Blazor WASM: Inheritance Does not Render mark up from Inherited class-CodePudding

This line of code: "base.BuildRenderTree(__builder);" does not compile.

I'm trying to add a base component that will handle some downloadable data that is needed on every page.

I can pass my dependency injection, and properties through inheritance, but I can't get the mark up from the base component to render. __builder is not exposed, and I can't override BuildRenderTree.

Anyone know what the deal is?

CodePudding user response：

As you haven't provided any code to work with here's some code that demonstrates the various techniques you can use within the standard ComponentBase implementation.

Here's a base component to inherit from:

// MyBasePage.razor
<h3>MyBasePage</h3>

<p>This is content in the base page</p>

<p>@ChildRenderFragment</p>

@code {
    protected RenderFragment Footer(string FooterMessage) => (__builder) =>
        {
            <div >@FooterMessage</div>
        };

    protected virtual RenderFragment ChildRenderFragment => (__builder) =>
    {
        <div>Child Content Goes Here</div>
    };

    protected virtual RenderFragment? BaseContent { get; set; }
}

And an inherited page:

@page "/"
@inherits MyBasePage

@BaseContent

@code {
    protected override RenderFragment BaseContent => (builder) => base.BuildRenderTree(builder);

    protected override RenderFragment ChildRenderFragment => (__builder) =>
    {
        <div >
        This is the child content
        </div>
        @this.Footer("Cold Elm Coders")
    };
}

The code is a little convoluted because ComponentBase is tied down so there's no access to modify the RenderFragment that's submitted to the Renderer.

If you want a more elegant solution you need to write your own ComponentBase. See my answer to this question for one.