I'm creating a custom TextBox with a Title and I'm trying do it with a template.
The problem is that I don't want to have a textbox inside of textbox.
For example:
<TextBox.Template>
<ControlTemplate TargetType="{x:Type TextBox}">
<StackPanel Height="30" VerticalAlignment="Top" Background="green">
<TextBlock Text="Title"/>
<TextBox Text="{Binding Text, ElementName=txtBox}"/> <!-- How I can do it without this? -->
</StackPanel>
</ControlTemplate>
</TextBox.Template>
This way works like I want but I don't want to recreate the TextBox with binding.
Or is this the right way?
You're not putting "a textbox inside a textbox", you're putting it inside a template. Very different thing. There's still only one textbox, you're just extending its appearance.
If you want fundamental TextBox behavior then you have to use a TextBox in your template, there's not really any way around that. I suspect though that the real problem here isn't so much the TextBox as it is the explicit binding. If that's what you're trying to avoid then you can use a TemplateBinding to bind to the templated control's Text property instead:
<TextBox Text="{TemplateBinding Text}"/>
EDIT: just as a follow-up to this, TemplateBinding is one-way only. If you need two-way binding then use Text="{Binding Text, RelativeSource={RelativeSource TemplatedParent}, Mode=TwoWay}" instead.
Related
I have a custom button set up inside a ListView ItemTemplate. The Listview's ItemSource is bound to a collection of items, pretty standard. I have a few labels in the listview as well, and everything works fine except the button.
Binding the button to one of the properties won't work at all using {Binding buttonName} but it will sort of work if I use {Binding Items/buttonName, ElementName=listView} - the only problem is, when I do it this way, every single button in that listView will have the exact same buttonName.
Now the issue stems from my custom button's DataContext being set to Self; unfortunately, it has to be set to Self because the custom style I'm using needs this. If I try to change the button to a UserControl instead (with the button as a child, and the DataContext set on that), then I can't use the Command property of the button for some reason.
Here's a simplified version of my ListView making use of the custom button:
<ListView x:Name="listView" ItemsSource="{Binding MyPeopleData}">
<ListView.ItemTemplate>
<DataTemplate>
<Grid>
<Label Content="{Binding PersonName}"/>
<ct:RevealButton Content="{Binding Items/recommendation, ElementName=listView}"/>
</Grid>
</DataTemplate>
</ListView.ItemTemplate>
</ListView>
As I said above, this will make every item in the listview use the same recommendation property rather than using it's own one.
If I try to use
<ct:RevealButton Content="{Binding recommendation}"/>
It just won't work, which makes sense given the DataContext of the custom button, which is below:
<Button x:Class="RevealButton" Width="{Binding Width}" Height="{Binding Height}" Background="{Binding ButtonBackground}" DataContext="{Binding RelativeSource={RelativeSource Self}}" Style="{DynamicResource ButtonRevealStyleC}" mc:Ignorable="d">
<Button.ContentTemplate>
<DataTemplate>
<ContentPresenter Content="{TemplateBinding Content}" />
</DataTemplate>
</Button.ContentTemplate>
</Button>
So this ended up being an XY Problem. Because the modified style I was using had a poorly bound property, it was failing when the parent control didn't have a DataContext set to self.
This is what it was:
<SolidColorBrush Opacity="0.8" Color="{Binding ButtonBackground.Color}" />
And ButtonBackground was a dependency property exposed by my custom Button, so binding the style in this way meant it only worked if the Button's context was itself. Changing it to this:
<SolidColorBrush Opacity="0.8" Color="{Binding RelativeSource={RelativeSource TemplatedParent}, Path=ButtonBackground.Color}" />
Fixed the DataContext dependency, which in turn fixes the heirarchy of problems above.
I want to add an exclamation mark Image to the left of the built-in TextBox and make it visible whenever the TextBox Validation.HasError attached property is true, otherwise hide it.
How can I use ControlTemplate to add the Image without having re-bind all the TextBox properties?
