New .Net MAUI App project throws 'The name 'InitializeComponent' does not exist in the current context' build errors

Question

I've attempted to start playing with .Net MAUI and I've setup my development environment following the steps as described in:

1. https://docs.microsoft.com/en-us/dotnet/maui/get-started/first-app?pivots=windows
2. https://docs.microsoft.com/en-us/windows/apps/project-reunion/set-up-your-development-environment#required-workloads-and-components
3. https://docs.microsoft.com/en-us/xamarin/android/get-started/installation/android-emulator/device-manager?tabs=windows&pivots=windows

I've also run the 'maui-check' CLI tool and everything checks out, but when I create a new .NET MAUI App with Visual Studio 2019 v16.11.0 Preview 2.0 (running on Windows 10 Home 20H2), I get the 'The name 'InitializeComponent' does not exist in the current context' build errors. It also doesn't find the references to any controls on the form e.g. 'The name 'CounterLabel' does not exist in the current context'

I've tried almost everything in this post The name 'InitializeComponent' does not exist in the current context which contains suggestions like adding and removing files, making changes and changing them back... basically everything except throwing a penny in a wishing well.

I found that a common mistake is a namespace mismatch, but here is what I have showing that the namespaces are correct:

App.xaml:

<Application xmlns="http://schemas.microsoft.com/dotnet/2021/maui"
             xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
             xmlns:local="clr-namespace:MauiApp1"
             x:Class="MauiApp1.App">
    ...
</Application>

App.xaml.cs

using Microsoft.Maui;
using Microsoft.Maui.Controls;
using Microsoft.Maui.Controls.PlatformConfiguration.WindowsSpecific;
using System;
using Application = Microsoft.Maui.Controls.Application;

namespace MauiApp1
{
    public partial class App : Application
    {
        public App()
        {
            InitializeComponent(); <-- This is throwing the build error...
        }

        protected override IWindow CreateWindow(IActivationState activationState)
        {
            this.On<Microsoft.Maui.Controls.PlatformConfiguration.Windows>()
                .SetImageDirectory("Assets");

            return new Microsoft.Maui.Controls.Window(new MainPage());
        }
    }
}

MainPage.xaml:

ContentPage xmlns="http://schemas.microsoft.com/dotnet/2021/maui"
             xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
             x:Class="MauiApp1.MainPage"
             BackgroundColor="{DynamicResource PageBackgroundColor}">

            ...
</ContentPage>

MainPage.xaml.cs

using System;
using Microsoft.Maui.Controls;

namespace MauiApp1
{
    public partial class MainPage : ContentPage
    {
        public MainPage()
        {
            InitializeComponent(); <-- This is throwing the build error...
        }

        int count = 0;
        private void OnCounterClicked(object sender, EventArgs e)
        {
            count++;
            CounterLabel.Text = $"Current count: {count}"; <-- This is throwing the build error...
        }
    }
}

Any help will be greatly appreciated!

---=== UPDATE ===---

The path to the project I created is c:\develop\c#...... as soon as I copy the project to a folder that doesn't contain 'c#' it works. This clearly causes some parsing in the background to fail.

Answer 1

I faced the same issue and looks like when I created a ContentPage in VS its still pointing to Xamarin Forms. After changing namespace to MAUI, I updated the Build Action(RightClick on Xaml Page>>Properties>>BuildAction) of XAML Page to MauiXaml and it worked for me.

Answer 2

1. Close VS2022
2. Open VS2022
3. Open project with menu VS2022(File - Open - Project...)

Answer 3

The path to the project I created is c:\develop\c#...... as soon as I copy the project to a folder that doesn't contain 'c#' it works. This clearly causes some parsing in the background to fail.

Answer 4

A very simple answer but has happened to me a few times.

Make sure you are using the preview version of VS 2022. It is very easy to accidently open up any other version of VS, which will cause the error to occur.

Answer 5

I have found a workaround for this problem. I am a newbie to c# and especially to .net Maui therefore, my apologies if I misinterpreted things differently.

First things first The error is about the context that the InitializeComponent() resides in. Context is nothing but the nuget package dependency that the file is looking for.

To change the context

1. Open the .cs file and at the top of the editor click the navigation bar as shown in the Image
2. Change the context to Windows specific dependency from the list.

And also the other workaround would be to change the build action of the xaml file to MauiXaml as others mentioned

Answer 6

Your restore command is restoring the whole database. Depending on how the dump was created you can restore specific tables.

Depending on how your dump was taking you can use restore specific tables.

pg_dump

pg_restore

I would create a dump from the original db using the format method. If thats not possible, its usually done to restore the table elsewhere and copy the data across either with a db link or foreign server, depending on your set up.