Set Item Permissions

Question

Folders work:

I now know how to set the permissions of a folder in a library:

public void ChangeItemPermissions()
{
    _SharePoint.ClientContext _ClientContext = new _SharePoint.ClientContext("https://sharepoint.oshirowanen.com/sites/oshirodev/");
    _ClientContext.Credentials = new NetworkCredential("user", "pass", "oshirowanen.com");

    _SharePoint.Principal user = _ClientContext.Web.EnsureUser(@"oshirowanen\tom");

    var _List = _ClientContext.Web.Lists.GetByTitle("Library1");
    var _Item = _List.LoadItemByUrl("/sites/oshirodev/Library1/Folder1");
    var roleDefinition = _ClientContext.Site.RootWeb.RoleDefinitions.GetByType(_SharePoint.RoleType.Reader);
    var roleBindings = new _SharePoint.RoleDefinitionBindingCollection(_ClientContext) { roleDefinition };
    _Item.BreakRoleInheritance(false,true);
    _Item.RoleAssignments.Add(user, roleBindings);

    _ClientContext.ExecuteQuery();
}

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File attempt:

I've tried adding the file name to this line:

var _Item = _List.LoadItemByUrl("/sites/oshirodev/Library1/Folder1/File1.docx");

Notice the (/File1.docx) added to the end of the above line.

---

Error received:

But that just gives an error:

System.NullReferenceException was unhandled
  HResult=-2147467261
  Message=Object reference not set to an instance of an object.
  Source=ItemPermissions
  StackTrace:
       at ItemPermissions.Form1.ChangeItemPermissions() in c:\Users\Oshirowanen\Documents\Visual Studio 2013\Projects\ItemPermissions\ItemPermissions\Form1.cs:line 46
       at ItemPermissions.Form1.button1_Click(Object sender, EventArgs e) in c:\Users\Oshirowanen\Documents\Visual Studio 2013\Projects\ItemPermissions\ItemPermissions\Form1.cs:line 345
       at System.Windows.Forms.Control.OnClick(EventArgs e)
       at System.Windows.Forms.Button.OnClick(EventArgs e)
       at System.Windows.Forms.Button.OnMouseUp(MouseEventArgs mevent)
       at System.Windows.Forms.Control.WmMouseUp(Message& m, MouseButtons button, Int32 clicks)
       at System.Windows.Forms.Control.WndProc(Message& m)
       at System.Windows.Forms.ButtonBase.WndProc(Message& m)
       at System.Windows.Forms.Button.WndProc(Message& m)
       at System.Windows.Forms.Control.ControlNativeWindow.OnMessage(Message& m)
       at System.Windows.Forms.Control.ControlNativeWindow.WndProc(Message& m)
       at System.Windows.Forms.NativeWindow.DebuggableCallback(IntPtr hWnd, Int32 msg, IntPtr wparam, IntPtr lparam)
       at System.Windows.Forms.UnsafeNativeMethods.DispatchMessageW(MSG& msg)
       at System.Windows.Forms.Application.ComponentManager.System.Windows.Forms.UnsafeNativeMethods.IMsoComponentManager.FPushMessageLoop(IntPtr dwComponentID, Int32 reason, Int32 pvLoopData)
       at System.Windows.Forms.Application.ThreadContext.RunMessageLoopInner(Int32 reason, ApplicationContext context)
       at System.Windows.Forms.Application.ThreadContext.RunMessageLoop(Int32 reason, ApplicationContext context)
       at System.Windows.Forms.Application.Run(Form mainForm)
       at ItemPermissions.Program.Main() in c:\Users\Oshirowanen\Documents\Visual Studio 2013\Projects\ItemPermissions\ItemPermissions\Program.cs:line 18
       at System.AppDomain._nExecuteAssembly(RuntimeAssembly assembly, String[] args)
       at System.AppDomain.ExecuteAssembly(String assemblyFile, Evidence assemblySecurity, String[] args)
       at Microsoft.VisualStudio.HostingProcess.HostProc.RunUsersAssembly()
       at System.Threading.ThreadHelper.ThreadStart_Context(Object state)
       at System.Threading.ExecutionContext.RunInternal(ExecutionContext executionContext, ContextCallback callback, Object state, Boolean preserveSyncCtx)
       at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state, Boolean preserveSyncCtx)
       at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state)
       at System.Threading.ThreadHelper.ThreadStart()
  InnerException: 

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Relevant info:

This is a WinForm app running on a local machine, created with C#, using .NET 4.0. SharePoint version is 2010.

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The question:

How do I set the permissions for a specific file? As I already know how to set permissions for a specific folder.

Answer 1

I assume that andresm53 is right about you using the extension method he mentioned.

To get this method to work on files you need to query by FileLeafRef (file name) and make sure that you add FileLeafRef to query ViewFields.

/edit

One more very important thing, limit file query to exact folder with:

query.FolderServerRelativeUrl = System.IO.Path.GetDirectoryName(url).Replace("\\", "/");

Working code below:

void Main()
{
    ClientContext context = new ClientContext("https://sharepoint.oshirowanen.com/sites/oshirodev/");
    context.Credentials = new NetworkCredential("user", "pass", "oshirowanen.com");
    Principal user = context.Web.EnsureUser(@"oshirowanen\tom");
    ChangeItemPermissions(context, "/sites/oshirodev/Library1/Folder1/File1.docx", "Library1", user, RoleType.Reader);
}

// Define other methods and classes here
public static ListItem LoadItemByUrl(List list, string url)
{
    var context = list.Context;
    string ext = System.IO.Path.GetExtension(url);

    var query = new CamlQuery();
    if (string.IsNullOrEmpty(ext))
        query.ViewXml = String.Format("<View><RowLimit>1</RowLimit><Query><Where><Eq><FieldRef Name='FileRef'/><Value> Type='Url'>{0}</Value></Eq></Where></Query></View>", url);
    else
    {
        query.ViewXml = String.Format("<View><ViewFields><FieldRef Name=\"FileLeafRef\" /></ViewFields><Query><Where><Eq><FieldRef Name=\"FileLeafRef\" /><Value Type=\"Text\">{0}</Value></Eq></Where></Query><RowLimit>1</RowLimit></View>", System.IO.Path.GetFileName(url));
        query.FolderServerRelativeUrl = System.IO.Path.GetDirectoryName(url).Replace("\\", "/");
    }

    var items = list.GetItems(query);
    context.Load(items);
    context.ExecuteQuery();
    return items.Count > 0 ? items[0] : null;
}

public void ChangeItemPermissions(ClientContext context, string url, string listName, Principal user, RoleType type)
{    
    var list = context.Web.Lists.GetByTitle(listName);
    var item = LoadItemByUrl(list, url);
    var roleDefinition = context.Site.RootWeb.RoleDefinitions.GetByType(type);
    var roleBindings = new RoleDefinitionBindingCollection(context) { roleDefinition };
    item.BreakRoleInheritance(false, true);
    item.RoleAssignments.Add(user, roleBindings);
    context.ExecuteQuery();
}