I am using WPF MVVM model in my project using C#.Net.

I am trying to bind data from DB to multiselection combobox using MVVM.
Data binded in Itemsource collection. But not displayed in multiselection combobox.
Also based on the selection data should store in DB (SQL Server). We are using entity framework to save data.

Herewith I have attacehd my code. Please guide.

I have attached my XAML and ViewModel Code for your reference.

XAML Code:
==========


View Model:
==========


WindowElement winElement = GetWindowElement.GetElement(Collection.DashletFormName);
if (DataValidator.IsValid(winElement))
{

if (this.ViewMode == ViewModeType.Add)
{
bool doesExistAlready = DashletCollectionProperty.Count(x => x.DashletName == DashletName && x.DashletUserId == DashletUserId) > 0;
if (!doesExistAlready)
{
foreach (var Values in DashletCollectionProperty)
{

Values.UserName = UserCollection.Where(x => x.User_UserId == DashletUserId).Select(a => a.User_UserLoginId).Single(); //UserName;
Values.DashletName = DashletName;
Values.CreatedBy = LoginUserDetails.UserId;
Values.ModifiedUserId = LoginUserDetails.UserId;
Values.DateEntered = DateTime.Now;
Values.DateModified = DateTime.Now;
Values.DateModifiedUtc = DateTime.Now;
Values.DashletUserId = DashletUserId;
DashletAccess = false;
if (DashletAccess == false)
{
User_Dashlet_Type = User_Dashlet_Type + "0,";
DashletUserId = DashletUserId;
}
else
{
User_Dashlet_Type = User_Dashlet_Type + "1,";
DashletUserId = DashletUserId;
}
User_Dashlet_Type = User_Dashlet_Type.Remove(User_Dashlet_Type.Length - 1);
DashletUserId = DashletUserId.Remove(DashletUserId.Length - 1);

Values.User_Dashlet_Type = User_Dashlet_Type;

DashletCollection.Add(Values);
ResultInfo = VisaBirdRestMethods.VisaBirdSendData("CRUD_Operations_Dashlet_Rest/Insert" + DEModeEnum.Insert, Values, typeof(DEDashlet)) as DEErrorProvider;

if (ResultInfo.ErrorResult)
{
RestGetDashletList();
VisaBirdMessage.showMessage(Collection.DashletData + ContentResource["DetailsView_SaveSuccess_Validation"].ToString(), ContentResource["DetailsView_Information"].ToString(), DialogButton.Ok, 500);

}
else
{
VisaBirdMessage.showMessage(Collection.DashletData + ContentResource["DetailsView_SaveError_Validation"].ToString(), ContentResource["DetailsView_Information"].ToString(), DialogButton.Ok, 500);
}


Please advise.