Tuple as a Binding Parameter - WPF Discussion Boards

Grid Dynamic Column and Row in run time in WPF MVVM

sels198711-Sep-12 15:59

sels1987

11-Sep-12 15:59

Hi,

I am creating an application in WPF using MVVM pattern. My requirement is to use a grid which should support dynamic row creation and columns are not static , it will be vary always depends on the selection.

Please help to achieve it.

Thanks in advance,
Selvam S

Re: Grid Dynamic Column and Row in run time in WPF MVVM

Clifford Nelson12-Sep-12 13:39

Clifford Nelson

12-Sep-12 13:39

You should have not problem with creating a completely dynamic environment with WPF and a DataGrid. I have the following xaml:

<Window x:Class="DynamicGrid.MainWindow"
				xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
				xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
				xmlns:local="clr-namespace:DynamicGrid"
				Title="MainWindow"
				Height="350"
				Width="525">
	<Window.DataContext>
		<local:ViewModel />
	</Window.DataContext>
	<Grid>
		<DataGrid AutoGenerateColumns="True"
							ItemsSource="{Binding Children}"
							HorizontalAlignment="Stretch"
							Name="dataGrid1"
							VerticalAlignment="Stretch" />
	</Grid>
</Window>

with the following ViewModel:

class ViewModel
{
    public ViewModel()
    {
        var temp = new BindingList<Class1>();
        temp.Add(new Class1 {TypeA = "AAAA", TypeB = "BBBB"});
        temp.Add(new Class1 { TypeA = "CCCC", TypeB = "CCCC" });
        _children = temp;
    }
    private IEnumerable<object> _children;
    public IEnumerable<object> Children
    {
        get { return _children; }
        set { _children = value; }
    }
}

The grid is automatically created, and can add new rows. Just use what ojects you need. If you need something even more dynamic, then can bind to a class that inherits from DynamicObject

PopUp Window Open and close in WPF MVVM pattern

sels19878-Sep-12 21:53

sels1987

8-Sep-12 21:53

Hi,

I am developing a WPF application in MVVM pattern.

I got stuck in closing a popup window. I will explain how I started my application.

I created Main window, Login User Control and New User window.
In my main window , I used content control to load my login user control. On clicking the new user button in login screen, I initiated new user window and then I filled user registration details in new user window and then clicked OK. Now my new user window must get closed and stay with main window but it is not happening.

But I am not able to close the new user window through my button click.

Kindly help me in this situation and provide me a best approach to solve the issue.

Thanks in advance
Regards,
Selvam S

Re: PopUp Window Open and close in WPF MVVM pattern

Mycroft Holmes9-Sep-12 14:25

Mycroft Holmes

9-Sep-12 14:25

Personally I use code behind to handle the click event of the button and set the DialogResult. Any processing of the data is done in the VM and is called from the code behind.

Never underestimate the power of human stupidity
RAH

Re: PopUp Window Open and close in WPF MVVM pattern

Pete O'Hanlon10-Sep-12 5:03

Pete O'Hanlon

10-Sep-12 5:03

This[^] is a fairly common solution to this problem.

*pre-emptive celebratory nipple tassle jiggle* - Sean Ewington

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

CodeStash - Online Snippet Management | My blog | MoXAML PowerToys | Mole 2010 - debugging made easier

Re: PopUp Window Open and close in WPF MVVM pattern

Abhinav S10-Sep-12 16:14

Abhinav S

10-Sep-12 16:14

If you look at the Prism samples[^], you will find a good solution that you could use to implement a self-closing popup dialog.
Just handle the mouse click event on the shell and you can close any popups that are open on the shell.

Windows Phone Apps - XKCD | Calvin | SMBC | Dilbert | Speed Dial

Re: PopUp Window Open and close in WPF MVVM pattern

_Maxxx_29-Oct-12 17:30

_Maxxx_

29-Oct-12 17:30

When I looked at WPF and MVVM I solved this by creating a base UserControl that handled showing itself on a form - either modally or not.

The ViewModel then has the ability of telling the view to close itself

Personally I think it is a far simpler solution than any others I have come across

You can see it in action if you read my articles (link in signature)

MVVM# - See how I did MVVM my way
___________________________________________
Man, you're a god. - walterhevedeich 26/05/2011

.\\axxx
(That's an 'M')

Tuple as a Binding Parameter

Ahrimal6-Sep-12 22:11

Ahrimal

6-Sep-12 22:11

Hi there.

I have a control, that depending on its size and diferent parameters return me a value. Issue is that I need to do this in xalm and not in code, and do not know how to pass a tuple using xaml.

