Re: WPF and MVVM pattern question - WPF Discussion Boards

Rolorob20-Feb-09 3:48

Rolorob

20-Feb-09 3:48

Thanks, I think this is exactly what I need.
This is what I have so far:

xmlns:src="clr-namespace:WpfLookup"

<Window.Resources>
    <src:OrderCustomerDataset x:Key="dsCustomer.Customer" />
</Window.Resources>

(added in the XAML file)

It gives no errors.

But what I really want to bind, is the table in the instance of my dataset, dsCustomer.Customer. I have a feeling though that x:Key is only the name for in the XAML referencing?

I added this

ItemsSource="{Binding Source={StaticResource dsCustomer.Customer}}"

as ItemsSource to the Customer. But it now only displays one entry with one photo and thats it, I feel we are getting closer though Sniff | :^)

I hope these questions don't bother you, you are a great help to me Thumbs Up | :thumbsup:

ABitSmart20-Feb-09 4:04

ABitSmart

20-Feb-09 4:04

Rolorob wrote:
x:Key is only the name for in the XAML referencing

Yes, your right

Rolorob wrote:
displays one entry

Is the ListView still bound to the DataRelation ? Is yes, put it back to where it was before Smile | :)

I suspect

IsSynchronizedWithCurrentItem="True"

. Try removing the top part of the view which you would not be using and just run the bottom DataGrid part of your code.

If things still don't work, now since you are using a Grid sort of view, you can use a DataTemplate for the ListView instead of the CollectionView.

Rolorob wrote:
questions don't bother you

Not at all

Rolorob wrote:
you are a great help to me

Thanks

Rolorob20-Feb-09 6:10

Rolorob

20-Feb-09 6:10

Nice :p

When I alter the top combobox so that it's just like the bottom.
So remove from C# code:

this.cbCustomer.ItemsSource = dsOrder.Customer;

And add

ItemsSource="{Binding Source={StaticResource Customer}, Path=.}"

It doesn't work anymore then.
When I look at this:

<Window.Resources>
        <src:OrderCustomerDataset x:Key="Customer" />
    </Window.Resources>

It doesn't really say to me that it is the right instance of the DataSet/DataTable to bind to, how should I refrace that so that it binds to dsOrder.Customer? I think that's the part that's missing Confused | :confused:

ABitSmart21-Feb-09 2:42

ABitSmart

21-Feb-09 2:42

Well, you need to design the stuff as I mentioned earlier. Why dont you have a Wrapper Object containing Orders and Customers. You bind your main Window to this wrapper. Then, bind the Orders Grid View to DataContext.Orders and the customer combobox to DataContext.Customers (where DataContext is the datacontext of the main Window which you can reference it in the nested objects using the word "DataContext").

The path you are taking might also work. I do not know what OrderCustomerDataset is ?? If it is an object having a list of Customers then,

ItemsSource="{Binding Source={StaticResource Customer}, Path=ListOfCustomers}"

Remember, you will also need to handle the display of the appropriate customer in the combobox based on the CustomerId of the Order. On changing the customer the customerid in the orders table also has to be updated. You can use a ValueConverter(or MultiValueConverter) to drive the SelectedValue of ComboBox based on parameters and handle the combobox selection change.

Hope that helps(or makes matters worse??) Smile | :)

WPF and MVVM pattern question

mavifirar21-Feb-09 10:43

mavifirar

21-Feb-09 10:43

Cool text.Fine.
I'm blog
gelinlik

babongita18-Feb-09 8:14

18-Feb-09 8:14

I am trying to follow Karl Shifflett or Josh Smith MVVM pattern but I don't fully comprehend how I can make this happen. And I am hoping that I can get some help here.

I have an Object_A with some attributes, and an ObservableCollection<object_a>. Then in the UI I have a "view" of the attributes of Object_A, with a list box below which has the ObservableCollection<object_a>. What I want to be able to do is to be able to edit the attributes of the selected item in the list box and I want to be able to add a new Object_A if the "Add" button is clicked. This is where I get confused, because it is technically not bound any longer to the object in the list box it is it's own object that needs to be inserted into the ObservableCollection<object_a>.

I have two separate views and two view-models, and the "Add" button on the Object_A view-model, raises an event and passes the new Object A to the View-Model for the collection of Object_A, and if I set a break point and look at the Collection View-Model's ObservableCollection<object_a> which the UI is bound to the ObservableCollection<object_a> shows that the count has changed, but the UI doesn't reflect this change, is like the UI doesn't get notified that the ObservableCollection<object_a> has changed and the List box should be updated.

