Step By Step Guide to List Events Handling in SharePoint
The objective of this article is to give a very basic explanation of how to catch an event on a SharePoint list and deploy them programmatically. I will achieve in this article "User will get error message; whenever any item will get deleted from a particular list ".
What is Event?
Event handling gives developer the ability to catch certain user actions in code and react programmatically.
Steps to handle List in SharePoint
Step 1: Creating the class
- Create a class that will extend SPListEventReceiver or SPItemEventReceiver class. These are classes of Microsoft.SharePoint.dll assembly.
- Sign the class library with strong name.
- Deploy the class library to GAC
- Deploy the event receiver assembly.
Create a new project of type class library. I am giving name of the project eventhandlersampleclasslibrary
. You are free to give any name of your choice. I am extending the SPItemEventReceiver.
The purpose of extending this class is that I am going to handle events on a particular item of a list.Note: I am going to handle the Item Deleting event on a particular list. I will not allow any user to delete any item in that list.
public class Class1 :SPItemEventReceiver
public override void ItemDeleting(SPItemEventProperties properties)
string errorMessage = "Please Do not delete ; you are not supposed too ";
properties.ErrorMessage = errorMessage;
properties.Cancel = true;
}Step 2: Signing the class name
Step 3: Deploying the class library to GAC
- Right click on Project and then Properties.
- Now click on signing tab.
- Check the Sign the Assembly checkbox.
- For selecting the Strong name key file , select New option from drop down
- Give a strong name. I am giving the name abc here.
- Make sure Password protection checkbox is unchecked.
- After this; you would be able to see abc.snk in solution explorer.
Gacutil /I [Complte path of dll of class]
- Open the command prompt
- Change directory to Program Files\Common Files\ Microsoft Shared\ web server extension\12\Bin
- Type the command gacutil /I complete path of the dll of class created as eventreceiver class in step1
The above command will deploy the dll in Gac assembly.Step 4: Deploy the Event Receiver assembly
This step could be done I either in three ways
- Through code
- Through Stsadm command ( Features)
- Through the content types
I am going to deploy using the program.
- Either create another project of console type or add class to any existing project.
- Add the reference of SharePoint dll.
- Return the Site Collection using SPSite.
- Return the top level site using SPWeb.
- Return the list using SPList.
- Add the event in the list using SPEventRecieverDefinition.
- Dhan is the name of the list which event I am going to capture.
- Class name is the name of the class, you created in step1.
- Assembly is the assembly information of the dll in GAC. To get information about dll in GAC follow below steps.
a. Go to Start -> Run
b. Type Assembly
c. Window will open; seek for dll you added.
d. Right click there and go to properties for all the information.
- In Type select ItemDeleting.
- Then call the update method.
static void Main(string args)
SPSite spsite = new SPSite("http://adfsaccount:2222/");
SPWeb mysite = spsite.OpenWeb();
SPList theList = mysite.Lists["Dhan"];
SPEventReceiverDefinition newReceiver = theList.EventReceivers.Add();
newReceiver.Class = "eventhandlersampleclasslibrary.Class1";
newReceiver.Assembly = "eventhandlersampleclasslibrary,Version=220.127.116.11,Culture=neutral,PublicKeyToken=fd7c0a9671b2ae14";
newReceiver.SequenceNumber = 5000;
newReceiver.Type = SPEventReceiverType.ItemDeleting;
Now the event has been deployed. Output
When I tried to delete the item
I got the below error message;Conclusion
I have shown how to handle item deleting event. Whenever any item will get deleted user will get error message. Thanks for reading.