<StackPanel>
<StackPanel.Resources>
<ControlTemplate x:Key="TextBoxWithIndicator" TargetType="{x:Type TextBox}">
<StackPanel Orientation="Horizontal">
<!-- Re-bind {Binding Path=Property}, including some that I may miss -->
<TextBox Text="{TemplateBinding Text}" Width="{TemplateBinding Width}" Height="{TemplateBinding Height}"/>
<Image Source="resources/exclaim.png" Visibility="{TemplateBinding Validation.HasError}"/>
</StackPanel>
</ControlTemplate>
</StackPanel.Resources>
<TextBox Template="{StaticResource TextBoxWithIndicator}" Width="120">Happy Go Lucky</TextBox>
</StackPanel>
Note The preceding block of code represents my futile effort in WPF so far. It is probably also wrong on several counts, e.g. probably need a ValueConverter for Visibility <--> Validation.HasError; Setting Width="120" on TextBox seems to adjust the StackPanel width instead of TextBox width despite the TemplateBinding, etc.
I would suggest looking into Adorners. These are special FrameworkElements that are rendered in a special Adorner Layer on top of visual elements, and are intended to provide visual cues to the user.
The above link provides a summary of Adorners as well as an example of a Custom Adorner.
At the moment, I have two very large DataTemplate objects to display two sets of items in two ListBoxes. The DataTemplates are referenced in the ContentTemplate property in two Styles that are set in the ItemContainerStyle properties of the two ListBoxes. The items are of the same type and the DataTemplates are identical except for the following control:
From DataTemplate1
<TextBlock Style="{StaticResource TextStyle}" FontSize="20" Foreground="White"
HorizontalAlignment="Left" Panel.ZIndex="2" Text="{Binding RemainingTime.TotalHours,
Converter={StaticResource DoubleToIntegerConverter}, StringFormat={}{0:#00}}" />
From DataTemplate2
<TextBlock Style="{StaticResource TextStyle}" FontSize="20" Foreground="White"
HorizontalAlignment="Left" Panel.ZIndex="2" Text="{Binding ElapsedTime.TotalHours,
Converter={StaticResource DoubleToIntegerConverter}, StringFormat={}{0:#00}}" />
Is there some way to avoid duplicating the whole Dataemplate but still have this one difference in the text binding of this TextBlock in the second template?
No, there is no inheritance for DataTemplate. If you think about, how would you override a part of a DataTemplate?
Solution: Use another Style to capture the common properties between the two templates. You can scope it in the same Resources block if it only place you need it. It is much cleaner or more WPF way of doing things.
I've already asked this question here once and unfortunately there isn't.
but in this specific situation you can move the fontsize,foreground,horizontalalignment..etc to a style (lets say textstyle2) that based on your current textstyle.
I got an answer to this from another post (by Liz). Basically, you can put all common controls into one DataTemplate and then create two more DataTemplates that each use the first one as a ContentTemplate in a ContentPresenter. Then, you can add different controls into one or both of the latter DataTemplates. Liz provided a code example.
<DataTemplate x:Key="UserTemplate">
<!-- show all the properties of the user class here -->
</DataTemplate>
<DataTemplate DataType="{x:Type local:User}">
<ContentPresenter Content="{Binding}" ContentTemplate="{StaticResource UserTemplate}"/>
</DataTemplate>
<DataTemplate DataType="{x:Type local:Author}">
<StackPanel>
<ContentPresenter Content="{Binding}" ContentTemplate="{StaticResource UserTemplate}"/>
<!-- show all the additional Author properties here -->
</StackPanel>
</DataTemplate>
Thanks once again Liz.
Adding to what Dennis suggested, you can always create a custom control that you just stick inside your DataTemplate and re-style that control instead of the DataTemplate.
I have a DataTemplate I want to reuse. The part I want to factor out is the binding, because it's the only thing that changes. My DataTemplate looks roughly like this. (There's actually quite a bit more to it, but I've taken out the extraneous stuff.)
<DataTemplate>
<TextBox Text="{Binding Name}" />
</DataTemplate>
How can I reuse this DataTemplate while simply varying the property to which I'm binding? (Note that if it were as simple as just a TextBox, I wouldn't worry about it, but the DataTemplate actually contains a StackPanel with a number of other elements in it. I want to centralize that in one place, hence the DataTemplate.)
