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Get selected value from asp SharePoint DropDownList of custom class type

I am writing a SharePoint app. There I have page with drop down list. I have
a handler for SelectedIndexChanged. I want to get the selected value but as CustomObject and the only option I see is string. I tried SelectedValue and it is still string.
That's how I set the list:
protected void Page_Load(object sender, EventArgs e)
{
List<CustomObject> customList = //retrieving data
myDropDownList.DataSource = customList.Select(x => new { x.Name, Value = x});
myDropDownList.DataTextField = "Name";
myDropDownList.DataValueField = "Value";
myDropDownList.DataBind();
}
And that's one of the ways I tried:
protected void myDropDownList_SelectedIndexChanged(object sender, EventArgs e)
{
var index = groupingDropDownList.SelectedIndex;
CustomObject obj = (CustomObject)myDropDownList.Items[index].Value;
obj.DoSomething();
}
Is it even possible? Or do I have to have somewhere Dictionary with with objects?

You will want to leverage the html5 data attributes that you can then place onto the dropdown options. Here is an example of what you could do with your data.
// add Agencies' addresses as HTML5 data-attributes.
var agencies = agencyNames.ToList();
for (int i = 0; i < requesting_agency.Items.Count - 1; i++) {
requesting_agency.Items[i + 1].Attributes.Add("data-address",
agencies[i].address);
servicing_agency.Items[i + 1].Attributes.Add("data-address",
agencies[i].address);
}
Then when processing the information you could do something like so.
var index = groupingDropDownList.SelectedIndex;
var selectedText = myDropDownList.Items[index].SelectedValue;
var selectedValue = myDropDownList.Items[index].Attributes["attribute"];
// put into obj
// do something with object
Let me know if you have any questions.

You 're binding a object (x => new { x.Name, Value = x}) to dropdown value, you should bind actual value to it.
Test demo:
public class CustomObject
{
public int ID { get; set; }
public string Name { get; set; }
public CustomObject(int _ID,string _Name)
{
this.ID = _ID;
this.Name = _Name;
}
}
public partial class WebForm1 : System.Web.UI.Page
{
protected void Page_Load(object sender, EventArgs e)
{
List<CustomObject> customList = new List<CustomObject>();
customList.Add(new CustomObject(1,"test1"));
customList.Add(new CustomObject(2,"test2"));
myDropDownList.DataSource = customList.Select(x => new { x.Name, Value = x.ID });
myDropDownList.DataTextField = "Name";
myDropDownList.DataValueField = "Value";
myDropDownList.DataBind();
}
}

How to insert/update master-detail in Entity Framework?

I'm trying to make a master-detail Web Form working with Entity Framework and performing insert and update on the same page. I'm new at EF, so I must be making a lot of mistakes here. Can you help me pointing me what's the best practices to perform insert/update on EF? What am I doing wrong here?
In this code, the "New" mode works well, but the "Edit" mode gets this error: "An entity object cannot be referenced by multiple instances of IEntityChangeTracker".
OrdersEntities ordersEntities = new OrdersEntities();
private Order myOrder
{
get { return (Order)Session["myOrder"]; }
set { Session["myOrder"] = value; }
}
public DataTable dtOrderDetails
{
get { return (DataTable)ViewState["dtOrderDetails"]; }
set { ViewState["dtOrderDetails"] = value; }
}
private string Mode
{
get { return (string)ViewState["mode"]; }
set { ViewState["_modo"] = value; }
}
private void btnSaveOrder_Click(object sender, EventArgs e)
{
if (dtOrderDetails.Rows.Count > 0)
{
using (ordersEntities)
{
using (var contextTransaction = ordersEntities.Database.BeginTransaction())
{
try
{
if (Mode == "New")
{
Order newOrder = new Order();
OrderDetails newOrderDetails;
int maxOrderNumber = ordersEntities.Order.Select(o => o.OrderNumber).DefaultIfEmpty(0).Max();
maxOrderNumber++;
newOrder.OrderNumber = maxOrderNumber;
newOrder.Date = DateTime.ParseExact(txtOrderDate.Text, "dd/MM/yyyy", CultureInfo.InvariantCulture);
newOrder.CustomerID = Convert.ToInt32(ddlCustomer.SelectedValue);
newOrder.Status = 1;
ordersEntities.Orders.Add(newOrder);
foreach (DataRow dt in dtOrderDetails.Rows)
{
newOrderDetails = new OrderDetails();
newOrderDetails.OrderNumer = maxOrderNumber;
newOrderDetails.ProductId = Convert.ToInt32(dt["ProductId"]);
newOrderDetails.Quantity = Convert.ToInt32(dt["Quantity"]);
ordersEntities.OrderDetails.Add(newOrderDetails);
}
ordersEntities.SaveChanges();
contextTransaction.Commit();
myOrder = newOrder;
}
if (Mode == "Edit")
{
Order editedOrder = myOrder;
OrderDetails editedOrderDetails;
editedOrder.Date = DateTime.ParseExact(txtOrderDate.Text, "dd/MM/yyyy", CultureInfo.InvariantCulture);
editedOrder.CustomerID = Convert.ToInt32(ddlCustomer.SelectedValue);
ordersEntities.Order.Attach(editedOrder);
ordersEntities.Entry(editedOrder).State = System.Data.Entity.EntityState.Modified;
editedOrder.OrderDetails.Clear();
foreach (DataRow dt in dtOrderDetails.Rows)
{
editedOrderDetails = new OrderDetails();
editedOrderDetails.OrderNumer = editedOrder.OrderNumber;
editedOrderDetails.ProductId = Convert.ToInt32(dt["ProductId"]);
editedOrderDetails.Quantity = Convert.ToInt32(dt["Quantity"]);
ordersEntities.OrderDetails.Add(editedOrderDetails);
}
ordersEntities.SaveChanges();
contextTransaction.Commit();
}
}
catch (Exception ex)
{
contextTransaction.Rollback();
}
}
}
}
}

