WPF Discussion Boards

I wanna retrieve value from the hidden column in datagrid in silverlight 4

mdrizwan_115-Jan-12 18:35

15-Jan-12 18:35

Hello,

I m in a bit trouble can any one please help me?
I have added a DataGrid on a usercontrol page in silverlight 4.And bind it to an 'xyz' table. When i m updating the contents of the table , m passing the xyzId of selected row which is in hidden column. Now were the problem arises m unable to get the value , it returns empty string . Any help appreciated?

Regards

Re: I wanna retrieve value from the hidden column in datagrid in silverlight 4

Mycroft Holmes15-Jan-12 20:59

Mycroft Holmes

15-Jan-12 20:59

You should NOT be working with the visual control when manipulating the data. You should be working with the underlying collection you have bound to the visual control.

Never underestimate the power of human stupidity
RAH

Re: I wanna retrieve value from the hidden column in datagrid in silverlight 4

mdrizwan_115-Jan-12 22:03

mdrizwan_1

15-Jan-12 22:03

Hello Holmes,

Thanks for your reply. I have bounded the datagrid Itemsource with service result.
That's the problem. Can you provide an sample or link to know how to get this done?.

Regards

Re: I wanna retrieve value from the hidden column in datagrid in silverlight 4

mdrizwan_116-Jan-12 23:28

mdrizwan_1

16-Jan-12 23:28

Hello buddies,

Solved it this way:
clsXYZ _clsxyz= dgxyz.SelectedItem as clsXYZ;

Regards

Adding images to silverlight datagrid

sudheesh kumar s14-Jan-12 0:51

sudheesh kumar s

14-Jan-12 0:51

Hi,
I want to add an image column to my data grid which is bound to a list. I had tried few options but didn't worked. No error coming but image is not getting loaded. what is the solution.

Thanks

Re: Adding images to silverlight datagrid

AbhijeetB14-Jan-12 22:05

AbhijeetB

14-Jan-12 22:05

Use DataGridTemplateColumn --> CellTemplate --> Image.

If no image is loaded and with no error then it must be a binding issue.

Slilverlight with WCF

sudheesh kumar s14-Jan-12 0:36

sudheesh kumar s

14-Jan-12 0:36

Hi,
I am new to silverlight. I have a web service method which returns a list. When i call it in the xaml page it is something like
webservice.myTestMethod() so where the return value goes. since we cannot assign the output directly to a variable how can we capture it

Thanks in advance

Re: Slilverlight with WCF

Pete O'Hanlon14-Jan-12 0:51

Pete O'Hanlon

14-Jan-12 0:51

I assume this is a strongly typed list and you are trying to bind something from the xaml to it. If so, simply use an ObservableCollection to bind to, and fill it with the results of the web service call.

Forgive your enemies - it messes with their heads

"Mind bleach! Send me mind bleach!" - Nagy Vilmos

My blog | My articles | MoXAML PowerToys | Mole 2010 - debugging made easier - my favourite utility

Re: Slilverlight with WCF

sudheesh kumar s14-Jan-12 1:06

sudheesh kumar s

14-Jan-12 1:06

thanks for your reply can you pls explain with an eg. thanks

Re: Slilverlight with WCF

Pete O'Hanlon14-Jan-12 2:18

Pete O'Hanlon

14-Jan-12 2:18

XML

public ObservableCollection<MyClass> PropToBindTo { get; private set; }

private void FillData()
{
  var data = new MyWebService().GetData();
  foreach (var value in data)
    PropToBindTo.Add(value);
}

This is just an example, but if it isn't clear to you then you need to read up on the basics of Silvelight. I would suggest buying a decent book.

Forgive your enemies - it messes with their heads

"Mind bleach! Send me mind bleach!" - Nagy Vilmos

My blog | My articles | MoXAML PowerToys | Mole 2010 - debugging made easier - my favourite utility

Silverlight 5 DataGrid MouseLeftButtonDown Fails

Mycroft Holmes13-Jan-12 21:06

Mycroft Holmes

13-Jan-12 21:06

So playing with Silverlight 5 and I want to implement the doubleclick event on the datagrid, simple enough except the MouseLeftButtonDown does not fire.

If I use the MouseLeftButtonUp it fires but the e.ClickCount never seems to increment past the first click.

When testing against a TextBlock the event works perfectly - very irritating! Now I don't wish to template every cell in every DataGrid in the application so does anyone have any news on this issue.

Never underestimate the power of human stupidity
RAH

UserControl as a TabItem

Tom Delany12-Jan-12 5:15

Tom Delany

12-Jan-12 5:15

Can someone please point me in the right direction? I'm already mostly bald, and I am pulling out what little hair that I have left!

