How to fire RoutedEvents of TextBlock in ViewModel from code behind in wpf.
Kindly let me know, how I can bind routed events in wpf code behind. Thanks
Well I use this (you will need System.Windows.Interactivity in Silverlight, but I suspect it's similar in WPF):
xmlns:GalaSoft_MvvmLight_Command="clr-namespace:GalaSoft.MvvmLight.Command;assembly=GalaSoft.MvvmLight.Extras.SL4"
xmlns:i="http://schemas.microsoft.com/expression/2010/interactivity"
<TextBlock Text="{Binding InputValue, Mode=TwoWay}">
<i:Interaction.Triggers>
<i:EventTrigger EventName="GotFocus">
<GalaSoft_MvvmLight_Command:EventToCommand Command="{Binding InputValueGotFocusCommand}" />
</i:EventTrigger>
</i:Interaction.Triggers>
</TextBlock>
You can do this easy in Blend
Related
In WPF, a button can be bound to a command.
<Button Command="{Binding DoSomething}">Click me!</Button>
Now I want to do the same to a TabItem:
<TabItem Header="A little tab" ???="{Binding DoSomething}">...</TabItem>
What should ??? be? Or is there another way to do it?
It depends on what do you want to achieve. TabItems have the IsSelected property
IsSelected="{Binding IsSelected}"
that can be bounded TwoWay, and can be used to signal stuff to the ViewModel.
You could also use the fact that you can override the header of the TabItem, and bound it to a command, using Interactivity.
<TabItem TabIndex="0"
Tag="{Binding CurrentPrinterStatus}">
<TabItem.Header>
<Grid Background="Transparent">
<i:Interaction.Triggers>
<i:EventTrigger EventName="MouseDown">
<i:InvokeCommandAction Command="{Binding DoSomething}"/>
</i:EventTrigger>
</i:Interaction.Triggers>
<TextBlock Style="{StaticResource TextBlockSelectedStyle}"
Text="Printers"/>
</Grid>
</TabItem.Header>
Other solutions are to use the SelectionChanged event of the TabControl, and that could allow you to find the ViewModel of the TabItem currently selected.
Hope this ideas atleast help you get a solution to your problem.
I would like to trigger a command in my ViewModel when the pushpin is clicked on the map. How can I achieve this using databinding?
Here is the DataTemplate I am using for the pinpoints:
<DataTemplate x:Key="PushPinTemplate">
<map:Pushpin Cursor="Hand"
map:MapLayer.Position="{Binding Location}">
</map:Pushpin>
</DataTemplate>
A colleague found the solution:
After adding the Nuget Package System.Windows.Interactivity.WPF
and adding the xml namespace
xmlns:i="clr-namespace:System.Windows.Interactivity;assembly=System.Windows.Interactivity"
you can add an EventTrigger to the template, here the full template code, where
CachePushPinClicked is an ICommand
<DataTemplate x:Key="PushPinTemplate">
<map:Pushpin Cursor="Hand"
map:MapLayer.Position="{Binding Location}" >
<i:Interaction.Triggers>
<i:EventTrigger EventName="MouseLeftButtonDown">
<i:InvokeCommandAction Command="{Binding CachePushPinClicked}"/>
</i:EventTrigger>
</i:Interaction.Triggers>
</map:Pushpin>
</DataTemplate>
I am implementing WPF MVVM Wizard and I am wondering about the right approach of performing a DoOperation when a new Wizard’s Page (UserControl) is loaded.
The DoOperation is implemented on the MyWizard.ViewModal class while the UserControl Load is happening at the MyWizard.View namespaces.
How can I connect between the UserControl loaded event to the DoOperation api?
I tried the following:
<xmlns:i="clr-namespace:System.Windows.Interactivity;assembly=System.Windows.Interactivity"
<i:Interaction.Triggers>
<i:EventTrigger EventName="Loaded">
<i:InvokeCommandAction Command="{Binding Path=RunOperation}"/
</i:EventTrigger>
</i:Interaction.Triggers>
RunOperation calls DoOperation.
it doesn’t work, RunOperation is not being called.
This is the right approach or there is a better way to perform an operation at the MyWizard.ViewModal class?
Your approach should work. Have you checked your output console for binding errors? Is RunOperation a command? Is the DataContext of the UserControl already set, when the Loaded event is raised? Have you implemented the triggers like this in your UC?
<UserControl x:Class="..."
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:i="clr-namespace:System.Windows.Interactivity;assembly=System.Windows.Interactivity">
<i:Interaction.Triggers>
<i:EventTrigger EventName="Loaded">
<i:InvokeCommandAction Command="{Binding Path=RunOperation}"/>
</i:EventTrigger>
</i:Interaction.Triggers>
<Grid>
...
</Grid>
</UserControl>
There is a Treeview Control.
<TreeView Name="ProductsHierarchy" FontFamily="Arial"
Background="White" Margin="2"
FontSize="12" SelectedItemChanged ="ProductsHierarchy_SelectedItemChanged">
Is there a way to bind a command for SelectedItemChanged event of the treeview, avoiding the code behind event handler?
Try MVVM Toolkit's EventToCommand.
"Built-in" (from Blend) approach is to use Interactivity
<TreeView Name="ProductsHierarchy" FontFamily="Arial"
Background="White" Margin="2"
FontSize="12" SelectedItemChanged ="ProductsHierarchy_SelectedItemChanged">
<i:Interaction.Triggers>
<i:EventTrigger EventName="SelectedItemChanged">
<i:InvokeCommandAction Command="{Binding SelectedItemChangedCommand}" CommandParameter="argument"/>
</i:EventTrigger>
</i:Interaction.Triggers>
</TreeView>
You must include namespace:
xmlns:i="clr-namespace:System.Windows.Interactivity;assembly=System.Windows.Interactivity"
The disadvantage here is that you have no access to EventArgs. Here's the solution (it's in Polish, but code samples are pretty much self-explanatory).
Using silverlight, we are looking to move the focus to a textbox.
How do you use mvvm-light to trigger gotfocus?
The view contains:
<TextBox Margin="4,4,0,0" Text="{Binding Path=SearchOID, Mode=TwoWay}">
<i:Interaction.Triggers>
<i:EventTrigger EventName="GotFocus">
<cmd:EventToCommand Command="{Binding GotFocusCommand, Mode=TwoWay}"/>
</i:EventTrigger>
</i:Interaction.Triggers>
</TextBox>
How should the ViewModel look?
How do you trigger this from the ViewModel?
Ended up using a TriggerAction, very similar to:
http://www.codeproject.com/Articles/42988/Silverlight-Behaviors-and-Triggers-Making-a-Trigge.aspx