Here is how you should approach it.
It would be best if you abstract the DbContext away, with this simple interface:
public interface IDataRepository : IDisposable
{
IDbSet<Order> Orders { get; set; }
void Save();
}
Of course, your implementation of IDataRepository is based on EntityFramework. Note that you will need to have a dataRepositoryConnection connection string in your web.config file:
public class EfDataRepository : DbContext, IDataRepository
{
public EfDataRepository() : base("dataRepositoryConnection")
{
}
public IDbSet<Order> Orders { get; set; }
public void Save()
{
this.SaveChanges();
}
}
In my experience, you also need a 'factory', which gives you a new instance of the data repository. This allows you to be the 'owner' of the instance, and you can safely dispose it. Note that the interaction with the DataContext should be minimal - you do your Unity of Work and get rid of it. Don't reuse! You will see it as an example below.
public class DataRepositoryFactory<T> where T : IDataRepository
{
private Type dataRepositoryImplementationType;
public DataRepositoryFactory(T dataRepositoryImplementation)
{
if (dataRepositoryImplementation == null)
{
throw new ArgumentException("dataRepositoryImplementation");
}
this.dataRepositoryImplementationType = dataRepositoryImplementation.GetType();
}
public T Create()
{
return (T)Activator.CreateInstance(this.dataRepositoryImplementationType);
}
}
In your controller (if it were MVC app), or Page backend (forms), it would be best if you use Microsoft Unity to get an instance of DataRepositoryFactory. For now, a manual construction would suffice too.
IDataRepository dataRepository = new EfDataRepository();
var dataRepositoryFactory = new DataRepositoryFactory<IDataRepository>(dataRepository);
Also, you don't need all this Transaction/Commit stuff you have put. It should be transparent for you. EF supports it implicitly, you don't have to be explicit about it.
// See, now you are the 'owner' of the dataRepository
using (var dataRepository = this.dataRepositoryFactory.Create())
{
if (Mode == "New")
{
Order newOrder = new Order();
// This doesn't make sense. Either generate a random order number (e.g. a Guid), or just use the Order.Id as an order number, although I don't recommend it.
int maxOrderNumber = dataRepository.Orders.Select(o => o.OrderNumber).DefaultIfEmpty(0).Max();
maxOrderNumber++;
newOrder.OrderNumber = maxOrderNumber;
newOrder.Date = DateTime.ParseExact(txtOrderDate.Text, "dd/MM/yyyy", CultureInfo.InvariantCulture);
newOrder.CustomerID = Convert.ToInt32(ddlCustomer.SelectedValue);
newOrder.Status = 1;
dataRepository.Orders.Add(newOrder);
foreach (DataRow dt in dtOrderDetails.Rows)
{
OrderDetails newOrderDetails = new OrderDetails();
newOrderDetails.OrderNumer = maxOrderNumber;
newOrderDetails.ProductId = Convert.ToInt32(dt["ProductId"]);
newOrderDetails.Quantity = Convert.ToInt32(dt["Quantity"]);
newOrder.OrderDetails.Add(newOrderDetails);
}
myOrder = newOrder;
}
if (Mode == "Edit")
{
Order editedOrder = dataRepository.Orders.FirstOrDefault(o => o.Id == myOrder.Id);
editedOrder.Date = DateTime.ParseExact(txtOrderDate.Text, "dd/MM/yyyy", CultureInfo.InvariantCulture);
editedOrder.CustomerID = Convert.ToInt32(ddlCustomer.SelectedValue);
editedOrder.OrderDetails.Clear();
foreach (DataRow dt in dtOrderDetails.Rows)
{
OrderDetails editedOrderDetails = new OrderDetails();
editedOrderDetails.OrderNumer = editedOrder.OrderNumber;
editedOrderDetails.ProductId = Convert.ToInt32(dt["ProductId"]);
editedOrderDetails.Quantity = Convert.ToInt32(dt["Quantity"]);
editedOrder.OrderDetails.Add(editedOrderDetails);
}
}
dataRepository.Save();
}
Also, I am pretty sure you have setup the relation between Order and OrderDetails classes incorrectly, in your EF code-first approach.
This is just wrong:
OrderDetails newOrderDetails = new OrderDetails();
newOrderDetails.OrderNumer = maxOrderNumber;
If you post them here, I can fix them for you.

