Visibility converter based on another element width - xaml

I have a Silverlight application and I use MVVM.
I would like to display or hide a TextBlock, based on another element current width (or window width at least...). The problem is that I currently have 2 texts on each other if I reduce the width of my window so I need want to hide the second textblock in that case...
I'm a beginner and I know how to use a VisibilityConverter with a boolean from my ViewModel, but not like this...

To bind to a property of another element, you would do something like this:
Visibility="{Binding ActualWidth,
ElementName=TheThingWhoseWidthYouAreBindingTo,
Converter={StaticResource WidthToVisibilityConverter}}"
And then create yourself a WidthToVisibilityConverter that takes the width value and returns a Visibility value.

Related

Text Trimming without ellipses in Windows Phone 8.1

I want to customize TextBlock control to remove its ellipses(three dots at end) for TextTrimming="WordEllipsis". But since TextBlock does not have template property I cannot customize its trimming ellipses. Is there a way to remove those dots in case ellipses shown?
there is no official way to do this. what you could do is abuse TextWrapping property instead.
Remove the trimming and set TextWrappping to WrapWholeWords this will move all remaining text to a next line. if you combine this with a MaxHeight that you hard code to the height of 1 line it should get the same effect.
<TextBlock TextWrapping="WrapWholeWords" MaxHeight="30">

Set VerticalAlignment of LongListMultiSelector content

I'm using the LongListMultiSelector of the WP Toolkit to select multiple items. I've written a DataTemplate, which is a little bit complex and have a hight of round about 140px. Now I want to change the position of the Checkbox to VerticalAlignment Top to VerticalAlignment Center. I've tried to change the style of the LongListMultiSelector, but this doesn't work.
Has anybody an idea?
It's the LongListMultiSelector's ItemContainerStyle. Here you find the toolkit's styles. Copy the < Style x:Key="LongListMultiSelectorItemListStyle" TargetType="controls:LongListMultiSelectorItem">, change the x:Key, and change the line which says < CheckBox x:Name="SelectBox" VerticalAlignment="Top" ...

Datbinding element in list to an item outside of the list

I'm using XAML for a windows phone apps, and I'm binding a collection to graph control within the listbox Itemtemplate. Everything shows correctly except that the Horizontal axis is scaled per the data in the grid and I want them all scaled the same.
I've worked out the Maximum value - which need to establish the data binding - as its in a listbox itemtemplate I can't simply set the value in code. And for the data binding I only seem to see the elements in the collection but the value I have is not an element of the collection.
Is it possible to bind to a property/field of the page - that way I can set the value and all the grids can just bind to this property/fields.
One possible way to bind element inside ListBox item template to property of the page is by using ElementName binding. Simply name the page, then you can set binding source by page name, for example :
<phone:PhoneApplicationPage
..........
..........
x:Name="myPage">
<Grid x:Name="LayoutRoot" Background="Transparent">
<TextBlock Text="{Binding ElementName=myPage, Path=Name}" />
</Grid>
</phone:PhoneApplicationPage>
Above sample will display text "myPage" in the TextBlock. That way of binding also works for elements inside DataTemplate for ListBox item.

How to show a grid view inside a grid view?