Originally I had some XAML that looked something like this in my main window (I've left parts out for brevity):

XML

<Grid>
    <Grid.RowDefinitions>
        <RowDefinition Height="40" />
        <RowDefinition Height="*" />
    </Grid.RowDefinitions>
    <TextBlock Text="TapeStream Management Console"
           FontSize="20" TextAlignment="Center" VerticalAlignment="Center"/>
    <TabControl Grid.Row="1">
    <TabItem Header="Catalog">
        <views:CatalogTab>
    </TabItem>
    <TabItem Header="Datasets">
    ... etc.
    </TabItem>
    ... etc.
</Grid>

Under each tab item I had a UserControl that displayed the actual information. The DataContext for each UserControl was set in the code behind. Things rendered pretty much the way I expected. (Yeah, I know this UI is not going to win any awards, but it is a start.)

I had some issues with this implementation (trying to get a chance to prompt for the user to save changes when they switch to a different tab), and Collin Jasnoch[^] was kind enough to suggest an alternative approach. [^]

I got it to somewhat work after what he was telling me finally penetrated my thick skull (with a little extra pounding from Pete O'Hanlon[^]). Smile | :)

The problem that I have now is that it is rendering all screwy. The MainWindow XAML looks more like this now:

XML

<Grid>
    <Grid.RowDefinitions>
        <RowDefinition Height="40" />
        <RowDefinition Height="*" />
    </Grid.RowDefinitions>
    <TextBlock Text="TapeStream Management Console"
           FontSize="20" TextAlignment="Center" VerticalAlignment="Center"/>
    <TabControl Grid.Row="1" ItemsSource="{Binding ViewModels}" SelectedItem="{Binding SelectedItem}"/>
</Grid>
...

I now have a MainWindowViewModel class that is set as the DataContext for the MainWindow. It contains an ObservableCollection of my various ViewModels as per Collin's suggestion. I have a ResourceDictionary set up with the DataTemplates for my ViewModels / UserControls as suggested by Collin and Pete:

XML

<ResourceDictionary xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
                    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
                    xmlns:views="clr-namespace:TapeStreamManagementConsole.View"
                    xmlns:vms="clr-namespace:TapeStreamManagementConsole.ViewModel">
    <DataTemplate DataType="{x:Type vms:CatalogViewModel}">
        <views:CatalogTab />
    </DataTemplate>
    <DataTemplate DataType="{x:Type vms:DataSetsViewModel}">
        <views:DataSetsView />
    </DataTemplate>
    <DataTemplate DataType="{x:Type vms:TapeImageFilesViewModel}">
        <views:TapeImageFilesView />
    </DataTemplate>
</ResourceDictionary>

1) I cannot figure out any way to get tab headers and make the TabControl look "normal".
2) My UserControls have a ListBox on the left-hand side that no longer has scroll bars. Confused | :confused:

I tried changing my DataTemplates to look like this:

XML

<DataTemplate DataType="{x:Type vms:CatalogViewModel}">
    <TabItem Header="Catalog" >
        <views:CatalogTab />
    </TabItem>
</DataTemplate>

When I do that, I end up with Tabs with headings, but no content! Help!

WE ARE DYSLEXIC OF BORG. Refutance is systile. Your a$$ will be laminated.

There are 10 kinds of people in the world: People who know binary and people who don't.

Re: UserControl as a TabItem

Tom Delany12-Jan-12 9:14

Tom Delany

12-Jan-12 9:14

OMG! You are the man! Big Grin | :-D

It works! Thank you, thank you, thank you! Thumbs Up | :thumbsup:

If you only had an idea how much time I have spent Googling around trying to figure this out, going up all kinds of blind alleys and dead ends... D'Oh! | :doh:

If I could vote you a 10, I would. I am in your debt.

WE ARE DYSLEXIC OF BORG. Refutance is systile. Your a$$ will be laminated.

There are 10 kinds of people in the world: People who know binary and people who don't.

Is IEnumerable<> a sufficent type for WPF binding?

Harry von Borstel12-Jan-12 3:16

Harry von Borstel

12-Jan-12 3:16

Hi,

using MVVM I'm looking for a general guideline that tells me what type I should use for properties in the viewmodel that are exposing lists.

I think, in general it is a good idea to keep the type as basic as possible (e.g. not ObjectSet<T> but IQueryable<T> or IEnumerable<T>) in order to hide implementation from the interface. Thus, I started using IEnumerable<T>. Unfortunately it turned out, that the WPF designer (VS 2010) doesn't like this very much. The editor popup of the Properties view doesn't show me the members of my record type T. It seems that the designer needs at least IQueryable<T>, ICollection<T> or T[].

Does anyone know a reason for this? I found no issues in using IEnumerable<T> at runtime, only at design time.

Thanks,

Harry

Re: Is IEnumerable a sufficent type for WPF binding?

Pete O'Hanlon12-Jan-12 3:24

Pete O'Hanlon

12-Jan-12 3:24

Unfortunately, the Cider designer isn't the greatest designer in the world. One thing though - if your types are going to need to update the UI based off changes, you must make sure that they implement INotifyCollectionChanged.

Forgive your enemies - it messes with their heads

"Mind bleach! Send me mind bleach!" - Nagy Vilmos

My blog | My articles | MoXAML PowerToys | Mole 2010 - debugging made easier - my favourite utility

Re: Is IEnumerable a sufficent type for WPF binding?