C# ComboBox List<object> ==> Show always the same object.name (multiple time)

I just want my ComboBox to show me the
FullName of objects in List(Curator),
but it show me the same "object.FullName" multiple times :-(
-
Basically, it work cause it show me the FullName of ONE of the Curator,
and the good amount of times,
but it show me the same ONE !
public partial class SGIArt : Form
{
public static Gallery gal = new Gallery(); // from a dll i made
List<Curator> curList = new List<Curator>();
public SGIArt()
{
InitializeComponent();
comboCur.DataSource = curList;
comboCur.ValueMember = null;
comboCur.DisplayMember = "FullName";
UpdateCurList();
}
public void UpdateCurList()
{
curList.Clear();
foreach (Curator cur in gal.GetCurList())
// from the same dll : Curators curatorsList = new Curators();
{
curList.Add(cur);
}
}
private void comboCur_SelectedIndexChanged(object sender, EventArgs e)
{
if (comboCur.SelectedValue != null)
{
//show info in textBox (that work fine)
}
}
}
Curator class :
public class Curator : Person
{
private int id;
private double commission;
const double commRate = 0.25;
private int assignedArtists = 0;
public int CuratorID
{
get
{
return id;
}
set
{
id = value;
}
}
...
public Curator()
{
}
public Curator(string First, string Last, int curID)
: base(First, Last) // from : public abstract class Person
{
id = curID;
commission = 0;
assignedArtists = 0;
}

Edit: You might be looking for this answer.
I do not see the FullName member in your code snippet. I think you are looking for something like this:
List<Curator> curList = new List<Curator>();
public SGIArt()
{
InitializeComponent();
comboCur.DataSource = datasource;
comboCur.ValueMember = null;
comboCur.DisplayMember = "FullName";
UpdateCurList();
}
List<string> datasource()
{
List<string> datasource = new List<string>();
foreach(Curator curator in curList)
{
datasource.Add(curator.FullName)//this assume FullName is an accesible member of the Curator class and is a string.
}
return datasource;
}

The comboBox shows you object.FullName, because this is what you are telling it. The curList is empty at the time when you bind it.
You can update your list before using it:
public SGIArt()
{
InitializeComponent();
UpdateCurList();
comboCur.DataSource = curList;
comboCur.ValueMember = null;
comboCur.DisplayMember = "FullName";
}

How can I share variables between Web forms?

I am developing a web application on C# .Net and I need to pass variables from form to another form. For example, in the first form I have person class as following;
public class Person
{
private string _Name;
private string _Surname;
private string _DateOfBirth;
private string _Gender;
private string _Symptoms;
public Person()
{
Name = "Not available";
Surname = "Not available";
DateOfBirth = "Not available";
Gender = "Not available";
Symptoms = "Not available";
}
public string Name
{
get { return _Name; }
set { _Name = value; }
}
public string Surname
{
get { return _Surname; }
set { _Surname = value; }
}
public string DateOfBirth
{
get { return _DateOfBirth; }
set { _DateOfBirth = value; }
}
public string Gender
{
get { return _Gender; }
set { _Gender = value; }
}
public string Symptoms
{
get { return _Symptoms; }
set { _Symptoms = value; }
}
}
Then I assign values;
protected void Page_Load(object sender, EventArgs e)
{
Person MyPerson = new Person();
MyPerson.Name = txtName.Text;
MyPerson.Surname = txtSurname.Text;
MyPerson.DateOfBirth = txtBirth.Text;
MyPerson.Gender = listGender.Text;
MyPerson.Symptoms = checked(listSymptoms.Text);
}
So, how can I use these values into another form?

