Xamarin.Forms — Xamarin Community Forums

I am fairly new to Xamarin. I'm currently working on a project and am trying to use best MVVM practices in building it. I've successfully implemented the MVVM pattern for my login page and I have a pretty good grasp on that, but it is a little more straight forward than what I'm trying to do now.

Once you log in you're brought to a TabbedPage. The TabbedPage contains two ContentPages, one with a ListView. My goal is to create an ObservableCollection which can be accessed by both of the ContentPages in the TabbedPage but I'm not sure where the correct place to create this ObservableCollection would be.

Should I create a ViewModel for the TabbedPage and have the ObservableList live there and have the ViewModels for the two ContentPages access that ViewModel? Should I create the ObservableList in the ViewModel of the first ContentPage with the ListView and have the second ContentPage reference that ViewModel?

I've tried looking for resources to understand this particular scenario but I haven't been able to find any that discuss multiple views referencing the same ObservableList. I'd be very grateful for either an explanation on the best way to do this, or a link to a resource that would explain or exemplify this. Thanks!

I should also note that I currently have the ObservableList living in the code behind for the ContentPage with the ListView. I know this is not where it should be but I just wanted to make sure I could get the ListView working with an ObservableList and I am now looking to move it to where it should be.

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Hi,

today I experimented a bit with the "new" (not that new anymore) shell component in order to set up a simple hamburger menu.
I'm facing the same issue as with the MasterDetailPage in the past, were the animation of closing the menu is stuck for a second before actually closing.
For the Masterdetail it was solved by adding a delay (which was bad already) but I can't find a way to solve it for shell.

Does anyone know how to improve the closing animation? Right now it is unusable.

Here is my xaml setup:

<?xml version="1.0" encoding="UTF-8"?>
<Shell BackgroundColor="#D4503B"  xmlns="http://xamarin.com/schemas/2014/forms" xmlns:page="clr-namespace:MyApp.ContentPages" xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml" x:Class="MyApp.AppShell">
    <FlyoutItem Title="Dashboard" >
            <Tab>
                <ShellContent ContentTemplate="{DataTemplate page:Page1}"/>
            </Tab>
    </FlyoutItem>
    <FlyoutItem Title="Train ticket request">
            <Tab>
                <ShellContent ContentTemplate="{DataTemplate page:Page2}" />
            </Tab>
    </FlyoutItem>
    <FlyoutItem Title="Parking spot reservation">
            <Tab>
                <ShellContent ContentTemplate="{DataTemplate page:Page3}" />
            </Tab>
    </FlyoutItem>
</Shell>

Page 1 is almost empty, just two buttons without any styling are shown there but the same problem. Page2 and 3 are a bit more complex but still not overwhelmingly crazy.

One of my ideas was to manually tell when to open and close and navigate but I didn't find a way how to implement it (For example, how to get the menu icon click event?)
Any ideas?

I'm using Xamarin.Forms 4.3.0.947036

References confirming the bug (One is marked as solved but clearly isn't):
https://github.com/xamarin/Xamarin.Forms/issues/7521
https://github.com/xamarin/Xamarin.Forms/issues/5216

References to fix MasterDetail in the past:
https://github.com/xamarin/Xamarin.Forms/issues/4398
https://stackoverflow.com/questions/48115810/how-can-i-make-the-masterdetailpage-faster-on-android

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How to have a frame centered in the screen. The frame will have only a Label, an Entry of maximum 6 numbers width and a button.

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Hi all,

Context:
I have the task of putting into production an application made by a tier, which will be called TA to update an application made historically by the company CB. TA has recoded the entire application, so it is more like the old, but I want to release the version under the guise of an update to not lose the thousands of users of the application. It remains the same application. My problem is that I can't take ownership of the signature entities and make Visual Studio detect signing certificates.

Actual config:
Certificate
Provisionning Profile
App ID
Archive Visual Studio

I have test with XCode, and XCode in Auto Sign add CB in the Signing Certificate, but, this certificate not exist today and it is not linked with this App ID.

Today I am completely helpless and I really have no idea how to do it. I spent 2 days, so I passed my dead line. If a charitable soul could yell me, I thanked him for it.

Thanks for your help.

Best way to implement an ObservableCollection whose objects are accessible from multiple views?