CODEWITHSUNDEEP
c#blazor
FenryrMKIII
FenryrMKIII

Reputation: 1198

Blazor : call a method without button click

I am learning Razor. I have a very simple Razor component (using MudBlazor framework) in Budget.razor

@page "/budget"

<PageTitle>Budget</PageTitle>

<MudGrid>
    <MudItem xs="12" sm="6" md="4">
        <p> Hello you @HelloConsole() </p>
        </MudItem>
</MudGrid>

and a partial class in Budget.razor.cs :

namespace MyProject.Pages
{
   public partial class Budget
    {
        protected void HelloConsole()
        {
            Console.WriteLine("Hello");
        }
    }
}

I receive the error in Visual studio :

Cannot implicitly convert type 'void' to 'object'

What am I doing wrong ?

Upvotes: 1

Views: 1817

Answers (3)

Bart Calixto
Bart Calixto

Reputation: 19725

You need to execute as annonymous lambda otherwise it will expect a string/object return:

This should work:

@page "/budget"

<PageTitle>Budget</PageTitle>

<MudGrid>
    <MudItem xs="12" sm="6" md="4">
        <p> Hello you @(() => HelloConsole()) </p>
        </MudItem>
</MudGrid>


protected void HelloConsole()
{
    Console.WriteLine("Hello");
}

Upvotes: 1

MrC aka Shaun Curtis
MrC aka Shaun Curtis

Reputation: 30450

<p> Hello you @HelloConsole() </p>

Says put the output from the method HelloConsole() here. But HelloConsole returns a void - exactly what the error says - which the renderer can't handle.

This works:

protected string HelloConsole()
{
   Console.WriteLine("Hello");
   return "I just wrote to the console";
}

Add on to answer:

To execute some code when loading the component:

protected override void OnInitialized()
{
   Console.WriteLine("Hello");
}
// or

protected override Task OnInitializedAsync()
{
   Console.WriteLine("Hello");
   return Task.CompletedTask;

}

Upvotes: 3

Mayur Ekbote
Mayur Ekbote

Reputation: 2080

You are writing to the console. The Blazor markup expects an object (because it basically render a set of string). Change the code to return "Hello". That will work.

Upvotes: 0

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