I have a ListBox which DataTemplate is TextBox that can be edited. Where should I set Binding TwoWay? In ItemSource or In TextBox binding? Maybe in both? And how it works inside? Is it inherited? So if I set Binding in ItemSource - is it inherited in TextBox?
<ListBox HorizontalAlignment="Left" ItemsSource="{Binding Commands, Mode=TwoWay}">
<ListBox.ItemTemplate>
<DataTemplate>
<TextBox Text="{Binding Name}" />
</DataTemplate>
</ListBox.ItemTemplate>
</ListBox>
Two way binding should be setup op your item you need to display, in this case the Textbox. Here you need to have coupling back to your datacontext. You might want to consider setting the UpdateSourceTrigger property to PropertChanged.
This way you will always have entered value of your text, even without loosing focus.
The itemsource should not be Two way. One way will do since you probable will be binding to an observable collection. This will only be set once from your datacontext. This will automatically handle the adding and removing of items to your collection.
I'd add your code like this:
<ListBox Margin="10,0,0,0" Width="200" HorizontalAlignment="Left" ItemsSource="{Binding Commands}" >
<ListBox.ItemTemplate>
<DataTemplate>
<TextBox Text="{Binding Name, Mode=TwoWay, UpdateSourceTrigger=PropertyChanged}"/>
</DataTemplate>
</ListBox.ItemTemplate>
</ListBox>
Where should I set Binding TwoWay?
You should set this Mode for TextBox like this:
<TextBox Text="{Binding Path=Name, Mode=TwoWay}" />
If I'm not mistaken, the Text property is listed TwoWay mode by default. Therefore, it's construction is not required.
From MSDN:
When used in data-binding scenarios, this property uses the default update behavior of UpdateSourceTrigger.LostFocus.
This means that updates the properties were visible at once, you need to set the property UpdateSourceTrigger to PropertyChanged:
<TextBox Text="{Binding Path=Name, Mode=TwoWay, UpdateSourceTrigger=PropertyChanged}" />
So if I set Binding in ItemSource - is it inherited in TextBox?
No, inheritance will not be, because settings of Binding unique for each dependency property. Inheritance happens when using DataContext, but again, settings unique for each property.
Related
I have a ListBox with a DataTemplate like this:
<ListBox ItemsSource="{Binding Reportes,Mode=TwoWay}" >
<ListBox.ItemTemplate>
<DataTemplate >
<StackPanel IsEnabled="{Binding PantallaActiva}">
<CheckBox FontWeight="Bold" HorizontalAlignment="Left"
Content="{Binding NORepo,Mode=TwoWay }"
IsChecked="{Binding Path=EmitirReporte,Mode=TwoWay,UpdateSourceTrigger=PropertyChanged}"/>
<TextBlock FontSize="9" Foreground="Gray" TextWrapping="Wrap" Text="{Binding DSRepo,Mode=TwoWay}" MaxWidth="140" />
</StackPanel>
</DataTemplate>
</ListBox.ItemTemplate>
</ListBox>
The property "PantallaActiva" is a true/false property in my ViewModel that is set to False when some process starts. I need to disable the checkBoxes when that process starts. My problem is that never happens the checkboxes or the stack panel ,can`t see the PantallaActiva property or any other property in my viewModel, they only see the properties in the items collection Reportes[i] and that's, I guess, my problem, so how do I have to do the binding ?
thanks in advance
If I understand your question correctly, the PantallaActiva property isn't part of your Reporte class (the elements in your collection). It's probably a property on your view model instead, right?
The scope of your ItemTemplate is bound to the type Reporte since you bound that collection as the ItemsSource. That's why XAML binding cannot find the property on that type. You need to bind the IsEnabled property to the property on your ViewModel.
<CheckBox IsEnabled="{Binding Path=DataContext.PantallaActiva, RelativeSource={RelativeSource AncestorType=MyControlType}}" .../>
For this to work, you need to set MyControlType to an element up your visual tree whose DataContext is bound to your view model. (probably the parent of your ListBox)
It would be helpful to see the code in your view model.
replace with this. You only need to assign value as false, as by default, it was true.
IsChecked="{Binding Path=EmitirReporte,Mode=TwoWay,UpdateSourceTrigger=PropertyChanged,Value=False}"/>
The ItemsSource (SsString) is a SortedSet string
I want to use a TextBox (not the default TextBlock) in a ListBox but I cannot figure out how to bind to the value in the SortSet.
I have tried binding with no path, Key, key, Value, and value.
<ListBox ItemsSource="{Binding Path=SsString}">
<ListBox.ItemTemplate>
<DataTemplate>
<TextBox Text="{Binding Path=Key}"/>
</DataTemplate>
</ListBox.ItemTemplate>
</ListBox>
The following works but it displays TextBlock.
<ListBox ItemsSource="{Binding Path=SsString}" />
You won't be able to edit the bound values. You need a class as the item so you can target a property with the Binding.Path.
(You should be able to bind this using {Binding .}, but it's one-way)
I am going crazy trying to figure this out without success.
I have a DependencyObject, ("UserObject"). It has a "DataItems" DependecyProperty that is an ObservableCollection. "UserDefiniton" is a DependencyObject with a DependencyProperty of "Data". Data has two properties: DataType (an enumeration) and Value (a string).
I am trying to define a ListBox in XAML that uses the "DataItems" property as its ItemsSource. In the ItemTemplate, I have several different controls. For simplicity of this issue, I am using a CheckBox and a TextBox. I want CheckBox to be available and visible when DataType is 0, while I want the TextBox to be available and visible when the DataType is 1. Only one control can be available and visible at a time.
