WPF pass parameter to page with factory delegate - wpf

Question

I dont how to pass parameter to new page, I have factory delegate that help me with dependecy injection but I also want to pass parameter throught Navigate service.
App.xml
private void ConfigureServices(ServiceCollection serviceCollection)
{
serviceCollection.AddTransient<Home>();
serviceCollection.AddSingleton<Func<Home>>(ServiceProvider => ServiceProvider.GetService<Home>);
serviceCollection.AddTransient<PrinterDetails>();
serviceCollection.AddSingleton<Func<PrinterDetails>>(ServiceProvider => ServiceProvider.GetService<PrinterDetails>);
serviceCollection.AddTransient<ProvinceList>();
serviceCollection.AddSingleton<Func<ProvinceList>>(ServiceProvider => ServiceProvider.GetService<ProvinceList>);
serviceCollection.AddSingleton(Configuration);
serviceCollection.AddTransient<ISqlDataAccess, SqlDataAccess>();
serviceCollection.AddTransient<IProvinceListViewModel, ProvinceListViewModel>();
serviceCollection.AddTransient(typeof(MainWindow));
}
I navigate from page PrinterDetails to page ProvinceList using NavigationService(when i click btnProvince_Click())
public partial class PrinterDetails : Page, INotifyPropertyChanged
{
private Func<ProvinceList> ProvinceListFactory { get; }
public PrinterDetails(Func<ProvinceList> provinceListFactory)
{
InitializeComponent();
DataContext = this;
PrinterService printerService = new PrinterService();
cmbPrinterList.ItemsSource = printerService.PrinterList();
ProvinceListFactory = provinceListFactory;
}
private void btnProvince_Click(object sender, RoutedEventArgs e)
{
ProvinceList nextPage = this.ProvinceListFactory.Invoke();
NavigationService.Navigate(nextPage);
}
}
ProvinceList page that i want to pass parameter
public partial class ProvinceList : Page
{
private readonly IProvinceListViewModel _provinceListViewModel;
public ProvinceList(IProvinceListViewModel provinceListViewModel)
{
InitializeComponent();
_provinceListViewModel = provinceListViewModel;
GetProvinceList();
}
private void GetProvinceList()
{
//How to get parameter from previous page
}
}

Answer 1

You can implement a public property on ProvinceList. Then PrinterDetails can set this property after it has created the instance using the factory:
private void btnProvince_Click(object sender, RoutedEventArgs e)
{
double parameter = 4.5;
ProvinceList nextPage = this.ProvinceListFactory.Invoke();
nextPage.Value = parameter;
NavigationService.Navigate(nextPage);
}
Alternatively, you can add this parameter to the constructor of ProvinceList and then configure the IoC container to inject the parameter. If the parameter is a dynamic result you must configure your factory to accept this parameter.
Register the factory delegate that accepts a parameter e.g. Func<IProvinceListViewModel, double, ProvinceList>, which is used to construct the type:
// This example assumes that the constructor of ProvinceList
// requests two parameters of type IProvinceListViewModel and double
serviceCollection.AddSingleton<Func<double, ProvinceList>>(serviceProvider => doubleParameter =>
{
IProvinceListViewModel viewModel = serviceProvider.GetService<IProvinceListViewModel>();
return new ProvinceList(viewModel, doubleParameter);
});
serviceCollection.AddTransient<IProvinceListViewModel, ProvinceListViewModel>();
And use the factory as follows:
public PrinterDetails(Func<double, ProvinceList> provinceListFactory)
{
InitializeComponent();
ProvinceListFactory = provinceListFactory;
}
private void btnProvince_Click(object sender, RoutedEventArgs e)
{
double constructorParameter = 4.5;
ProvinceList nextPage = this.ProvinceListFactory.Invoke(constructorParameter);
NavigationService.Navigate(nextPage);
}
Answer to follow up question:
// This example assumes that the constructor of ProvinceList
// requests two parameters of type IProvinceListViewModel and double
serviceCollection.AddSingleton<Func<double, ProvinceList>>(serviceProvider => doubleParameter =>
{
IProvinceListViewModel viewModel = serviceProvider.GetService<IProvinceListViewModel>();
Func<POPList> popListFactory = serviceProvider.GetService<Func<POPList>>();
return new ProvinceList(viewModel, doubleParameter, popListFactory);
});
serviceCollection.AddTransient<IProvinceListViewModel, ProvinceListViewModel>();
serviceCollection.AddTransient<POPList>();
serviceCollection.AddSingleton<Func<POPList>>(serviceProvider => serviceProvider.GetService<POPList>);
private void btnProvince_Click(object sender, RoutedEventArgs e)
{
double constructorParameter = 4.5;
ProvinceList nextPage = this.ProvinceListFactory.Invoke(constructorParameter);
NavigationService.Navigate(nextPage);
}