Develop Reference

how to get text from combobox like item [1]

when i use this code "var z = comboBox.Items[1].ToString();" and then show z in "MessageBox" i get this message "DataMdellayer.custumer" but i want text of item 1
<ComboBox x:Name="comboBox" HorizontalAlignment="Left" Margin="57,63,0,0" VerticalAlignment="Top" Width="120"/>
and
comboBox.ItemsSource = database.Customers.ToList();
comboBox.DisplayMemberPath = "CustomerSay";
comboBox.SelectedValuePath = "CustomerID ";

You are using CustomerSay property of Customers to show the value.
When you say:
var z = comboBox.Items[1].ToString();
You are converting a Costumer to string
But, considering that you want that costumer's CostumerSay property, you have to look for it.
So you must cast your ComboBoxItem to Costumer
(Customer)comboBox.Items[1]
And then look for the property
var z = ((Customer)comboBox.Items[1]).CustomerSay

1- You can cast your item to the data source object (customer) as #Marko said.
2- Use MVVM and bind your combobox to a ViewModel property. WPF has strong binding system to implement MVVM.
3- You can override ToString method of Customer class:
public class Customer
{
public override string ToString()
{
return CustomerSay;
}
}
I prefer the second solution, but if you don't want to use MVVM pattern #Marko's solution is better.

The index of item one starts at zero in c# so change your code like below to get the item one
var z = comboBox.Items[0].ToString();

Binding an observable collection attribute to a label in WPF

I have the following observable collection called SalesOrderCollection
private static ObservableCollection<SalesOrder> _salesOrderCollection = new ObservableCollection<SalesOrder>();
public static ObservableCollection<SalesOrder> SalesOrderCollection
{
get { return _salesOrderCollection; }
set
{
_salesOrderCollection = value;
}
}
I am assigning values like this:
SalesOrder order = new SalesOrder();
order.ItemSubTotal = 234;
order.TotalTaxes = 12;
order.TOTAL = 12345;
SalesOrderCollection.Add(order);
In the view, I am setting it like this to the label:
<Label Content="{Binding Path=TOTAL, UpdateSourceTrigger =PropertyChanged}"/>
However the label is empty. Any suggestions as to what I am doing wrong here ?

First of all, you are binding incorrectly - the label should not be bound to a specific item in a collection. Instead you should use a list control to show the contents of the ObesrvableCollection, then bind the selected item in the list control to a property on the viewmodel. Then the label should also be bound to the same property which contains the selected object.
If you insist on doing indexed binding to a specific item in the ObservableCollection then this syntax should do it for you:
<Label Content="{Binding Path=SalesOrderCollection[0].TOTAL}"/>
Here is an example.
Just another pointer: I'm not sure why you've made your SalesOrderCollection property static - this looks like the start of some potentially smelly code.

Gets value from combobox in wpf binding by entity framework

I bind my combobox from entityframework and when I try to get value from my combobox by selecting value it gives back text like this {NameOfCompany = Name } How can i get only the value Name?
Thats the code in xaml
<ComboBox SelectionChanged="ComboFirma_SelectionChanged" Name="ComboFirma" Margin="109,10,10,0" Height="28" VerticalAlignment="Top">
<ComboBox.ItemTemplate>
<DataTemplate>
<TextBlock Name="txbCombo" Text="{Binding NameOfCompany}"></TextBlock>
</DataTemplate>
</ComboBox.ItemTemplate>
And I bind it like this.
var query2 = from f in model.Firmas
select new
{
f.NameOfCompany
};
ComboFirma.ItemsSource = query2.ToList();
I tried something like this to gets the selected value but always i get an exception.
var str = (TextBox)ComboFirma.Template.FindName("txbCombo", ComboFirma);
lblCompanyNameShow.Content = str.SelectedText;

ComboBox.SelectedItem will be of a item type. So normally you would need to cast SelectedItem to type of item in your collection. Now, because, in your case it's anonymous type, it's more difficult I think easiest way to get NameOfCompany is to use dynamic
dynamic selectedItem = ComboFirma.SelectedItem;
var name = selectedItem.NameOfCompany;
or you can use SelectedValue/SelectedValuePath
<ComboBox Name="ComboFirma" ... SelectedValuePath="NameOfCompany">
and in code
var name = (string)ComboFirma.SelectedValue;

Try like this
TextBlock tb1 = (TextBlock)ComboFirma.SelectedItem;
lblCompanyNameShow.Content = str.SelectedText;

Set an item on a WPF Combobox when ItemSource is binded to an Enum

I am having trouble assigning the a combobox item by using an enum value that the combobox source is assigned to.
The XAML
<ComboBox HorizontalAlignment="Left"
x:Name="cmbName"
VerticalAlignment="Top"
Width="120" Margin="79,48,0,0">
<ComboBox.ItemsSource>
<CompositeCollection>
<ListBoxItem Content="Please Select"/>
<CollectionContainer Collection="{Binding Source={StaticResource Enum}}" />
</CompositeCollection>
</ComboBox.ItemsSource>
</ComboBox>
The C# that is trying to set the combobox to an item in the enum
// The problem, the assignment doesn't work.
cmbName.SelectedItem = Enum.value;
I can only set a item by using the combobox SelectedIndex
cmbName.SelectedIndex = 2;
But this is hardcoding the index so if the enum changes, so will the value.
So how can I set the combobox by the enum value?
Thanks