Now I have it by code:

Binding dataBinding = new Binding();
                dataBinding.Source = this.ZoomMemoryArea.MemoryAreaData;
                dataBinding.UpdateSourceTrigger = UpdateSourceTrigger.PropertyChanged;
                dataBinding.Path = new PropertyPath("Size");
                dataBinding.Converter = new BlockingRectangleMemorySizeConverter();
                dataBinding.ConverterParameter = new Tuple<Canvas, IMemoryAreaData>(this.zoomCanvas, this.MemoryArea.MemoryAreaData);
                dataBinding.Mode = BindingMode.OneWayToSource;
                this.zoomControl.SetBinding(Control.WidthProperty, dataBinding);

And the ???? is what I really do not know how to do.

XML

<pre lang="xml"><ContentControl.Width>
    <Binding Mode="OneWayToSource" UpdateSourceTrigger="PropertyChanged"  Converter="{StaticResource memorySizeConverter} ConverterParameter=???? Path="MemoryAreaData.Size" Source="ZoomMemoryArea">
                </Binding></pre>

As for multiBinding, I can't use it as this is a OneWayToSource binding so I would not get more than one value.

Any sugestion would be much apreciated.

Regards

Forgot to add the converter

Binding to an XML list of attributes

Jayme656-Sep-12 11:46

Jayme65

6-Sep-12 11:46

I have an XML file structured this way:

XML

<Emulators>
    <System>
        <Name>Name1</Name>
        <Kind name="lexplode"/>
        <Kind name="sexplode"/>
        <Kind name="dropbomb"/>
    </System>
</Emulators>

If I want to read, in XAML, from <Name> I know that I have to do:

<TextBox Text="{Binding XPath=Name, UpdateSourceTrigger=PropertyChanged}"/>

But what if I want to read all the values under <Kind>> ?
And which control could receive them, a textbox, a listbox, ..?

Thanks a lot!!

modified 7-Sep-12 2:43am.

Re: Binding to an XML list of attributes

Pete O'Hanlon6-Sep-12 22:24

Pete O'Hanlon

6-Sep-12 22:24

In order to get the attribute, you have to use a slightly different type of syntax. Rather than using XPath=name, you have to use XPath=@name. Now, that will only get you the value of the currently selected Kind item, so how do you actually get that item? Well, the answer is to use something like a ListBox to encapsulate the items.

XML

<ListBox ItemsSource="{Binding Source={MyEmulatorsList, XPath=//Kind}" ItemTemplate="{StaticResource KindItemsTemplate}" />

Note: In this sample, I'm assuming that you have used an XmlDataProvider called MyEmulatorsList to point to this XML. So, where is the actual display of the name item? Well, that's provided by the ItemTemplate, which looks like this:

XML

<DataTemplate x:Key="KindItemsTemplate">
  <TextBlock Text="{Binding XPath=@name}" />
</DataTemplate>

*pre-emptive celebratory nipple tassle jiggle* - Sean Ewington

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

CodeStash - Online Snippet Management | My blog | MoXAML PowerToys | Mole 2010 - debugging made easier

Re: Binding to an XML list of attributes

Jayme657-Sep-12 6:11

Jayme65

7-Sep-12 6:11

Thanks for your reply!!
I think that I'd better expose the whole code.

XML file:

XML

<Emulators>
    <System>
        <Gear>Name1</Gear>
        <Kind name="att1"/>
        <Kind name="att2"/>
        <Kind name="att3"/>
    </System>
</Emulators>

VB code:

Class MainWindow
    Dim data As XmlDataProvider = New XmlDataProvider()
    Private Sub MainWindow_Initialized(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Initialized
        data.Source = New Uri(Environment.GetFolderPath(Environment.SpecialFolder.ApplicationData) & "\myapplication\Systems.xml")
        data.XPath = "Emulators/System"
        Grid1.DataContext = data
    End Sub
End Class

XAML code:

XML

<Window x:Class="MainWindow"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:local="clr-namespace:WpfApplication1"         
    Title="MainWindow" Height="350" Width="525" Background="#FF4E4E64">
    <Grid Name="Grid1">
        <Grid.Resources>
            <DataTemplate x:Key="KindTemplate">
                <TextBlock Text="{Binding XPath=@name}" />
            </DataTemplate>
        </Grid.Resources>
        <TextBox Text="{Binding XPath=Gear, UpdateSourceTrigger=PropertyChanged}" Height="23" HorizontalAlignment="Left" Margin="197,230,0,0" Name="TextBox3" VerticalAlignment="Top" Width="220" />
        <ListBox ItemsSource="{Binding Source=data, XPath=//Kind}" ItemTemplate="{StaticResource KindTemplate}" Margin="261,51,12,149" />
        </Grid>
</Window>

It doesn't work, I get a

System.Windows.Data Error: 44 : BindingExpression with XPath cannot bind to non-XML object.; XPath='//Kind' BindingExpression:Path=; DataItem='String' (HashCode=2037252866); target element is 'ListBox' (Name=''); target property is 'ItemsSource' (type 'IEnumerable') data

modified 7-Sep-12 13:08pm.

