Xamarin.Forms dynamically change Master page content

Question

I have a simple app with Master-Detail page.

It looks similar:

And I want to dynamically change Master page content. E.g. on Detail page there are some Button and then you click on it - some items from Master page dissapear.

I've tried to find some item properties like item1.isVisible=False but found nothing.

Is there any way I can do it?

MainPage code:

public partial class MainPage : MasterDetailPage
{
    public MainPage()
    {
        InitializeComponent();
        masterPage.listView.ItemSelected += OnItemSelected;
    }

    void OnItemSelected(object sender, SelectedItemChangedEventArgs e)
    {
        var item = e.SelectedItem as MasterPageItem;
        if (item != null)
        {
            Detail = new NavigationPage((Page)Activator.CreateInstance(item.TargetType));
            masterPage.listView.SelectedItem = null;
            IsPresented = false;
        }
    }
}

MainPage XAML:

<MasterDetailPage xmlns=....>
<MasterDetailPage.Master>
    <views:MasterPage x:Name="masterPage" />
</MasterDetailPage.Master>
<MasterDetailPage.Detail>
    <NavigationPage>
        <x:Arguments>
            <views:SomePage/>
        </x:Arguments>
    </NavigationPage>
</MasterDetailPage.Detail>

MasterPage XAML:

    <StackLayout>
    <ListView x:Name="listView" x:FieldModifier="public" Margin="10,50,0,0">
        <ListView.ItemsSource>
            <x:Array Type="{x:Type local:MasterPageItem}">
                <local:MasterPageItem Title="Home" TargetType="{x:Type views:HomePage}" IconSource="nav_icon_home"/>
                <local:MasterPageItem Title="Settings" TargetType="{x:Type views:HomePage}" IconSource="nav_icon_settings" />
                <local:MasterPageItem Title="My Profile" TargetType="{x:Type views:HomePage}" IconSource="nav_icon_profile" />
                <local:MasterPageItem Title="Help" TargetType="{x:Type views:HomePage}" IconSource="nav_icon_help" />
                <local:MasterPageItem Title="About" TargetType="{x:Type views:AboutPage}" IconSource="nav_icon_about"/>
            </x:Array>
        </ListView.ItemsSource>
        <ListView.ItemTemplate>
            <DataTemplate>
                <ViewCell>
                    <Grid Padding="10,10,10,10" ColumnSpacing="10">
                        <Grid.ColumnDefinitions>
                            <ColumnDefinition Width="30"/>
                            <ColumnDefinition Width="*"/>
                        </Grid.ColumnDefinitions>
                        <Image Source="{Binding IconSource}"/>
                        <Label Grid.Column="1" Text="{Binding Title}" TextColor="White" VerticalOptions="Center"/>
                    </Grid>
                </ViewCell>
            </DataTemplate>
        </ListView.ItemTemplate>
    </ListView>
</StackLayout>

MasterPage items:

public class MasterPageItem
{
    public string Title { get; set; }

    public string IconSource { get; set; }

    public Type TargetType { get; set; }
}

So I've implemented INotifyPropertyChanged inside MasterPageItem:

public class MasterPageItem : INotifyPropertyChanged
{
    public string Title { get; set; }

    public string IconSource { get; set; }

    public Type TargetType { get; set; }

    public event PropertyChangedEventHandler PropertyChanged = delegate { };

    private bool isVisible;

    public bool IsVisible
    {
        get { return isVisible; }
        set
        {
            isVisible = value;
            PropertyChanged(this, new PropertyChangedEventArgs("IsVisible"));
        }
    }

}

But how can I bind this to my MasterPage?

Answer 1

Generally speaking, you can change the View of the Master Page by changing the Master-Property of a Xamarin.Forms.MasterDetailPage. If you assigned a Xamarin.Forms.ContentPage to the Master-Property, you can acces it by ((ContentPage)YourMasterDetailPage.Master).Content.

Im sure this question has been answered already 100 times and follows the basic structure of xamarin forms.

Learn MasterDetailPage from scratch here: https://learn.microsoft.com/en-US/xamarin/xamarin-forms/app-fundamentals/navigation/master-detail-page

Since you provided some code now, here's a little example:

void OnItemSelected(object sender, SelectedItemChangedEventArgs e)
    {
        var item = e.SelectedItem as MasterPageItem;
        if (item != null)
        {
            Detail = new NavigationPage((Page)Activator.CreateInstance(item.TargetType));
            item.IsVisible = false; //this would make the clicked item invisible
            masterPage.listView.SelectedItem = null;
            IsPresented = false;
        }
    }

Answer 2

In the end I've implemented 2 different MasterPages, so I can switch between them when needed.

So I have 2 MainPages the 1st one refers to MasterPage1:

<MasterDetailPage.Master>
    <views:MasterPage1 x:Name="masterPage1" />
</MasterDetailPage.Master>

<MasterDetailPage.Detail>
<NavigationPage>
    <x:Arguments>
        <views:SomePage1/>
    </x:Arguments>
</NavigationPage>
</MasterDetailPage.Detail>

The 2nd MainPage2 - to MasterPage2:

<MasterDetailPage.Master>
    <views:MasterPage2 x:Name="masterPage2" />
</MasterDetailPage.Master>

<MasterDetailPage.Detail>
<NavigationPage>
    <x:Arguments>
        <views:SomePage2/>
    </x:Arguments>
</NavigationPage>
</MasterDetailPage.Detail>

I know it's not the best solution, but for my case it's enough.