Month: September 2019

how to read and write to local Storage using Blazor

first we create a LocalStorageService.cs file

using Microsoft.JSInterop;
using System.Threading.Tasks;

namespace BlazorLocalStorage.Service
{
    public class LocalStorageService
    {
        private readonly IJSRuntime _js;

        public LocalStorageService(IJSRuntime js)
        {
            _js = js;
        }

        public async Task<string> GetFromLocalStorage(string key)
        {
            return await _js.InvokeAsync<string>("localStorage.getItem", key);
        }

        public async Task SetLocalStorage(string key, string value)
        {
            await _js.InvokeVoidAsync("localStorage.setItem", key, value);
        }
    }
}

inject the service in Startup.cs

public void ConfigureServices(IServiceCollection services)
{
    services.AddRazorPages();
    services.AddServerSideBlazor();
    services.AddScoped<LocalStorageService>();
}

Create a new razor component for testing i called it LocalStorage.razor

@page "/localstorage"

@using BlazorLocalStorage.Service
@inject LocalStorageService Storage

<h1>Testing Local Storage!</h1>

<input type="text" @bind-value="Value" @bind-value:event="oninput" />

<p>Current Value: @Value</p>

<button @onclick="SetValue">Save</button>
<button @onclick="GetValue">Read</button>

@code{
    const string key = "blazorKey";

    public string Value { get; set; }

    async Task SetValue()
    {
        await Storage.SetLocalStorage(key, Value);
    }

    async Task GetValue()
    {
       Value = await Storage.GetFromLocalStorage(key);

    }
}

load the app and navigate to /localstorage

type Hello World! and hit save

refresh the page a click read to get the message from local storage.