What should I be doing to get the UI to "refresh" itself when a new Object_A is being inserted into the ObservableCollection<objecta>?

Pete O'Hanlon18-Feb-09 8:44

18-Feb-09 8:44

Well - if you add the object to the ObservableCollection, the UI will be updated for you automatically (assuming you've used the appropriate bindings). How have you set up the Mode on your listbox? That's possibly where you are having a problem - try setting it to OneWay.

"WPF has many lovers. It's a veritable porn star!" - Josh Smith

babongita18-Feb-09 8:59

18-Feb-09 8:59

I was thinking it could be something with me overriding the OnCollectionChanged, but when I took that completely out, it still didn't work so I was thinking that it was something else.

Pete O'Hanlon18-Feb-09 9:09

18-Feb-09 9:09

If I could see the markup, it will be easier to get an idea.

"WPF has many lovers. It's a veritable porn star!" - Josh Smith

babongita18-Feb-09 10:02

18-Feb-09 10:02

Here is the XAML

<listbox x:name="lstScreens" xmlns:x="#unknown"> IsSynchronizedWithCurrentItem="True"
Grid.Row="1"
ItemsSource="{Binding Path=ReportScreens}"
ItemTemplate="{DynamicResource ScreenTabScreen}"
Margin="10,0,10,10">
And I can email any/all of the code for these areas if you would like.

Pete O'Hanlon18-Feb-09 10:16

18-Feb-09 10:16

Sure - my email is pete dot ohanlon at gmail dot com.

"WPF has many lovers. It's a veritable porn star!" - Josh Smith

Pete O'Hanlon19-Feb-09 21:52

19-Feb-09 21:52

Hi - I'm still waiting for the code. If you want to zip your project up, I'll take a look at it later on. My email is in my earlier post.

"WPF has many lovers. It's a veritable porn star!" - Josh Smith

babongita20-Feb-09 2:42

20-Feb-09 2:42

Sorry, Pete I did send you the code on Wednesday I used pete.ohanlon@gmail.com. I resent the code again just now, it will come from zoey.babongita@gmail.com.

If you don't get it soon, please let me know, You should have two emails now, the first one being a few classes, and the second one being the entire solution. Pick your poison.

Thanks

Pete O'Hanlon20-Feb-09 3:35

20-Feb-09 3:35

I've got them now. It looks like the original mail was picked up by the spam filter (though I'm not sure why). I'll take a look at them when I get home tonight.

"WPF has many lovers. It's a veritable porn star!" - Josh Smith

WPF ListView Databound Drag/Drop Auto Scroll

snblackout18-Feb-09 4:25

snblackout

18-Feb-09 4:25

Hi there, I've been working with Bea's solution here for a while and finding it very helpful. Problem now I'm having is when I drag-n-drop items within or to another ListView control and I want to scroll up/down "during" the drag (moving an item from index 30 to index 1), it's not happening. I would have to drag to the top of the visual items in the ListView, manually scroll up, then drag again, eventually ending at the position I want. This isn't very user friendly.

Now I found the function (DragDropHelper.DropTarget_PreviewDragOver) that I would want to do the testing of which item is being dragged over, and I'm getting that.

<br />
    Dim pt As Point = e.GetPosition(DirectCast(Me.targetItemsControl, UIElement))<br />
<br />
    ' Perform the hit test against a given portion of the visual object tree.<br />
    Dim result As HitTestResult = VisualTreeHelper.HitTest(Me.targetItemsControl, pt)<br />

Now from there I can get the DependencyProperty of this visual hit

<br />
    Dim lvi As ListViewItem = TryCast(GetDependencyObjectFromVisualTree(TryCast(result.VisualHit, DependencyObject), GetType(ListViewItem)), ListViewItem)<br />

Which is of a ListViewItem. Now in the function DropTarget_PreviewDragOver I have the "DraggedItem" which is of type Picture in Bea's example, but that can change depending on the ObservableCollection you have bound to the ListView. Now, I want to drag the ListView up or down depending on where the mouse is on the control. I've attempted with the below un-finished non-working code

<br />
    If lvi IsNot Nothing Then<br />
        If pt.Y <= 25 Then<br />
            Dim lv As ListView = TryCast(targetItemsControl, ListView)<br />
            If lv IsNot Nothing Then<br />
                Dim index As Integer = lv.Items.IndexOf(lvi)<br />
                If index > 1 Then<br />
                    lv.ScrollIntoView(lv.Items(index - 1))<br />
                End If<br />
            End If<br />
        Else<br />
            If pt.Y >= Me.targetItemsControl.ActualHeight - 25 Then<br />
                Debug.Print("Scroll Down")<br />
            End If<br />
        End If<br />
    End If<br />

Can someone point me in the right direction to get this ItemsControl or ListView to scroll when dragging over the items??