It's very hard to tell what your problem is because you haven't fully documented your scenario. As such, all that I can do is to show you how to do what you want. As I prefer to work with properties, I won't be using any Resources for this example, but I'm sure that you'll still be able to relate this solution to your problem.
So, first we have a test enum and some properties and some initialisation:
public enum TestEnum
{
None, One, Two, Three
}
private TestEnum enumInstance = TestEnum.None;
public TestEnum EnumInstance
{
get { return enumInstance; }
set { enumInstance = value; NotifyPropertyChanged("EnumInstance"); }
}
private ObservableCollection<TestEnum> enumCollection = new ObservableCollection<TestEnum>() { TestEnum.None, TestEnum.One, TestEnum.Two, TestEnum.Three };
public ObservableCollection<TestEnum> EnumCollection
{
get { return enumCollection; }
set { enumCollection = value; NotifyPropertyChanged("EnumCollection"); }
}
...
EnumCollection.Add(TestEnum.One);
EnumCollection.Add(TestEnum.Two);
EnumCollection.Add(TestEnum.Three);
EnumInstance = TestEnum.Three;
Then we have a ComboBox:
<ComboBox Name="ComboBox" ItemsSource="{Binding EnumCollection}"
SelectedItem="{Binding EnumInstance}" />
If you run the application, then at this point the selected ComboBoxItem should read Three. Because the ComboBox.SelectedItem is data bound to the EnumInstance property, setting...:
EnumInstance = TestEnum.Two;
... is roughly the same as:
ComboBox.SelectedItem = TestEnum.Two;
Both of these would select the Two value in the ComboBox. However, note this example:
EnumInstance = TestEnum.None;
Setting either the EnumInstance or the ComboBox.SelectedItem property to TestEnum.None would have no effect in the UI because there is no TestEnum.None value in the data bound collection.

I apologise that my answer was descriptive enough, however, the reason why I haven't set my enum as a property as Sheridan has described below is that I need an extra string value in my combo which you can see is "Please Select" and unfortunately, I cannot put this in the enum.
But Sheridan's method and logic is the way to go if you want to do this.
However, for my problem, I simply just used
ComboBox.SelectedValue = Enum.Value.ToString();
Thanks

ListView binding cast items to ListViewItem

I have a ListView bound to an instance of data
ObservalbeCollection<ActivityItem> ActivityItems
<ListView
x:Name="ActivityItemsList"
ItemsSource="{Binding ActivityItems}"
ItemTemplate="{StaticResource Herke80ItemTemplate}"
Header="{Binding DateFilterListBox.SelectedItem}" />
When I run a filter, I want to select the ListViewItem bound to the ActivityItem within the ListView, and change its visibility depending on the filter selected.
I was doing this by keeping another ObservableCollection instance, meaning the data instance was duplicated. I then removed or added items accordingly. This took up a lot of loading time. So I figured I'd try keep to one binding, and disable or enable the UI elements.
foreach (ActivityItem activityItem in ActivityItemsList.Items)
{
if (activityItem == null) continue;
var index = ActivityItemsList.Items.IndexOf(activityItem);
(ActivityItemsList.Items[index] as ListViewItem).Visibility = Visibility.Collapsed;
int startComparer = DateTime.Compare(activityItem.Start, selectedStartDate);
int endComparer = DateTime.Compare(selectedEndDate, activityItem.End);
if (OverdueToggleSwitch.IsOn)
{
(ActivityItemsList.Items[index] as ListViewItem).Visibility = Visibility.Visible;
}
else
{
if (startComparer >= 0 && endComparer >= 0)
{
(ActivityItemsList.Items[index] as ListViewItem).Visibility = Visibility.Visible;
}
}
}
ex is a NullReferenceException, due to the fact that the ListViewItem is not actually a ListViewItem but an ActivityItem.
What is an alternative or the correct way of doing this?

I think you have over complicated it. If you use Snoop you can see that when you bind a ListView to a collection via ItemSource it ends up populated with a collection of ListViewItems where each ListViewItem has two things.
a DataContext set to the data (e.g. ActivityItem)
a ContentPresenter filled with the controls defined in your DataTemplate
This means that in theory you can browse both collections
from x in listView.Items select x as ListViewItem
or
from x in listView.Items select x.DataContext as ActivityItem
However if you simply want a filtered list then can I suggest changing your binding,
<ListView
x:Name="ActivityItemsList"
ItemsSource="{Binding FilteredItems}"
and
public class MyViewModel :INotifyPropertyChanged
{
public IEnumerable<ActivityItem> AllItems {get;set;} //needs to NotifyPropertyChanged(FilteredItems)
public Func<ActivityItem, bool> Filter { get;set;} //needs to NotifyPropertyChanged(FilteredItems)
public IEnumerable<ActivityItem> FilteredItems { get { return from x in AllItems where Filter(x) select x; }}
}
If you are still struggling with performance issues then have a quick read through Bea Costa's series on TreeView performance part one, part two and part three. It might help you to get WPF doing all the hard work for you.