I want one datetime field's background colour to depend on its value. Like if a certain date is passed, the background changes to red.
Is there a way to make this in XAML?
I know there is no possibility of an "if" condition/instruction, but maybe you guys found some way to implement a similar function.
<Canvas Canvas.Left="893" Canvas.Top="208" Height="25" Width="99" Background="red" Panel.ZIndex="-1"/>
<assembly:FieldControl Canvas.Left="890" Canvas.Top="206" FieldControlType="DateControl" FormField="{x:Null}" Height="25" LabelColumnWidth="0" Refnr="123456789" ShowCaption="False" StateImageAlignment="Hidden" Width="106" FontSize="10" Foreground="DimGray"/>
this is my code so far. The Canvas-Part makes the Background go red.
I also tried to put the background property in the "FieldControl" but there it's useless.
EDIT:
After getting the information, that Data Binding could help me with this problem, i tested it like this:
<TextBox Canvas.Left="890" Canvas.Top="226" Name="Date" Width="99" Height="25" VerticalAlignment="Top" Text="{Binding ElementName=Date, Path = SelectedItem.Content, Mode = TwoWay, UpdateSourceTrigger = PropertyChanged}" Background="{Binding ElementName=Date, Path=SelectedItem.Content}">
But this is not the direction, i need. Do you have maybe any suggestion, how I can use Data binding to solve my problem?
Yes, it is possible. The concept you need to learn is XAML Data Binding.
You can implement the IValueConverter for this.
https://learn.microsoft.com/en-us/xamarin/xamarin-forms/app-fundamentals/data-binding/converters
You can check the value on binding and return the background color.
how to give different text color for each item of listview in xamarin forms
Related
I have to create a control which aligns some of its button on the left and some others on the right in one row.
I've immediatly thinked to WPF Toolbar so I've typed:
...
<ToolBarTray DockPanel.Dock="Top">
<ToolBar ToolBarTray.Locked="True" Width="{Binding ElementName=Tray, Path=ActualWidth}">
<DockPanel>
<ToolBarPanel DockPanel.Dock="Left">
<Button ...>
</ToolBarPanel>
<ToolBarPanel DockPanel.Dock="Right">
<Button ...>
</ToolBarPanel>
</DockPanel>
</ToolBar>
</ToolBarTray>
...
but this didn't work: the buttons with dockpanel.dock = right are just attached on the right of the first ToolBarPanel and, if I've understood something about xaml, this is absolutely correct, that's why I tried forcing the width of the toolbar.
If I use a Grid with a spacing column, the right ToolBarPanel moves correctly to the right, but my control needs to be resized and I guess there's no easy way to assign the correct width to the column.
Is there some easier way to achive my task?
I have a pivot that I am trying to keep from gaining focus when the user hits the tab key. I immediately tried to set IsTabStop to false. However this wasn't keeping a user from tabbing into the pivot. So I tried testing IsTabStop on two buttons and the behavior was exactly what I expected from the pivot.
Here is my xaml:
<Pivot IsTabStop="False">
<PivotItem Header="Test">
<StackPanel Spacing="10">
<Button Content="Button 1" IsTabStop="True"/>
<Button Content="Button 2" IsTabStop="False"/>
</StackPanel>
</PivotItem>
</Pivot>
Am I missing something here or is there a way around this?
Setting tab index to -1 only makes it first, try something like 1001.. In here they explain the issue you may be having but for RichTextBlock, there are various attributes available for it to set.. https://learn.microsoft.com/en-us/windows/uwp/design/accessibility/keyboard-accessibility
So what i ended up doing is overriding the default style on the pivot. I changed the "HeaderClipper" in the style to have IsTabStop="False", this fixed my problem.
The documentation for the default pivot style can be found at https://msdn.microsoft.com/en-us/library/windows/apps/mt299144.aspx
I am trying to create a ListView cell data template with a label that shows either a "detailed" description or a "short" description based on whether another variable ViewLevel is "Detailed" or "Short".
I am using an IValueConverter and trying to bind the ConverterParameter, but that does not work as I don't think the ConverterParameter is bindable.
Is there a best practice for doing this?
The label I currently have is:
<Label Binding Options, Converter={viewModels:DetailLabelConverter}, ConverterParameter='Detail'}" />
It works, but obviously has the hardcoded Detail view. I've also tried:
<Label Text="{Binding Options, Converter={viewModels:DetailLabelConverter}, ConverterParameter={Binding Source={x:Reference BasePage}, Path=BindingContext.ViewLevel}}"/>
Which works, insomuch as it calls the DetailLabelConverter. Unfortunately the parameter is not loaded with the value of ViewLevel but a Xamarin.Forms.Binding object.
It seems like this should be a fairly common pattern but I can't find a reasonable solution.
If i have 9 TextBlock declared on the XAML file like this:
<TextBlock Name="cellText_00" Tag="0"/>
<TextBlock Name="cellText_01" Tag="1"/>
<TextBlock Name="cellText_02" Tag="2"/>
<TextBlock Name="cellText_20" Tag="3"/>
...
<TextBlock Name="cellText_22" Tag="8"/>
There is a way to interact with it from the .cs getting exactly the desired tag element?
For instance is it possible to give all the same name and get it in this way:
TextBlock tb = get(cellText,0);
where the first field is the name and the second one is the tag?
No, you can't use the same name for many controls.
However there is a workaround: using the FindName method:
http://msdn.microsoft.com/en-us/library/system.windows.frameworkelement.findname(v=vs.95).aspx
There Why can't I access a TextBox by Name with FindName()?
you can find an example and a solution related to namespaces issues.
FindName uses a string to retrieve the control. So you can do something like this: FindName("cellText_" + identifier); and take the element you need.
#Sandrouos, I don't think he's using the same name.
This blogpost explains it perfectly:
http://blog.jerrynixon.com/2012/09/how-to-access-named-control-inside-xaml.html
I want to make a TextBlock visible only when a collection is empty. I have a ListView that is data-bound to the collection already and that's simple. I just want to display something else when the ListView is otherwise empty.
I wrote an IValueConverter that would take the collection, or count, or whatever I need, and return a Visibility appropriately. The XAML looks like this:
<TextBlock Visibility="{Binding Count, ElementName=ContactsList, Converter={StaticResource visibilityWhenEmpty}}"
Text="No contacts yet. Add one using the AppBar below." />
The trouble is that binding just the collection itself only calls my value converter once, when it's empty, and not again when the contents of the collection changes (kinda makes sense). And when, as shown above, I try binding against the collection's Count property, it doesn't call my value converter at all.
Any ideas?
I have faced the same issue. I applied a tricky solution. It might work for you as well. Taks a temporary combo box and bind the collection with that.
<ComboBox x:Name="TempComboBox"
ItemsSource="{Binding DataContext.ContactsList,
RelativeSource={RelativeSource Mode=FindAncestor,AncestorType=UserControl}}" >
<ComboBox.Template>
<ControlTemplate>
<!--Add file button..-->
<TextBlock Content="Your text..."
>
<TextBlock.Visibility>
<Binding Path="Items.Count"
RelativeSource="{RelativeSource Mode=FindAncestor,AncestorType=ComboBox}"
Converter="{StaticResource visibilityWhenEmpty}">
</Binding>
</TextBlock.Visibility>
</TextBlock>
</ControlTemplate>
</ComboBox.Template>
</ComboBox>
You could use notifyPropertyChanged for Count, or implement using BindableBase.