This works:
<ListBox
ItemsSource={Binding DataItems, Mode=OneWay}>
<ListBox.ItemTemplate>
<DataTemplate>
<StackPanel>
<CheckBox
Visibility="{Binding Path=Data.DataType, Mode=OneWay, Converter={StaticResource VisibilityConverter}, ConverterParameter=0}"
IsChecked="{Binding Path=Data.Value, Mode=TwoWay, Converter={StaticResource StringToBoolean}}" />
<TextBox
Visibility="{Binding Path=Data.DataType, Mode=OneWay, Converter={StaticResource VisibilityConverter}, ConverterParameter=1}"
Text="{Binding Path=Data.Value, Mode=TwoWay}" />
</StackPanel>
</DataTemplate>
<Listbox.ItemTemplate>
</ListBox>
The problem is that even though only one is visible, both are fighting over the Data.Value property (the boolean of the checkbox will show in the textbox, even though the checkbox is hidden).
Basically, though, the binding in this case is working--but the implementation is incorrect.
So, I switched to using Templates. The problem I am having is that I can't get the binding to work.
This is the code that I have for the Template. The Template selector is working correctly, but the Text property of the TextBox and the IsChecked property of the checkbox are not binding to Data.Value:
<DataTemplate x:Key="TextBoxItem">
<TextBox
Text="{Binding Path=Data.Value, Mode=TwoWay}" />
</DataTemplate>
<DataTemplate x:Key="CheckBoxItem">
<CheckBox
IsChecked="{Binding Path=Data.Value, Mode=TwoWay, Converter={StaticResource StringToBoolean}}" />
</DataTemplate>
...
<ListBox
ItemsSource={Binding DataItems, Mode=OneWay}>
<ListBox.ItemTemplate>
<DataTemplate>
<ContentControl
Content="{Binding Path=Data.DataType, Mode=OneWay}"
ContentTemplateSelector="{DynamicResource UserDefinitionTemplateSelector}"/>
</DataTemplate>
<ListBox.ItemTemplate>
</ListBox>
So how do I fix the binding?
Content should be set to {Binding}, since the Content will be the DataContext of the data-templates, hence you should just pass on the current DataContext. If you need to pass specific data to the template selector you can just drill down in the whole object.
There also is a template selector on the level of the ListBox, so you do not really need the internal ContentControl.
(You might also be interested in generic methods of debugging data bindings.)
Why is the first element in my combobox popup menu not shown in the selected item area of
my combobox , when I use the SelectedItem binding? Without that it is showing up ?? Using
the same code selecteditem + selectedindex that is no problem!
<ComboBox
ItemsSource="{Binding SchoolclassSubjectViewModels}"
SelectedItem="{Binding SelectedSchoolclassSubjectViewModel}"
SelectedIndex="0"
Height="23"
HorizontalAlignment="Left"
Margin="375,13,0,0"
VerticalAlignment="Top"
Width="151">
<ComboBox.ItemTemplate>
<DataTemplate>
<StackPanel Orientation="Horizontal">
<TextBlock Text="{Binding SchoolclassName}" />
<TextBlock Text=" " />
<TextBlock Text="{Binding SubjectName}" />
</StackPanel>
</DataTemplate>
</ComboBox.ItemTemplate>
</ComboBox>
Well as workaround I used:
SchoolclassSubjectViewModels.Add(schoolclassSubjectVM);
SelectedSchoolclassSubjectViewModel = schoolclassSubjectVM;
and this:
SelectedItem="{Binding SelectedSchoolclassSubjectViewModel,Mode=TwoWay}"
but I would prefer the xaml only way as it should really work.
It is because the reference inside your ItemsSource collection is not the same as the one in your SelectedItem property. I would venture to guess that you are using one object context to query your database for the list of SchoolclassSubject objects which the ItemsSource is bound to, but another context to query the actual data item to which you bind the SelectedItem. Even though the list contains a reference which represents the value held by your object, it is not really the same reference, but a separate instance of the same data.
There are ways to solve this issue, most of them involve using the SelectedValuePath and SelectedValue instead of the SelectedItem properties, but the concrete solution would be different depending on your particular ORM.
I want to enable / disable a DataGridTextColumn based on whether or not the SelectedValue of its neighboring DataGridComboBoxColumn == 'Other'
I can make this work in a ListBox as below, but this won't work in my DataGrid environment as the DataGridComboBox column doesn't have a name property.
<ListBox Grid.Row="1" Grid.Column="1" ItemsSource="{Binding Source={StaticResource CustomData}}">
<ListBox.ItemTemplate>
<DataTemplate>
<StackPanel Orientation="Horizontal">
<ComboBox Name="operatorComboBox" SelectedValue="{Binding OperatorId}" ItemsSource="{Binding Source={StaticResource Operator}}" SelectedValuePath="Id" DisplayMemberPath="Name"></ComboBox>
<TextBox Text="{Binding Name}" Visibility="{Binding Path=SelectedValue, ElementName=operatorComboBox, Converter={StaticResource intToVis}}"></TextBox>
</StackPanel>
</DataTemplate>
</ListBox.ItemTemplate>
</ListBox>
So can this be done with a DataGrid?
(I know I've changed visibility in the ListBox example, but its not a quantum leap to change that to enabled. (Obviously hiding an entire column would be a bad thing in a proper DataGrid)
this question is fairly similar to what I'm asking, I just can't seam to mangle the solution into what I'm after
The easiest way I can think of solving this problem is actually to create a DataGridTemplateColumn instead of a DataGridTextBoxColumn then create a textbox inside the template. In order to disable / enable the textbox, bind the IsEnabled property to the underlying OperatorId property. You will also have to write a ValueConverter that checks whether the OperatorId value == 'Other' and returns that value.