Thanks!

WPF System.Security.Permissions.SecurityPermission winmm.dll

Member 216927318-Feb-09 0:01

Member 2169273

18-Feb-09 0:01

hi everybody!

I have a problem that I can't find a solution.
I made a project (vs2008 xp sp2) wpf browser aplication.
I need to use midi functions of winmm.dll but there is a problem with "System.Security.Permissions.SecurityPermission".
I made a simple project (code below) with a button where by pressing it the debug stops.

.....
using System.Runtime.InteropServices;

namespace WpfBrowserApplication1
{
public partial class Page1 : Page
{
[DllImport("winmm.dll")] public static extern int midiInGetNumDevs();
public Page1()
{
InitializeComponent();
}

private void button1_Click(object sender, RoutedEventArgs e)
{
int aa = midiInGetNumDevs();
}
}
}

What shall I do? Somebody can help me?

My final project is to realize a musical keyboard that should play music according to a partiture upon the web. (sorry for my english)

Many Thanks for your attention.

Re: WPF System.Security.Permissions.SecurityPermission winmm.dll [modified]

sivaddrahcir18-Feb-09 13:00

sivaddrahcir

18-Feb-09 13:00

Calling into native code probably isn't something that you can do in a WPF browser app since they normally run in a partial trust environment: WPF Partial Trust Security[^].

As far as your goal of a musical keyboard deployed to the web is concerned:

* look into the possibility of using Silverlight (Silverlight Audio and Video Overview[^]
* you could go with a regular WPF application and distribute it using ClickOnce (see what MediaElement can do for you here)

Blog:
http://windowsclientdevelopment.spaces.live.com
FAQs:
http://windowspresentationfoundation.wikispaces.com
http://windowsmobile.wikispaces.com
http://vsto.wikispaces.com

Create Role

VisualLive17-Feb-09 22:19

VisualLive

17-Feb-09 22:19

Hi ,
i'm trying to understand how create role and save them in the database so doing i can add or delete the role for each user when i need ...i explain better my idea.
I created a form authentication(username,password) in Wpf to access to the application now i wish create roles and save on the database(with Linq ToSql) so doing i will assign roles(to deny or access to use buttons,Forms,Delete,Add,Edit etc.etc.) to user's for use the application but i don't know how procede with code to create roles and save it on database.
Do you have any idea to clarify my purpose and procede to work out this feature?

Have a happy day.

Bye

Re: Create Role

VisualLive18-Feb-09 14:46

VisualLive

18-Feb-09 14:46

Sorry ,
maybe my question is not clear i fell confuse about that.... Smile | :)

If you have some link that can clarify my mind i'm happy for your support.

Have a nice day.

Bye

DataContract and ISerializable not friendly

devvvy17-Feb-09 21:02

devvvy

17-Feb-09 21:02

In order to make this message go away on WCF method invoke,

"cannot be ISerializable and have DataContractAttribute attribute"

I commented out "Serializable" and ISerializable

<br />
[DataContract()]<br />
	// [Serializable()]<br />
	[GenericObjectAttribute(ObjectClassifier = "Person")]<br />
	public class Person : IPerson // , ISerializable<br />
	{<br />
	...<br />
        }

Does this means all DataContract must NOT be ISerilizable?

Thanks!

dev

Re: DataContract and ISerializable not friendly

Pete O'Hanlon17-Feb-09 21:51

17-Feb-09 21:51

If you turn your DataContract into a NetDataContractSerializer, you can mark it as Serializable. However, the DataContract is serialized for you by WCF so you shouldn't need to manage this yourself.

"WPF has many lovers. It's a veritable porn star!" - Josh Smith

Re: DataContract and ISerializable not friendly

devvvy18-Feb-09 0:59

devvvy

18-Feb-09 0:59

got it thanks

dev

Re: DataContract and ISerializable not friendly

Pete O'Hanlon18-Feb-09 2:06

18-Feb-09 2:06

No problem. Big Grin | :-D

"WPF has many lovers. It's a veritable porn star!" - Josh Smith