consider Another_form is a new form's class that contain a method should accept an object(person class)... for example
public void foo(Person obj)
{ ///your code }
that's it... then you have to pass variable from another form like
protected void Page_Load(object sender, EventArgs e)
{
Person MyPerson = new Person();
MyPerson.Name = txtName.Text;
MyPerson.Surname = txtSurname.Text;
MyPerson.DateOfBirth = txtBirth.Text;
MyPerson.Gender = listGender.Text;
MyPerson.Symptoms = checked(listSymptoms.Text);
another_form f=new another_form();
f.foo(MyPersion)
}

You could make your form produce a Person instance instead:
// within your form class, whatever it is
public Person CreatePerson()
{
Person MyPerson = new Person();
MyPerson.Name = txtName.Text;
MyPerson.Surname = txtSurname.Text;
MyPerson.DateOfBirth = txtBirth.Text;
MyPerson.Gender = listGender.Text;
MyPerson.Symptoms = checked(listSymptoms.Text);
return MyPerson;
}
Then, from anywhere in your code, call your form instance's CreatePerson method:
var personFromUI = yourFormInstance.CreatePerson();
That is one way to do it.
You could also expose the person as a property of your form, or pass a Person instance throughout your application objects, be it forms, controls, controllers, etc... while this goes beyond the scope of your question, this would be the preferred way because it keeps your UI code and your business code separated.
I'd advise that you look into separation of concerns. You may learn a trick or two there about proper application design.

Are you saying that you have populated a person object and then on another form you'd like to reference the same instance of that person object? Probably the simplest way would be to store the object in Session and then retrieve it on the second form.
protected void Page_Load(object sender, EventArgs e)
{
Person MyPerson = new Person();
MyPerson.Name = txtName.Text;
MyPerson.Surname = txtSurname.Text;
MyPerson.DateOfBirth = txtBirth.Text;
MyPerson.Gender = listGender.Text;
MyPerson.Symptoms = checked(listSymptoms.Text);
Session["CurrentPerson"] = MyPerson;
}
Personally, I don't normally use session this way and instead build that type of workflow into my apps persistence layer (e.g. Sql Server, Redis).

Adding new Item to CSLA EF4 pattern

I'm adding a new item to my CSLA BusinessList. But I can only add it with a 0 primary key because my items which I add is always null. And if I try: "Item temp= new item{...}" is this item not child of the list.
I'll post my Add function first and then some dataportals.
public void ExecuteNew(object obj)
{
if (Model != null)
{
Temp = Model.AddNew();
//Temp.FarbauswahlNr = 123;
//Temp.Kurztext = this.Kurztext;
//Temp.Ressource = this.Ressource;
//Temp.Vari1 = this.Vari1;
Model = Model.Save();
}
}
Now some DataPortals from my Business class and BusinessList class
protected override void DataPortal_Update()
{
using (var ctx = Csla.Data.ObjectContextManager<Datenbank.TestDBEntities>.GetManager(Business.EntitiesDatabase.Name))
{
Child_Update();
}
}
protected override void Child_Create()
{
base.DataPortal_Create();
BusinessRules.CheckRules();
}
private void Child_Insert()
{
using (var ctx = Csla.Data.ObjectContextManager<TestDBEntities>.GetManager(EntitiesDatabase.Name))
{
try
{
var data = new Datenbank.Farbe();
data.Kurztext = ReadProperty<string>(KurztextProperty);
data.Ressource = ReadProperty<string>(RessourceProperty);
data.Var1 = ReadProperty<bool>(Vari1Property);
data.Vari2 = ReadProperty<string>(Vari2Property);
ctx.ObjectContext.Farben.AddObject(data);
ctx.ObjectContext.SaveChanges();
}
catch (Exception e)
{
MessageBox.Show(e.ToString());
}
}
}
Possible Errors :
NullReferebceException was unhadeld ( because temp is always null )

The Problem was: CSLA 4.5 has got a bug wich let your UI Freeze after the Save Command. Now im using CSLA 4.1 and it works just fine.