Harry von Borstel12-Jan-12 3:59

Harry von Borstel

12-Jan-12 3:59

- Unfortunately, the Cider designer isn't the greatest designer in the world.
But should not VS be the greatest IDE and should not WPF be its greatest UI system? Sniff | :^)

- make sure that they implement INotifyCollectionChanged
That was the reason for me to put my records in a new container.

Thanks, Harry

Re: Is IEnumerable a sufficent type for WPF binding?

Pete O'Hanlon12-Jan-12 4:32

Pete O'Hanlon

12-Jan-12 4:32

I was aiming for something that didn't say "VS Cider sucks".

Forgive your enemies - it messes with their heads

"Mind bleach! Send me mind bleach!" - Nagy Vilmos

My blog | My articles | MoXAML PowerToys | Mole 2010 - debugging made easier - my favourite utility

Re: Is IEnumerable a sufficent type for WPF binding?

Abhinav S12-Jan-12 4:02

Abhinav S

12-Jan-12 4:02

ObservableCollection is a minimal requirement for collection binding.

Re: Is IEnumerable a sufficent type for WPF binding?

Pete O'Hanlon12-Jan-12 4:18

Pete O'Hanlon

12-Jan-12 4:18

Well, it's not really. SL and WPF don't require it for update notification, rather they rely on the internal interfaces that ObservableCollection uses.

Forgive your enemies - it messes with their heads

"Mind bleach! Send me mind bleach!" - Nagy Vilmos

My blog | My articles | MoXAML PowerToys | Mole 2010 - debugging made easier - my favourite utility

Re: Is IEnumerable a sufficent type for WPF binding?

Abhinav S12-Jan-12 17:55

Abhinav S

12-Jan-12 17:55

I did not mean he cannot use any other collection and ObservableCollection is the only collection that can be used.
My answer should have suggested that it could be prudent to use ObservableCollection as it already includes INotifyCollectionChanged implemented.

Re: Is IEnumerable a sufficent type for WPF binding?

Harry von Borstel12-Jan-12 6:18

Harry von Borstel

12-Jan-12 6:18

Coming back to my question, what do you think: Are there other drawbacks than bad designer support in using IEnumerable?

The background is the class AutoRefreshWrapper<T> in my article AutoRefresh Entity Framework Data Using SQL Server Service Broker[^]. Should I let it implement IQueryable or ICollection in order to make cider happy?

modified 12-Jan-12 13:00pm.

Re: Is IEnumerable a sufficent type for WPF binding?

Harry von Borstel12-Jan-12 9:28

Harry von Borstel

12-Jan-12 9:28

Thanks, Collin, for your comment Smile | :)

In addition, it seems that I've to implement IList too, in order to enable grid editing.

Re: Is IEnumerable a sufficent type for WPF binding?

Abhinav S12-Jan-12 18:00

Abhinav S

12-Jan-12 18:00

I agree totally and that is what I meant.
If you don't need notification support, any generic collection (IEnumerable or IList) could suffice.

However, I wanted to suggest to the OP that if he needs binding update notification, then ObservableCollection should be an option to consider. Should have clearly mentioned that in my first answer.

Re: Is IEnumerable a sufficent type for WPF binding?

Dean Oliver23-Jan-12 19:08

Dean Oliver

23-Jan-12 19:08

Try to avoid other collections and stick with observableCollection or a derived implementation of that. As Ilist is far slower in binding than an ObservableCollection.
http://msdn.microsoft.com/en-us/library/bb613546.aspx[^]

Quote:
Data binding the ItemsSource

Update time for 1 item (ms)

To a CLR List<t> object

1656ms

To an ObservableCollection<t>

20ms

Tooltip on DataGridTemplateColumn header [solved]

Ravi Bhavnani11-Jan-12 6:01

Ravi Bhavnani

11-Jan-12 6:01

I'm trying to display a tooltip on the column header of a DataGridTemplateColumn. The interwebs and StackOverflow's suggestions have been surprisingly unhelpful. A nudge in the right direction would be much appreciated. Basically what I want to do is replace this:

<data:DataGridTemplateColumn x:Key="EmployeeIdColumn"
                             Header="Employee ID"
                             Width="Auto" CanUserSort="True"
                             SortMemberPath="EmployeeId">

with this (obviously incorrect syntax, but hopefully the intent is clear):

<data:DataGridTemplateColumn x:Key="EmployeeIdColumn"
                             Header="Employee ID"
                             TooltipService.Tooltip="The employee's ID"   <-- Tooltip
                             Width="Auto" CanUserSort="True"
                             SortMemberPath="EmployeeId">

Thanks,

/ravi

My new year resolution: 2048 x 1536
Home | Articles | My .NET bits | Freeware
ravib(at)ravib(dot)com

modified 11-Jan-12 12:11pm.

Use Ctrl+Left/Right to switch messages, Ctrl+Up/Down to switch threads, Ctrl+Shift+Left/Right to switch pages.