Blazor Custom Layouts

Most popular web applications have multiple different page layouts.  I can think of 2 different ones off the top of my head, Log In and Main.  You could add a message dialog and your standard CURD pages as well.

Blazor uses a simple implementation to allow you to define the layout of pages.  They provide a main layout as well as allowing you to create any additional layouts you need by inheriting from the Blazor layout component because in Blazor, everything is a component, even the layouts.

Default Layout

Here is the default MainLayout.razor

@inherits LayoutComponentBase

<div class="sidebar">
    <NavMenu />
</div>

<div class="main">
    <div class="top-row px-4">
        <a href="https://docs.microsoft.com/en-us/aspnet/" target="_blank">About</a>
    </div>

    <div class="content px-4">
        @Body
    </div>
</div>

You can see that it inherits from LayoutComponentBase, Navigation section, an about link and then the main body “@Body”.

Custom Layout


@inherits LayoutComponentBase

<div class="main">
<header>
<h1>This is the header</h1>
</header>

<div class="content">
@Body
</div>

<footer>
This is the footer
</footer>
</div>

 This one well inherits from LayoutCompontBase, has a header section, a footer section and the “@Body” tag as well.

When you use the layout, it will place the content of your page in the @Body tag.

Here is the counter page using the default layout page:



Here is the same page but with our custom layout:



You can see that the counter part of the pages shown are the same and just the “master” part of the page changed.

Using Layouts


We have seen that we can set the layout in the component by using @layout.  There are a few other ways we can set the layout.

Start Up


You can set the default layout in the app.razor file:

<Router AppAssembly="@typeof(Program).Assembly">
    <Found Context="routeData">
        <RouteView RouteData="@routeData" DefaultLayout="@typeof(MainLayout)" />
    </Found>
    <NotFound>
        <LayoutView Layout="@typeof(MainLayout)">
            <p>Sorry, there's nothing at this address.</p>
        </LayoutView>
    </NotFound>
</Router>

In this file the default layout is set => DefaultLayout="@typeof(MainLayout)"
We are also setting the layout for when the user hits a page that is not defined will see a different page layout => Layout="@typeof(MainLayout)”

_Imports File


You can define additional layouts in place them in the _Imports.razor file and place the _Import.razor file in any folder and then that layout is available to all files at the level and lower.

Attributes
You can define a layout in the class file as well:
[Microsoft.AspNetCore.Components.LayoutAttribute(typeof(MainLayout))]
public class AdminUsers : Microsoft.AspNetCore.Components.ComponentBase
{
}


Summary


A layout is just a Blazor component, HTML, CSS and code.  You can create any layout page with any functionality to meet your needs.  We saw that you can define a page’s layout in the startup, the component, the class or in the _Imports file.



Comments

Post a Comment

Popular posts from this blog

Yes, Blazor Server can scale!

Image
From the very beginning of the release of Blazor Server naysayers have incorrectly stated that Blazor Server can not scale.  They usually state that the limit is 5,000 concurrent users. There are several misconceptions and wrong assumptions about their statement.  Let's break it down and get a better understanding of Blazor server-side scaling. What is the "limit" for users When Microsoft talks about the need to scale an application, what they are saying is that when a normal response for any concurrent user is taking longer than 200 ms, the system is not performant and needs to scale. We will accept that definition: If any normal user response is taking longer than 200 ms, the system needs to scale for concurrent users. By a normal response, we are referring to a page get, a post, etc.  Large database access requests would not be included in this measurement. What is scaling There are 2 common ways to scale, scale, out horizontally, and scale-up, up vertically. In our di
Read more

Blazor new and improved Search Box

 Back in March, I posted a new Blazor data grid with a search box ( see post ).  Since then I have found a new and improved search box that I wanted to implement.  The search part is implemented the same.  What I added was the ability for the user to narrow down the search by selecting which field they wanted to search on.  This will help the user find what they are looking for and in a large collection, the search will end up being faster. The goal of making the change was to make the search box a new component and have it handle the UI functionality part. Prep Work Here is the prep work I did before adding the search box: Started with the source code from the post listed above. Upgraded the project to .Net 5 Upgraded the Nuget packages that were out of date. Ensured every build and run. Change to a Component I wanted to create a component for the search box so I could use it in other applications.   1. Create a Folder under UIControls called "SearchBox" 2. Created a new raz
Read more

Blazor - Cool Blur Loading Page

Image
  I was working on a project and wanted an original way of showing the user the application was loading besides using the normal "Loading...." text.  I came across a website page and thought I could refactor that into what I was looking for. When my application starts, it displays a full-screen image with a count down while the page loads.  As a special effect, I want to unblur the image the closer it gets to the applicaiton finishing loading.  Once the teh count down is done, we pause for 1 sec, for effect, then proceed to the application.  I think it turned out pretty cool.  See the demo here . I used the server side Blazor project template in my example, but the code should work on any Blazor template. Template changes 1. Rename the original Index.razor page to "home".  Besure to change the routing at the top of the page as well.      @page "/home" 2. Create a new Index.razor page     a. Add routing           @page "/"           @page "/i
Read more