Re: Binding to an XML list of attributes

Pete O'Hanlon7-Sep-12 6:52

Pete O'Hanlon

7-Sep-12 6:52

You are trying to bind to Emulators in your XPath, but your XML says Base.

*pre-emptive celebratory nipple tassle jiggle* - Sean Ewington

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

CodeStash - Online Snippet Management | My blog | MoXAML PowerToys | Mole 2010 - debugging made easier

Re: Binding to an XML list of attributes

Jayme657-Sep-12 7:10

Jayme65

7-Sep-12 7:10

You are trying to bind to Emulators in your XPath, but your XML says Base.

That's a typing mistake in my post (I've corrected it in my post)...but actually the XML file is correct..so the mistake doesn't come from here.

Re: Binding to an XML list of attributes

dbaseman7-Sep-12 21:06

dbaseman

7-Sep-12 21:06

I think I see what the problem is. In the ListBox XAML, you don't need the Source=data (that's incorrect syntax, and besides, you already set the DataContext from the code-behind, so it's not needed. Take that part out, and it should work:

XML

<ListBox ItemsSource="{Binding XPath=//Kind}" ItemTemplate="{StaticResource KindTemplate}" 
    Margin="261,51,12,149" />

Re: Binding to an XML list of attributes

Jayme658-Sep-12 0:32

Jayme65

8-Sep-12 0:32

Thank you very much!! For the first time I can see those data displayed!! Wink | ;-)

Just one think... of importance:
ALL the "Kind" attributes are displayed.
I've tried a "IsSynchronizedWithCurrentItem="True"" but it doesn't change anything.
Any idea on how to fix it, please?

The datatemplate for the combobox that displays the system's "Name":

XML

<DataTemplate x:Key="SystemTemplate">
  <Label Content="{Binding XPath=Gear}"/>
</DataTemplate>

The datatemplate for the ListBox that display the "Kind" name attributes (related to the selected "System"!!):

XML

<DataTemplate x:Key="KindTemplate">
  <TextBlock Text="{Binding XPath=@name}"/>
</DataTemplate>

The WPF controls:

XML

<ComboBox  Height="37" HorizontalAlignment="Left" Margin="12,262,0,0" Name="ComboBox1" VerticalAlignment="Top" Width="167"
  ItemsSource="{Binding}"
  ItemTemplate="{StaticResource SystemTemplate}"
  IsSynchronizedWithCurrentItem="True">
</ComboBox>

<ListBox ItemsSource="{Binding XPath=//Kind}" ItemTemplate="{StaticResource KindTemplate}" IsSynchronizedWithCurrentItem="True" Margin="425,35,12,149" />

modified 8-Sep-12 6:48am.

Re: Binding to an XML list of attributes

dbaseman8-Sep-12 10:08

dbaseman

8-Sep-12 10:08

You can select an item by using the XPath expression. Instead of XPath=//Kind, use XPath=//Kind[0], or XPath=//Kind[1], etc.

Re: Binding to an XML list of attributes

Jayme659-Sep-12 0:04

Jayme65

9-Sep-12 0:04

dbaseman,
Thanks again for taking time to help me!

If you consider my XML file

<Emulators>
    <System>
        <Gear>Name1</Gear>
        <Kind name="a1"/>
        <Kind name="a2"/>
        <Kind name="a3"/>
    </System>
    <System>
        <Gear>Name2</Gear>
        <Kind name="b1"/>
        <Kind name="b2"/>
        <Kind name="b3"/>
    </System>
</Emulators>

Using "XPath=//Kind[1]" will return: "a1, b1"
What I would like is "a1, a2, a3" being returned!!

How should I please proceed to achieve this (returning all "Kind" attributes of the currently selected "System"?
Thanks very much,

modified 9-Sep-12 6:20am.

