Develop Reference

How to customize the navigation title view of MAUI ContentPage

In Xamarin, I frequently used <NavigationPage.TitleView> to customize the navigation title bar in my views. Now that I am working in MAUI, this tag seems to have no effect on a ShellItem view.
Here is AppShell.xaml:
<?xml version="1.0" encoding="UTF-8" ?>
<Shell
x:Class="MyApp.AppShell"
xmlns="http://schemas.microsoft.com/dotnet/2021/maui"
xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
xmlns:localize="clr-namespace:FleetHDMobile.Resources.Strings"
xmlns:local="clr-namespace:FleetHDMobile.Views"
Shell.FlyoutBehavior="Disabled">
<ShellItem Route="MainPage">
<ShellContent
Title="MainPage"
ContentTemplate="{DataTemplate local:MainPage}"
/>
</ShellItem> . . .
Here is MainPage.xaml:
<?xml version="1.0" encoding="utf-8" ?>
<ContentPage xmlns="http://schemas.microsoft.com/dotnet/2021/maui"
xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
xmlns:localize="clr-namespace:FleetHDMobile.Resources.Strings"
Shell.FlyoutBehavior="Flyout"
x:Class="FleetHDMobile.Views.MainPage">
<NavigationPage.TitleView>
<Label
Text="XXX"
HeightRequest="44"
WidthRequest="300" />
</NavigationPage.TitleView>
<ScrollView>
I have tried making MainPage a tab in the tabbar, but that didn't customize the title view either.
The <NavigationPage.TitleView> tag has no effect on the rendered view. I would like to put small logo icons in the title bar, but cannot figure out how to do so.

There are some known issues about this problem.
You can follow up them here:
https://github.com/dotnet/maui/issues/9269
https://github.com/dotnet/maui/issues/9687
Thanks for your support and feedback.

Did you try doing it through the ViewModel or the .cs of your View ?
Such as for MainPage.xaml.cs or MainPageViewModel.cs
public class MainPageViewModel
{
public MainPageViewModel
{
Title = “”; // or this.Title = “”;
}
}

Xamarin conditional xaml based on compilation directive

I need the same as
Does XAML have a conditional compiler directive for debug mode?
but in Xamarin xaml; i've tried the proposed solution but i get this error:
Type mc:Choice not found in xmlns http://schemas.openxmlformats.org/markup-compatibility/2006
I've tried to use xcc https://github.com/firstfloorsoftware/xcc, but it seems not working with .netstandard 2.0 / Xamarin.Forms 4.5

Its little different in XAML of Xamarin. There is Design time namespacing in Xamarin.
You would use markup-compatibility xml name space and mark design namespace as Ignorable
<?xml version="1.0" encoding="utf-8" ?>
<ContentPage xmlns="http://xamarin.com/schemas/2014/forms"
xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
xmlns:d="http://xamarin.com/schemas/2014/forms/design"
xmlns:ref="clr-namespace:XamUtilities.Views;assembly=XamUtilities"
mc:Ignorable="d"
x:Class="Sample.MainPage">
<ContentPage.Content>
<d:Label Text="This will be displayed only in previewer"/>
<Label Text="This will be displayed in actual app"/>
</ContentPage.Content>
</ContentPage>
In code behind also you can set values
[DesignTimeVisible (true)]
public partial class MainPage : ContentPage
{
public MainPage ()
{
InitializeComponent ();
if (DesignMode.IsDesignModeEnabled)
{
// Previewer only code
//add your bindings in here
}
}
}

Xamarin App won't launch when trying to make popup page

I have a problem. I am using the Nuget package: Rg.Plugins.Popup.Pages with this colorPicker: Spillman.Xamarin.Forms.ColorPicker.
I created this page:
<?xml version="1.0" encoding="utf-8" ?>
<pages:PopupPage xmlns="http://xamarin.com/schemas/2014/forms"
xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
xmlns:pages="clr-namespace:Rg.Plugins.Popup.Pages;assembly=Rg.Plugins.Popup"
xmlns:animations="clr-namespace:Rg.Plugins.Popup.Animations;assembly=Rg.Plugins.Popup"
x:Class="Memento.Dialogs.ColorPicker"
xmlns:colorPicker="clr-namespace:Spillman.Xamarin.Forms.ColorPicker;assembly=Spillman.Xamarin.Forms.ColorPicker">
<pages:PopupPage.Animation>
<animations:ScaleAnimation
PositionIn="Center"
PositionOut="Center"
ScaleIn="1.2"
ScaleOut="0.8"
DurationIn="400"
DurationOut="300"
EasingIn="SinOut"
EasingOut="SinIn"
HasBackgroundAnimation="True"/>
</pages:PopupPage.Animation>
<pages:PopupPage.BindingContext>
<colorPicker:ColorPickerViewModel />
</pages:PopupPage.BindingContext>
<ContentView HorizontalOptions="Center" VerticalOptions="Center"
Padding="8" BackgroundColor="White">
<colorPicker:ColorPickerView />
</ContentView>
</pages:PopupPage>
But when I try to define the page like this: ColorPicker_Popup = new ColorPicker(); I get the following error:
Android.Content.Res.Resources+NotFoundException: 'Resource ID #0x7f0700c3'
What am I doing wrong?

