.net maui Passing Multiple Parameters

Question

.net maui Passing Multiple Parameters

John Rutherford 21

Using Visual Studio Community 17.14.9

.Net9

Maui App

I have an app using MVVM with 8 pages and wish to pass 2 objects (ObsLocation class) and (string) from my ProjectSelectionPageViewModel to my LocationPageViewModel using the following code.

location = new ObsLocation
{
    Id = MaxId + 1, // Increment the Id for the new project
    ProjDescription = "MyProject",
    Latitude = "-10.4540",
    Longitude = "126.0150",
    AlignmentAngle = "28.2440",
    TimeZoneId = TimeZoneInfo.Utc.Id,
};
//save the Location information in the file
LocationService.SaveLocationAsync(location);
// now navigate to the LocationPage with this location
await Shell.Current.GoToAsync(nameof(LocationPage), true, new Dictionary<string, object>
{
    {"ObsLocation", location},
    {"ProjectType", "New"},
});
IsBusy = false;

The code on my LocationPageViewModel is

private string title = string.Empty;

public string Title
{
    get => title;
    set => SetProperty(ref title, value);
}

The ObsLocn value is passed correctly. However the ProjectType (string value) comes through as null.

Can any offer a solution please.

2 answers

Your answer

Answer 1

LocationViewModel code should be

using CommunityToolkit.Maui.Alerts;
using CommunityToolkit.Mvvm.ComponentModel;
using CommunityToolkit.Mvvm.Input;
using SunObs.Models;
using SunObs.Services;
using System.Collections.ObjectModel;
namespace SunObs.ViewModel
{
    [QueryProperty (nameof(Obslocn), "ObsLocation")]
    [QueryProperty(nameof(ProjectType), "ProjType")] 
    public partial class LocationViewModel : BaseViewModel
    {
        public ReadOnlyCollection<TimeZoneInfo> TimeZones { get; }
        [ObservableProperty]
        public required ObsLocation obslocn;
        [ObservableProperty]
        private string projectType;

Answer 2

John Rutherford 21

Solved it myself. The ProjectType was not properly declared in ProjectSelectionPageViewModel

Gade Harika (INFOSYS LIMITED) 250 Reputation points Microsoft External Staff

2025-08-05T04:48:28.31+00:00

Thank you for resolving the issue on your own. We're glad it's been sorted!

We're proceeding to close this case.

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.net maui Passing Multiple Parameters

2 answers

Your answer