1. SetParametersAsync Name: Id
2. SetParametersAsync Value: e4b049b4-0f21-41d5-8fd2-b3439fdd5b58
3. **OnInitializedAsync OnInit called with ID: e4b049b4-0f21-41d5-8fd2-b3439fdd5b58
4. OnInitializedAsync OnInit called with ID: null

When I use NavigationManager.NavigateTo in my Blazor Server project to navigate to a component with a routeparameter like

@page "/deal/{Id}/edit", the Id parameter is wiped to null on the second call to OnInitializedAsync.

NavigateTo Method:

public void EditDeal()
    {
        NavigationManager.NavigateTo($"/deal/{dealId}/edit");
    }

<a @onclick="EditDeal"

OnInitializedMethod:

protected override async Task OnInitializedAsync()
{
    Console.WriteLine($"OnInitializedAsync OnInit called with ID: {Id}");
    if (Id == null)
    {
        dealInformation = dealInformation.SetDefaults();
    }
    else
    { // Get from DB
        dealInformation = await DealService.Get(Id);
    }
}

I have tried changing the Server rendering from ServerPrerendered to Server with no luck, and have been stuck for hours.

Thanks!

CodePudding user response：

As your only showing us some of your code here's my test setup for your issue which works as expected.

GUIDRouteComponent.razor

@page "/deal/{Id:guid}/edit"

<h3>GUID Route Component</h3>
<div >
    @this.Id
</div>

@code {
    [Parameter] public Guid Id { get; set; }
}

And my Index page:

@page "/Index"
@page "/"
<PageTitle>Index</PageTitle>

<h1>Hello, world!</h1>

Welcome to your new app.

<SurveyPrompt Title="How is Blazor working for you?" />

<div >
    <button  @onclick="this.GoToDeal">Go to Deal</button>
</div>
<div >
    <a href="/deal/e4b049b4-0f21-41d5-8fd2-b3439fdd5b58/edit"> Go to Deal</a>
</div>


@code {
    [Inject] private NavigationManager? NavManager { get; set; }

    protected override void OnInitialized()
        => base.OnInitialized();

    private void GoToDeal()
        => this.NavManager?.NavigateTo("/deal/e4b049b4-0f21-41d5-8fd2-b3439fdd5b58/edit");
}

You say "the Id parameter is wiped to null on the second call to OnInitializedAsync." If you are navigating within your app;lication there should be no second call. This only occurs on the initial page load.