Well i have a control thats placed in a usercontrol and it exposes a ICommand with a DepenceyPropety(ShowCommand),
and then i have a datagrid (wpf toolkit) with a few columns and one of them has a delete button
<Custom:DataGrid Margin="0" ItemsSource="{Binding Todos}" AutoGenerateColumns="False">
<Custom:DataGrid.Columns>
<Custom:DataGridTextColumn Header="Name" Binding="{Binding Name}"/>
<Custom:DataGridTemplateColumn>
<Custom:DataGridTemplateColumn.CellTemplate>
<DataTemplate>
<Button CommandParameter="{Binding}"
Command="{Binding ElementName=ConfirmDeleteDialog, Path=ShowCommand}"
Content="Delete" />
</DataTemplate>
</Custom:DataGridTemplateColumn.CellTemplate>
</Custom:DataGridTemplateColumn>
</Custom:DataGrid.Columns>
</Custom:DataGrid>
<local:ConfirmationDialog x:Name="ConfirmDeleteDialog"
Title="Confirm delete!"
d:LayoutOverrides="Width"
Message="Are you sure that you want to delete the selected todo?"
YesCommand="{Binding DeleteCommand}" />
and as im in a DataTemplate it does not find the element, and i can't combine ElementName and Relative source so how would i define a binding that can access an element declared outside the datatemplate?
The command im trying to bind to is located on ConfirmationDialog.YesCommand..
Well i solved it this way i changed my dialog to a to inherit from ContentControl instead of Control and added a content holder in it..
after that i moved the dialog so it wrapped the whole control, after that i added a routed event that i can listen to and that worked like a charm.
Related
I need to bind a button's command inside a datatemplate like below:
<GridViewColumn.CellTemplate>
<DataTemplate>
<Button Content="-" Cursor="Hand" Width="50"
Background="Red" x:Name="removeButton"
Command="{Binding Remove}" />
</DataTemplate>
</GridViewColumn.CellTemplate>
Unfortunately it does not work. How can I bind a command in a button insade a datatemplate?
I found that thread in the forum:
Bindings in nested WPF DataTemplates
but the method given by person, who answered this question, does not work as well. I think, that something has changed in WPF since this time, I would you grateful for your help.
If Remove is defined in the view model of the parent ListView, you could bind to it using a RelativeSource:
Command="{Binding DataContext.Remove,
RelativeSource={RelativeSource AncestorType=ListView}}"
You could also set the AncestorType to Window or UserControl depending on where the command property is defined and where the DataTemplate is applied.
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.)
I have an XAML tree as follows:
<Window>
<Grid>
<DockPanel>
<DataGrid>
<DataGrid.Resources>
<CheckBox Command="{Binding Command}" CommandParameter="??" />
</DataGrid.Resources>
</DataGrid>
<StackPanel>
<ChartLegend>
</ChartLegend>
<DataChart>
</DataChart>
</stackPanel>
</DockPanel>
</Grid>
</Window>
I want to have DataChart object as CommandParameter on ViewModel from a Command on DataGrid.
My Findings:
I'm getting DockPanel object as CommandParameter, then I have to apply method FindName("") to get the DataChart. And do further modifications.
But I want the DataChart object directly, to avoid TypeCasting or searching down the Tree.
You can keep datachart as a named resource in your DockPanel resources and use static resource binding to command parameter. Then use ContentControl to host it.
like this...
<DockPanel>
<DockPanel.Resources>
<DataChart x:Key="MyDataChart">
</DataChart>
</DockPanel.Resources>
<DataGrid>
<DataGrid.Resources>
<CheckBox
Command="{Binding Command}"
CommandParameter="{StaticResource MyDataChart}" />
</DataGrid.Resources>
</DataGrid>
<StackPanel>
<ChartLegend>
</ChartLegend>
<ContentControl Content="{StaticResource MyDataChart}"/>
</stackPanel>
</DockPanel>
Hoping that you wont use same MyDataChart to host to another area (as that would result in "visual tree parent disconnect" error).
Although I must ask you this... why is there a lonely CheckBox in your DataGrid resources?
Also your's and mine solution breaks MVVM because we are supplying a UI control (Chart control) to a View Model.
I have a form:
<StackPanel Orientation="Horizontal" Visibility="{Binding Editable, Converter={StaticResource visibilityConverter}}"
ToolTipService.ToolTip="Add new topic to this group">
<sdk:AutoCompleteBox Width="160" ItemsSource="{Binding ElementName=LayoutRoot, Path=DataContext.TopicNames}" />
<Button Click="addTopicButton_Click">
<Image Source="Images/appbar.add.rest.png" />
</Button>
</StackPanel>
This form appears in a DataTemplate for an ItemsControl. I'm not sure what the best way is to get the data from the AutoCompleteBox when the button is clicked. I can't give the elements x:Name attributes, because they're in a template (right?).