I am developing a windows 8 app. And I want to display a GridView inside of another GridView item template. And I have added a visibility binding to the inner GridView, but the binding doesn't work when wrapping the GridViewItems in the outer GridView. It works when i use a simple ListView or GridView without any wrapping.
This is the main GridView with wrapping
<GridView
Name="feedGridView"
Background="Transparent"
SelectionMode="None"
ItemTemplate="{StaticResource MyFeedGridView}">
<GridView.ItemsPanel>
<ItemsPanelTemplate>
<VariableSizedWrapGrid Height="600" Orientation="Vertical" />
</ItemsPanelTemplate>
</GridView.ItemsPanel>
</GridView>
The style for "MyFeedGridView" which contains another GridView
<DataTemplate x:Key="MyFeedGridView">
<Grid HorizontalAlignment="Left" Width="500">
<StackPanel x:Name="gridViewStackPanel" Orientation="Horizontal" >
<GridView
HorizontalAlignment="Right"
x:Name="myFeedGridViewInListView"
ItemTemplate="{StaticResource MyFeedGridViewInListView}"
ItemsSource="{Binding listContent}"
Height="100"
Visibility="{Binding listContent,Converter={StaticResource FeedListToVisibilityConverter}}"
SelectionMode="None"
Width="400" />
</StackPanel>
</Grid>
</DataTemplate>
I am using a converter to hide or show the inner GridView. The below is the converter that i am using
public object Convert(object value, Type targetType, object parameter, string language)
{
List<ContentList> contents = value as List<ContentList>;
return (contents != null && contents.Count > 0) ? Visibility.Visible : Visibility.Collapsed;
}
My problem is that the inner GridView gets hidden for all the items or gets visible for all the items irrespective of the listcontent that I have bound.
I have noticed is that this is happening only when I set the ItemsPanel. If I remove the VariableSizedWrapGrid property then it's working as expected. But I need to wrap the items after each column so I can't do away with it.
Please let me know if you have any clue why this is happening.
Thanks
EDIT:
Attaching image of how the grid view items should be arranged. If you see the first item of the grid view, it has another grid view inside the grid view item representing songs. So this inner grid view will be empty for some items and populated for some. So I had written a visibility converter to show and hide the inner grid view. And when am using the converter,if the first grid view item has inner grid view items(songs then it will show inner grid view for all the items and if the first grid view item doesnt have any inner grid view items(songs) then it hides inner grid view for all the main grid view items.
Let me know if its not clear.
The problem with a GridView is that it uses the same size for all its GridViewItems by default. You can use a VariableSizedWrapGrid as its ItemsPanel, but that will disable virtualization and so you won't be able to use your GridView with a large number of items (more than a few dozen) without incurring performance cost.
For your scenario you could use a GridView with a non-uniform ItemsSource - one where some items represent the main list item and some that represent lists of songs and use the ItemTemplateSelector to specify which template to use for which type of item. It's not ideal of course, but this is what your easiest option is. One problem is that some of these song lists might end up orphaned in a different column than the item they are associated with, so for the ugly workaround you might need to figure out the number of items per column and in the list also include empty items or rearrange the items so that the empty-end-of-column items are filled with items that don't have any song lists associated with them.
A better option might be to use a VariableSizedWrapGrid as ItemsSource or simply use a manually populated Grid and add a more... item at the end that opens a ListView, since vertical lists IMHO are easier to scroll than horizontal GridViews. You would still need to use a non-uniform ItemsSource and ItemTemplateSelector to get the desired layout and keep virtualization of the list, but that's what you get.

Slider control shows abnormal behaviour on {Binding} with TextBlock

Sorry if title is weird , because the problem itself is kinda weird.
I have a TextBlock and Slider Control on Clientside.
The Slider is {Binding} to Textblock.
This is the code for them -
<TextBlock Text="{Binding Value}" x:Name="Name1Value" FontSize="25"/>
<Slider ValueChanged="slider_ValueChanged_1" x:Name="slidervalve" Value= "{Binding ElementName=Name1Value,Path=Text}" StepFrequency="25" />
Now when Slider Value changes,Slider calls a method slider_ValueChanged_1,which sends its value to server. The server accepts the value and sends the new value back to client and this new value from server is set to the textblock( x:Name="Name1Value") through an observablecollection with inotifypropertychanged implemented. The slider is {Binding} to textblock.
1)Now the first time i change the value on slider on client, the server accepts the new value and returns the new value and i am setting the new value to textblock.
2)Now i am changing the value on server and the value is correctly updated in textblock and then the slider value changes to textblock value.
3) now after this first cycle,if i change the value on server again ,the textblock on client is getting updated but the slider does not change to textblock value.
But the slider is bound to textblock. How can i solve this?
Edit1: FYI , the textblock and the slider are in same page but in different stackpanels
A Slider control's Value property is of type double, while TextBlock.Text is a string. Binding these two together without a converter is asking for trouble. You should bind your Slider.Value to the DataContext/view model and typically make sure the binding Mode=TwoWay.