Monday, April 1, 2013

Creating Event Recievers within Visual Studio 2010

Event receivers can be broadly seen as of two types:

Asynchronous (triggered before finishing of previous event)
          ItemAdding, ItemUpdating
Synchronous (triggered after finishing the previous event)
          ItemAdded, ItemUpdated

Follow Steps to create an event receiver with Visual Studio 2010 and SharePoint 2010 :
  • Open up Visual Studio 2010 with administrator privileges
  • Click File > New > Project
  • Under Installed templates, click SharePoint and then select Event Receiver (C# in my case). Enter the name, storage location and Solution name in the text box provided and click on OK.
    • It will then ask you to specify the site and trust level or scope of your solution. If you want to deploy it across your farm so that all web applications can make use of it, you should select Deploy as Farm Solution. However, with event receivers, it is not usual so we will select Deploy as Sandboxed solution, which means it will only be accessible to the sites where we activate this feature.
    • Now it will ask you to select the type of Event Receiver you would like to create. In our case it would be List Item Events. Then select what item should be the event source, here we will select Document Library as we want to create an item in document library and want our event receiver logic to run after that. You may want to select Picture library or a list here or as per your business scenario.

    • Now, check the events you would want to code for within your receiver. For the sake of example, I will check An Item was Added which means it will automatically create a method stub for me with ItemAdded method. Now click on Finish.

    Our development IDE is ready to use now and you can see the method stub for ItemAdded being created already.

    Copy and Paste the code below to your solution.
    using (SPWeb web = properties.OpenWeb())
        //Name is a metadata column within my document library
        //Checking if the Name field is equal to Test
        if (properties.ListItem["Name"] == "Test") 
        {//If it is
            // Populating the Title field with some value
            properties.ListItem["Title"] = "Event handler works"; 
            // Updating the ListItem to incorporate the change. 
            // Necessary step, without this  the changes are not pushed to ListItem
    Some more useful methods which can be used are
    //Name of the Document Library
    string DocLibraryName = properties.ListTitle.ToString();
    //Getting the Item ID
    int ItemID = properties.ListItem.ID;
    //Collection of Role Assignments - required for controlling permission to the Item
    SPRoleAssignmentCollection roleAssignment = properties.ListItem.RoleAssignments;

    Build the solution and deploy it. Go to your SharePoint site and activate it(if not already activated) and create any document library and create an item with Name as Test and see your event receiver in action.

    This event receiver will fire on all the document libraries within your site where you have activated the feature, if this is not the intended behaviour, use
    if(properties.ListTitle.ToString() == "DocumentLibraryName")
    And write all your logic within your IF block.

    For any queries please feel free to email me. If this post helped you, please share it and benefit more and more fellow SharePoint developers

    1 comment:

    Subhash Degala said...

    this is really good anand...