Re: Binding to an XML list of attributes

dbaseman9-Sep-12 16:18

dbaseman

9-Sep-12 16:18

I'm not really an XPath expert, but my guess would be: //System[1]/Kind

How to implement a gallery like the built-in gallery in Windows Phone

small25-Sep-12 16:22

small2

5-Sep-12 16:22

I 'd like to creatre a gallery control just like the built-in gallery in Windows Phone 7. I put a listbox in the grid to show the thumail image, but it cost many memory. And crashed soon after I loaded more than 80 pics(640*480). Could anyone give me a help?

Re: How to implement a gallery like the built-in gallery in Windows Phone

small29-Sep-12 15:19

small2

9-Sep-12 15:19

Thanks for the reply!
I had added the item items to the listbox using databiding like this:

<ListBox.ItemTemplate>
  <DataTemplate>
    <Grid Margin="2" Tag="{Binding ThumID}" Tap="Grid_Tap">
      <Image x:Name="selTag" Width="32" Height="32" Source ="/Resources/Images/sel.png" Visibility="Collapsed" Tag="{Binding FilePath}" VerticalAlignment="Bottom" HorizontalAlignment="Right" Canvas.ZIndex="5"/>
     <Image Width="160" Height="120" x:Name="thumImage" Stretch="Uniform" CacheMode="BitmapCache" Source="{Binding ThumBitMap}" />
     <toolkit:ContextMenuService.ContextMenu>
       <toolkit:ContextMenu Width="200"orderThickness="5" Opened="contentMenu_Opened" Closed="contentMenu_Closed" IsZoomEnabled="False" Background="#c8b3d9ff" BorderBrush="LightGray">
        <toolkit:MenuItem x:Name="cm_Del" Header="Delete" Click="cm_Del_Click" Tag="{Binding}"/>
        <toolkit:MenuItem x:Name="cm_Edit" Header="Edit" Click="cm_Edit_Click" Tag="{Binding}"/>
        <toolkit:MenuItem x:Name="cm_Share" Header="Share" Click="cm_Share_Click" Tag="{Binding}"/>
       </toolkit:ContextMenu>
     </toolkit:ContextMenuService.ContextMenu>
    </Grid>
 </DataTemplate>
</ListBox.ItemTemplate>

Set background of TreeViewItem within HierarchicalDataTemplate with converter

toengi19824-Sep-12 20:19

toengi1982

4-Sep-12 20:19

Hello
I have a TreeView with a HirarchicalDataTemplate. Within this template I would like to set the background of the TreeViewItem depending on a property behind the template.
Thats my xaml:

HTML

<TreeView.Resources>
            <con:TelegramGroupStateToColorConverter x:Key="TelegramGroupStateToColor"/>
            <HierarchicalDataTemplate 
            DataType="{x:Type tree:ModelTelegramGroup}"
            ItemsSource="{Binding Children}"
            >
               <TextBlock 
               Text="{Binding Path=Group.Name}" 
               Tag="{Binding}" 
               p:ExContextMenu.Menu="{Binding ContextMenu}" 
               Background ="{Binding Path=Group.State, Converter={StaticResource TelegramGroupStateToColor}}"
               />
            </HierarchicalDataTemplate>
         </TreeView.Resources>

In opinion it is not rocket sience but it does not work. I can set a breakpoint within the Converter(TelegramGroupStateToColor) and it will be hit and the correct color will be returned, but the backround remains transperent.
Has anybody an idea what I am doing wrong?

Re: Set background of TreeViewItem within HierarchicalDataTemplate with converter

Wayne Gaylard4-Sep-12 21:57

Wayne Gaylard

4-Sep-12 21:57

You haven't said what your converter returns. Make sure it returns a System.Windows.Media.Brush and not just a Color or a System.Drawing.Brush. Otherwise this should work.

Hope this helps

When I was a coder, we worked on algorithms. Today, we memorize APIs for countless libraries — those libraries have the algorithms - Eric Allman

Re: Set background of TreeViewItem within HierarchicalDataTemplate with converter

toengi19824-Sep-12 22:03

toengi1982

4-Sep-12 22:03

Thanks a lot for the quick answer. You were right.
I returned a System.Drawing.Brush I changed it now and it is working.

Thanks

Re: Set background of TreeViewItem within HierarchicalDataTemplate with converter

Wayne Gaylard4-Sep-12 22:11

Wayne Gaylard

4-Sep-12 22:11

Glad to help

When I was a coder, we worked on algorithms. Today, we memorize APIs for countless libraries — those libraries have the algorithms - Eric Allman

Re: Set background of TreeViewItem within HierarchicalDataTemplate with converter

Mycroft Holmes5-Sep-12 12:52

Mycroft Holmes

5-Sep-12 12:52

It is polite to reward a correct answer with n upvote!

Never underestimate the power of human stupidity
RAH

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