Restore Layout does not restore the modules content - prism

i"m using prism with AvalonDoc.
when i try to restore the layout (on the event handler of the menu button "RestoreLayout")
dockManager.RestoreLayout(FileName);
i do get the correct layout structure, but the content of every region is now empty. do i need to reload to modules or something like that ?
the avalondoc code im my xaml code is something like that:
<ad:ResizingPanel ad:ResizingPanel.ResizeWidth="*" Orientation="Vertical" VerticalAlignment="Top">
<ad:DockablePane ad:ResizingPanel.ResizeHeight="150" prism:RegionManager.RegionName="RegionDocPane1">
<ad:DockableContent Name="DocContent1" HorizontalAlignment="Left"/>
</ad:DockablePane>
</ad:ResizingPanel>
<ad:DockableContent Name="DocContent2" HorizontalAlignment="Right"/>
</ad:ResizingPanel>
</ad:DockingManager>

It won't restore your content because Avalon dock (and most docking mechanisms) don't and can't store your user-controls state. You need to do this manually.

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Cancelcommand is not working in sfdatepicker in xamarin forms

I want normal cancel functionality on cancel button click of sfdatepicker footer, I am trying to achieve it by binding command but it is not working. Could any one suggest me any solution for that ?
You can use code like below:
<datePicker:SfDatePicker.FooterView>
<Grid>
<Button Text="Ok"
x:Name="footerViewButton"
Clicked="footerViewButton_Clicked"/>
</Grid>
</datePicker:SfDatePicker.FooterView>
Created in this way, and then create the corresponding method in the ViewModel to achieve logical operations.

How to create LibVLCSharp custom playback controls in Xamarin Forms?

I've been searching for days now for a guide on how to create the custom playback controls for LibVLCSharp that everyone seems to talk about, which I never found a guid for.
I simply want to create other buttons with event handlers for the bottom playback control panel, I tried this but throws a System.NullReferenceException exception on startup while getting into break mode...
<vlc:MediaPlayerElement MediaPlayer="{Binding MediaPlayer}" LibVLC="{Binding LibVLC}">
<vlc:MediaPlayerElement.PlaybackControls>
<vlc:PlaybackControls>
<vlc:PlaybackControls.ControlTemplate>
<ControlTemplate>
<Grid>
<StackLayout Orientation="Horizontal" HorizontalOptions="CenterAndExpand">
<Button Grid.Column="0" Text="Test 1"/>
<Button Grid.Column="1" Text="Test 1"/>
<Button Grid.Column="2" Text="Test 1"/>
</StackLayout>
</Grid>
</ControlTemplate>
</vlc:PlaybackControls.ControlTemplate>
</vlc:PlaybackControls>
</vlc:MediaPlayerElement.PlaybackControls>
</vlc:MediaPlayerElement>
I want it to act just like the original one (Auto hides, overlays on tapping, etc...) but with my own layout and controls. I also thought about using the existing one and try to override their handler to implement my own code and override the text property for each button to change its icon but no luck of finding any help.
Thanks in advance ^_^
The code you are interested in is here: https://code.videolan.org/videolan/LibVLCSharp/-/blob/3.x/src/LibVLCSharp.Forms/Shared/Themes/Generic.xaml
I also thought about using the existing one and try to override their handler to implement my own code and override the text property for each button to change its icon
That'd be the way to go.
This previous SO question might answer your question: https://stackoverflow.com/a/14217500/4064749
Just create a new Style based on PlaybackControlsStyle, override what you want and then set it on the PlaybackControls element.
I created https://code.videolan.org/videolan/LibVLCSharp/-/issues/309 recently to track the need of a tutorial to customize the MediaElement.
Further docs on style inheritance: https://learn.microsoft.com/en-us/xamarin/xamarin-forms/user-interface/styles/xaml/inheritance
I finally found the problem which was making exceptions, when I create custom control template which completely correct, the MediaPlayerElement code behind by LibVLCSharp developers itself cannot find the elements with the names defined anymore as they used hardcoded names for the buttons and views instead of using bindings and dynamic setters.
Thus, several workarounds could be made to fix such issue, here are some of my ideas:
Use the generic style documented here and modify it without removing any elements but rather hide them out or overlay them.
Create your own style with controls obtaining the same names of the original ones.
Find a way to modify or maybe create a whole new playback control element using the original one which can be found here and here.
Thanks to mfkl's answer which helped me find out how everything worked under the hood to come up with the explaination, even though this took me a couple of days to figure out.

Getting out of memory exception while loading image using 'FFImageLoading.CachedImage' in xamrinform

I want to show list of images in single page as like gallery. In my xaml page I am creating single wrap view, in that wrap view I have
add ffimageloader for loading images. Here I have gave list of image url' to that wrap view contain ffimageloader. When I called that page it shows fallowing error.
system.outofmemoryexception: out of memory at ffimageloading.platformimageloadertask..... like that. many post's suggest if we using ffimageloader instead of image tag we will reduce this type of issues but still getting same issues after using this one also. I am running my application in xamarin android. Please suggest any idea.
Here is the sample code what I have tried
<CustomWrapView x:Name="SampleGalleryView" ItemsSource="{Binding GalleryImages}">
<CustomWrapView.ItemTemplate>
<DataTemplate>
<ffimageloading:CachedImage Source="{Binding ImageUrl}" />
</DataTemplate>
</CustomWrapView.ItemTemplate>
</CustomWrapView>
Take a look at FFImageLoading's downsampling capabilities. You can read more about it here: https://github.com/luberda-molinet/FFImageLoading/wiki/Xamarin.Forms-API#downsampling-properties
If you have a lot of items, you should use some view which is capable of doing items virtualisation (I suspect that WrapView isn't), like: ListView / CarouselView, etc

How to add a button to first item in ListView

Greeting,
I'm developing an apps for Windows Phone 8.1 and face some problem with ListView.
I wanted to place a button for the FIRST item in ListView, but it seem like I can't align center the button.
Below is the code I use currently:
<ListView>
<Button Content="Jio!" Height="6" Width="362"/>
<ListViewItem Content="ListViewItem"/>
</ListView>
Adding horizontalalignment='center' just wont work for the button.
The reason I want to do this is because I wanted the button to scroll together with the list, hence I'm placing it inside the ListView.
Please advice what can I do to achieve my purpose, thanks!
I recommend using the ListView.Header content to place such a button instead of adding it as a child directly.
<ListView>
<ListView.Header>
<Button ... HorizontalAlignment="Center" />
</ListView.Header>
</ListView>
By default, the ListViewItems are left-aligned. You will eventually have to replace their Template in order to center-align it (HeaderTemplate Property).

Change Content of a ListFooterTemplate of LongListSelector

Follow -up to the answer of this question :Add a Load More Button at the end of ListBox without losing Virtualization?
With this example :
<toolkit:LongListSelector ItemsSource="{Binding Items}">
<toolkit:LongListSelector.ListFooter>
<Grid>
<Button x:Name="btnReadMore" Content="ReadMore"/>
</Grid>
</toolkit:LongListSelector.ListFooter>
Is there a way to change his Content by the C# ? (= "ReadMore" and when the itemsource=0 "go back") thank you !
You can bind the value of the Content property to some ViewModel property. This is the best way IMHO:
You would also bind the Command property to some ViewModel command and this will ensure that you correctly set the caption and handle the result.
But beware, you are not supposed to have a button saying "Go Back" which, when pressed, acts as a hardware back button. You are not supposed to emulate such system functionality.

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