How can I get around this? The Click event will give me the Button, but I need a reference to the text box. Use the Button's parent, then look through the children for the Textbox? If I factored this out into its own UserControl, I could set x:Name values, but I'd rather not do that.
Any other ideas?
Update: Here is another example of such a problem:
<ListBox x:Name="topicList"
ItemsSource="{Binding Id, Converter={StaticResource topicGroupIDConverter}}"
SelectionChanged="ListBox_SelectionChanged"
HorizontalAlignment="Stretch">
<ListBox.ItemTemplate>
<DataTemplate>
<StackPanel Orientation="Horizontal">
<TextBlock Text="{Binding Name}"
Width="150"
VerticalAlignment="Center"
ToolTipService.ToolTip="{Binding Description}"
ToolTipService.Placement="Right" />
<Button ToolTipService.ToolTip="Remove this topic from this group"
Visibility="{Binding ElementName=topicList,
Path=DataContext.Editable,
Converter={StaticResource visibilityConverter}}"
Click="removeTopicButton_Click"
HorizontalAlignment="Right"
Margin="10,0">
<Image Source="Images/appbar.cancel.rest.png" />
</Button>
</StackPanel>
</DataTemplate>
</ListBox.ItemTemplate>
</ListBox>
When the button is clicked, I want to access topicList.DataContext. However, topicList itself is a DataTemplate in an ItemsControl, so I can't access it using its name from code-behind. How else can I do this?
You can add a property, say SelectedItemInAutoCompleteBox, to your presenter, and then can bind it to the SelectedItem property of AutoCompleteBox, using Mode=TwoWay, like this,
<sdk:AutoCompleteBox SelectedItem="{Binding Path=DataContext.SelectedItemInAutoCompleteBox, Mode=TwoWay}" ... />
You may try the same approach with Text property of AutoCompleteBox, also. See if it solves your problem.:-)
You have several choices:
If you're on Silverlight 5, use the AncestorBinding
Otherwise, use a Silverlight 4 AncestorBinding hack (it doesn't look pretty)
Or you could try DataContextProxy, which stores the DataContext in a resource so that it is accessible. Note: you should set the DataContextProxy as a Resource of topicList ListBox, not the UserControl as in Dan Wahlin's example.
I have a Silverlight DataGrid control inside which I have a textbox and a button control.
It is as under
<dg:DataGrid x:Name="myGrid" AutoGenerateColumns="False">
<dg:DataGrid.Columns>
<dg:DataGridTemplateColumn Header="Name" Width="100">
<dg:DataGridTemplateColumn.CellTemplate>
<DataTemplate>
<TextBox Text="{Binding Name}" x:name="txtName"/>
</DataTemplate>
</dg:DataGridTemplateColumn.CellTemplate>
</dg:DataGridTemplateColumn>
<dg:DataGridTemplateColumn Header="Age" Width="100">
<dg:DataGridTemplateColumn.CellTemplate>
<DataTemplate>
<TextBox Text="{Binding Age}" x:name="txtAge"/>
</DataTemplate>
</dg:DataGridTemplateColumn.CellTemplate>
</dg:DataGridTemplateColumn>
<dg:DataGridTemplateColumn Header="Action" Width="100">
<dg:DataGridTemplateColumn.CellTemplate>
<DataTemplate>
<Button x:Name="btnCilck" Content="Click" Click="btnClick_Click />
</DataTemplate>
</dg:DataGridTemplateColumn.CellTemplate>
</dg:DataGridTemplateColumn>
</dg:DataGrid.Columns>
</dg:DataGrid>
What I want to do is that at runtime I want to fetch the textbox value (txtName) for the row selected.
I mean, say the grid has 10 rows(i.e. 10 textbox's in that particular column; say Column Name) and 10 Buttons in say Action column(let's name it like that).
Now when I click on the 5th rows Click button, I want to get the value from the textbox present in that row.
Thanks in advance.
In the click event handler you can examine the sender's (Button's) DataContext, which will be the item represented by that row and will have the properties Name, Age etc.; you can get the property which is bound to the textbox.
A better design, assuming you designed your app with MVVM, is to have an ICommand in the ViewModel and bind the Button's Command property to that ICommand. In that case you can bind something to the CommandParameter of the button and receive it in the ICommand handler - either the DataContext itself with {Binding} or the actual property you're interested in.
Edit: sorry about going on with the Command bindings, they're not readily available in SL3; there are ways around it though, google it if you're interested. The commanding pattern will much better encapsulate the actions across your application.
There are actually ways to get to the actual contents of the grid cells, but I wouldn't recommend it, as it will come with a lot of overhead and will be fragile in case any of the templates change; it's much better to work with the actual data and leave the controls to do their jobs through bindings.