CODEWITHSUNDEEP
blazor
Venkat
Venkat

Reputation: 2196

OnInitializedAsync method is not called

I browse to abc.razor OnInitializedAsync() method gets called.

now in OnvalidSubmit method I have the following code

  NavManager.NavigateTo("/abc?rid=1", false, true);

which means it should navigate to abc.razor page again. It does navigate but doesnot call the OnInitializedAsync() method?

why so?

Upvotes: 1

Views: 1470

Answers (1)

MrC aka Shaun Curtis
MrC aka Shaun Curtis

Reputation: 30545

If you navigate to self, i.e. to the same page, the Router component passes the same route component into RouteView in App.

The Renderer sees no component change so treats the event as a re-render. OnInitialized{Async} is not run.

OnParametersSet{Async} is run and the Rid parameter will be updated. So use OnParametersSet{Async} for your logic.

Here's my Demo Page:

@page "/Reload"
<h3>Reload</h3>
@inject NavigationManager NavManager
<div class="alert alert-info">
    @this.Rid
</div>

<div class="alert alert-primary">
    @this.value
</div>

<BasicComponent [email protected] />

<div class="m-2">
    <button class="btn btn-primary" @onclick=this.ReloadComponent>Reload</button>
</div>
@code {
    private string value = string.Empty;

    [Parameter]
    [SupplyParameterFromQuery]
    public string? Rid { get; set; }

    private void ReloadComponent()
    {
        NavManager.NavigateTo($"/Reload?Rid={DateTime.Now.ToLongTimeString()}");
    }

    protected override void OnParametersSet()
    {
        value = $"Reloaded at {DateTime.Now.ToLongTimeString()}";
    }
}

And BasicComponent.razor:

<h3>BasicComponent</h3>

<div class="alert alert-dark">
    @RID
</div>

<div class="alert alert-secondary">
    @this.value
</div>

@code {
    private string value = string.Empty;
    [Parameter] public string RID { get; set; } = string.Empty;

    protected override void OnParametersSet()
    {
        value = $"Reloaded at {DateTime.Now.ToLongTimeString()}";
    }
}

For Reference

The relevant code in ComponentBase looks like this. _initialized is already true.

    public virtual Task SetParametersAsync(ParameterView parameters)
    {
        parameters.SetParameterProperties(this);
        if (!_initialized)
        {
            _initialized = true;

            return RunInitAndSetParametersAsync();
        }
        else
        {
            return CallOnParametersSetAsync();
        }
    }

Upvotes: 7

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