Can't you do it like this?
await PopupNavigation.PushAsync(new ColorPicker(), true);

Xamarin Start-up

I am a newbie in Xamarin. I created a C# cross-platform project, after the project has been created there were several errors I don't know why these errors occurred. How can I fix these errors? When I click build nothing displays. When I click Play my default app does not display.
App.xaml
<?xml version="1.0" encoding="utf-8" ?>
<Application xmlns="http://xamarin.com/schemas/2014/forms"
xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
x:Class="App1.App">
<Application.Resources>
</Application.Resources>
</Application>
MainPage.xaml
<?xml version="1.0" encoding="utf-8" ?>
<ContentPage xmlns="http://xamarin.com/schemas/2014/forms"
xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
xmlns:local="clr-namespace:App1"
x:Class="App1.MainPage">
<StackLayout>
<!-- Place new controls here -->
<Label Text="Welcome to Xamarin.Forms!"
HorizontalOptions="Center"
VerticalOptions="CenterAndExpand" />
</StackLayout>
</ContentPage>
MainPage.xaml.cs
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using Xamarin.Forms;
namespace App1
{
public partial class MainPage : ContentPage
{
public MainPage()
{
InitializeComponent();
}
}
}

Try to reinstall the Xamarin with Visual studio , It seems there has been something missing form installation. You can find the documentation here
https://learn.microsoft.com/en-us/xamarin/cross-platform/get-started/installation/windows
Regards

Right click on your project
Manage Nuuget Packages
Installed tab : Check if Xamarin is intalled, if yes update it, if not install xamarin
Clean and rebuild your project.

Xamarin forms navigation

I am having trouble with Xamarin forms navigation, as in, it does not work at all.
My code :
appname.cs
using System;
using Xamarin.Forms;
namespace List
{
public class App : Application {
public App () {
MainPage = new NavigationPage (new HomePage ());
}
}
}
homepage.xaml.cs
using System;
using Xamarin.Forms;
using System.ComponentModel;
using System.Globalization;
namespace List
{
public partial class HomePage : ContentPage {
public HomePage () {
InitializeComponent ();
}
public void OnButtonClicked (object sender, EventArgs args) {
Navigation.PushAsync (new DetailsPage ());
}
}
}
My intention is obviously to open a main page, have a button on there that goes to a second page upon press.
However this happens instead whenever the button is clicked:
error message
Could not load type 'UIKit.UIView_UITextField' from assembly 'Xamarin.Forms.Platform.iOS'.
Can someone tell me what I'm doing wrong here?
Edit - code for DetailsPage, since this could be source of error:
using System;
using System.Collections.Generic;
using Xamarin.Forms;
namespace List
{
public partial class DetailsPage : ContentPage
{
public DetailsPage ()
{
InitializeComponent ();
}
}
}
Edit 2 - code for Xaml pages (thanks for the help everyone, I really appreciate it):
Homepage.xaml
<?xml version="1.0" encoding="UTF-8"?>
<ContentPage xmlns="http://xamarin.com/schemas/2014/forms" xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml" xmlns:local="clr-namespace:List" x:Class="List.HomePage">
<ContentPage.Title>
1
</ContentPage.Title>
<Button Text="Click Me!" HorizontalOptions="Center" VerticalOptions="CenterAndExpand" Clicked="OnButtonClicked" />
</ContentPage>
DetailsPage.Xaml:
<?xml version="1.0" encoding="UTF-8"?>
<ContentPage xmlns="http://xamarin.com/schemas/2014/forms" xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml" x:Class="List.DetailsPage">
<Label Text="LOL"/>
</ContentPage>

In your xaml, the first element needs to be a layout (if you have multiple elements). I would try something similar to below and see if anything changes.
HomePage.xaml
<?xml version="1.0" encoding="UTF-8"?>
<ContentPage xmlns="http://xamarin.com/schemas/2014/forms" xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml" xmlns:local="clr-namespace:List" x:Class="List.HomePage" Title="1">
<StackLayout>
<Button Text="Click Me!" HorizontalOptions="Center" VerticalOptions="CenterAndExpand" Clicked="OnButtonClicked" />
</StackLayout>
</ContentPage>
DetailsPage.xaml
<?xml version="1.0" encoding="UTF-8"?>
<ContentPage xmlns="http://xamarin.com/schemas/2014/forms" xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml" x:Class="List.DetailsPage">
<StackLayout>
<Label Text="LOL"/>
</StackLayout>
</ContentPage>
Also, I noticed you were setting your title like using ContentPage.Title 1 ContentPage.Title. This is unnecessary. Just set the title directly in your ContentPage tag as I showed in the above example.

Well, I was having the same problem as you. I came across this solution of the xamarin guide.
It seems that in app.cs you need to call the using Xamarin.Forms.Xaml;
Right above your namespace insert [assembly:XamlCompilation(XamlCompilationOptions.Compile)]
But I really can't tell why. I'm Looking for the reason. Try to see if it resolves. In my case went well. Sorry about the bad english and the bad edit of the post, kind of new to this. But comparing all your code, it was missing this piece for you too, maybe this is the reason.
EDIT (12/01/2017) - Add
i found this, that might explain why was not working, seems like the function that we are using is part of a new set for Xamarin that helps him to became faster.
I can be wrong, if I am, please correct me someone that knows better.

Navigation.PushModalAsync(new DetailsPage());
Reference: http://developer.xamarin.com/guides/cross-platform/xamarin-forms/introduction-to-xamarin-forms/#Navigation