

Just for fun, let’s go a little further into the object model and first get the Worksheet object to which the target range belongs. This is not 100% necessary — you could just rely on ActiveSheet. Now, you probably don’t need to do this, and it’s mostly just for fun, but it’s also worth noting that if you were programmatically making changes to this sheet, but had not activated this sheet first (so another sheet was active) and you had not turned off EnableEvents you would get some strange results 🙂

Explanation

Worksheet change sub is declared like this. The Worksheet objects have pre-defined method stubs for events. Kind of like an interface, though not listed as an interface in the documentation. If you think of it in that concept, this is your event handshake. See the link I posted above for a list of the worksheet events available.
Private Sub Worksheet_Change(ByVal Target As Range)

In the next lines we are getting the worksheet object to which the object named Target belongs. You can see in the sub declaration that Target is declared as an object of the type Range . If you check out the Worksheet object (linked above) or the Range object documentation you’ll see that the range object is a member of the worksheet object, and the documentation kind of sucks here, but FYI the worksheet object is contained within the Parent property. Now, originally I had my code using the ActiveSheet member of the Application object — but I’ve edited it for the reasons given in my answer above.

I use With Blocks to save typing the same Worksheet reference in multiple places. A With block just lets me access the members of the namespace specified (in this case members of the object TargetSheet ) by typing .SomeMember . The compiler understands that every reference like this refers to whatever is specified in the opening With . statement. I personally like this for readability, but I also recommend it for maintenance (change reference one place vs many). Also having a single reference gives a tiny, insignificant, probably not worth mentioning performance boost over multiple references as well.

Next we check whether or not Target is within the range of cells we want to watch. The If. Then should look familiar enough. For our condition we use the boolean operator Not to check if the result of the intersect function (linked above) Is Nothing. The reason we do this is to check if the return is allocated. If an object is allocated the Not SomeObject Is Nothing condition will evaluate to False . If the object is not allocated (i.e. our Intersect function failed to return anything) then the statement evaluates to True . So, from the Intersect function documentation we know that if our return is allocated, the ranges intersect and the intersecting range object was returned. Thus if we want to know if they intersect, we can just check for the opposite of a failure.

If Not Application.Intersect(Target, .Range(«D:D»)) Is Nothing Then

The next lines then just execute some code on cells within the same row as Target . We use the Cells member of the worksheet object to specify what cells to modify. Per the documentation, the default property for Cells is Item which lets us access a range object through a row and column index like this: .Cells[Row,Column] . So, I simply use the row of our Target object and the column you wanted (column «A» =1, «B»=2, etc. You can see this by changing excel properties to R1C1 reference style if you are interested).

.Cells(Target.Row, 2) = ExtractWindowsUser()

And I think the Format() and Now() functions are pretty well explained in the documentation.

Источник

Worksheet_Change Event

You may want to run a macro when a cell changes. A popular use of this ability is to have custom code validate a cell after a change is made. It’s easy to do this by using the worksheet objects change event.

In the Visual Basic Editor you must first double click the sheet name where the cell changes that activates the macro. This opens the code window for that sheet object. In this case I wanted to run a macro when a cell in Sheet1 changes.

After opening the code window for the Worksheet you place your code in the Worksheet_Change event. The following example will display a message box if the contents of cell A1 change. First the subroutine fires if any cell changes, then the use of an IF..Then statement will run the code only if cell A1 was the cell that changed based on the If…Then.

Private Sub Worksheet_Change(ByVal Target As Range)



If Target.Address = "$A$1" Then

     MsgBox "This Code Runs When Cell A1 Changes!"

End If



End Sub

You can place your code directly in the Worksheet_Change subroutine or call another macro from there.