I've thought about two ways to tackle this problem.
Create a simple custom control. Reuse that, and don't worry about reusing the DataTemplate.
Experiment with some kind of subclass of DataTemplate. (I'm told this is possible.) I'd add a dependency property to it that lets me specify the name of the property to which I want to bind.
Suggestions?
I hate answering my own questions, but for the sake of completeness, here's my solution.
<ListBox ItemsSource="{Binding}">
<ListBox.Resources>
<ControlTemplate x:Key="textBoxControlTemplate" TargetType="ContentControl">
<TextBox Text="{TemplateBinding Content}" />
</ControlTemplate>
</ListBox.Resources>
<ListBox.ItemTemplate>
<DataTemplate>
<ContentControl Content="{Binding Name}" Template="{StaticResource textBoxControlTemplate}" />
</DataTemplate>
</ListBox.ItemTemplate>
</ListBox>
This of course is a very contrived example. In my own app, I'm not actually putting textboxes inside of a listbox. In a listbox, this is not very useful, but imagine it inside of a DataGrid, where each column might be displayed in a similar way, but binds to a different property.
Create a UserControl and use it within the DataTemplate.
<DataTemplate>
<local:MyComplexUserControl DataContext="{Binding Name}"/>
</DataTemplate>
and within the UserControl:
<StackPanel>
<TextBlock>Value:</Text>
<TextBox Text="{Binding}"/>
</StackPanel>
Have a separate DataTemplate with its own binding for each occasion.
How do I set the background colour of items in a list box dynamically? i.e. there is some property on my business object that I'm binding too, so based on some business rules I want the background colour to be different?
<ListBox Background="Red">
<ListBox.ItemContainerStyle>
<Style TargetType="ListBoxItem">
<Setter Property="Background" Value="Red"/>
</Style>
</ListBox.ItemContainerStyle>
<ListBox.ItemTemplate>
<DataTemplate>
<StackPanel Orientation="Horizontal"
Margin="5">
<TextBlock VerticalAlignment="Bottom"
FontFamily="Comic Sans MS"
FontSize="12"
Width="70"
Text="{Binding Name}" />
<TextBlock VerticalAlignment="Bottom"
FontFamily="Comic Sans MS"
FontSize="12"
Width="70"
Text="{Binding Age}" />
</StackPanel>
</DataTemplate>
</ListBox.ItemTemplate>
</ListBox>
EDIT: It says here
In Silverlight, you must add x:Key
attributes to your custom styles and
reference them as static resources.
Silverlight does not support implicit
styles applied using the TargetType
attribute value.
Does this impact my approach?
Ok - if you need custom logic to determine the background then I would look into building a simple IValueConverter class. You just need to implement the IValueConverter interface and, in its Convert method, change the supplied value into a Brush.
Here's a quick post from Sahil Malik that describes IValueConverters - it might help:
http://blah.winsmarts.com/2007-3-WPF__DataBinding_to_Calculated_Values--The_IValueConverter_interface.aspx
To bind your background to more than one property, you can use IMultiValueConverter. It's just like IValueConverter except that it works with MultiBinding to pass more than one value into a class and get back a single value.
Here's a post I found with a run-through on IMultiValueConverter and MultiBinding:
http://blog.paranoidferret.com/index.php/2008/07/21/wpf-tutorial-using-multibindings/
Edit: If IMultiValueConverter isn't available (it looks like Silverlight only has IValueConverter) then you can always pass your entire bound object (eg your Person object) to an IValueConverter and use various properties from that to return your Brush.
#Matt Thanks for the reply. I'll look into triggers.
My only problem is that, the logic for determining whether a row should be coloured is slightly more involved so I cant just checking a property, so I actually need to run some logic to determine the colour. Any ideas?
I guess I could make a UI object with all the relevant fields I need, but I kinda didnt want to take the approach.
You could try binding something in your controltemplate (ie a border or something) to the TemplateBackground. Then set the background on your listbox to determine the colour it will be.
<Border Margin="-2,-2,-2,0" Background="{TemplateBinding Background}" BorderBrush="{TemplateBinding BorderBrush}" BorderThickness="1,1,1,0" CornerRadius="11,11,0,0">