Object model to change item-level permission for a blog posts list

Question:

By default, blog posts in a blog site can be deleted or edited by anyone. How can I, using object model, restrict such that only owners can edit/delete. I would also like to do the same for comments list.

Currently, we can do that manually by going into "List Settings > Advanced Settings" and changing the item-level permissions. I would like to do the same thing but using object model so that I can automate this process. What is the API that I can use?

 

Answer:

Finally, I was able to get them working:

The way you get the reference to SPList object makes a difference.

If you have "Posts" list and want to set the writesecurity.

Below code does NOT work
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bl.Lists["Posts"].WriteSecurity = 2;
bl.Lists["Posts"].Update();
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However, this code works:
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SPList postsList = bl.Lists["Posts"];
postsList.WriteSecurity = 2;
postsList.Update();
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More information: http://msdn.microsoft.com/en-us/library/microsoft.sharepoint.splist.writesecurity.aspx

Similarly, there is ReadSecurity.

 

SPList.WriteSecurity Property:

Type: System.Int32

A 32-bit integer that specifies the Write security setting. Possible values include the following:

• 1 — All users can modify all items.

• 2 — Users can modify only items that they create.

• 4 — Users cannot modify any list item.