How do I display a server’s date and time on a Blazor component?
Use the DateTime.Now property to display the server’s date and time in a Blazor component. Follow this code snippet to do this. [Index.razor] Refer to this documentation for more details.
How do you convert the date and time to a client’s or user’s time zone in Blazor Server?
To convert the date and time to a client’s or user’s time zone in Blazor Server, use the JavaScript function to get the current offset time difference from UTC in minutes using the GetLocalDateTime() method in Blazor using JavaScript Interop. Display the local time by the current offset time difference. Follow these steps to convert the server time zone to the user’s time zone. To define the TimeZoneService class and the GetLocalDateTime() method, create a new file named TimeZoneService.cs in your project. Inside the TimeZoneService.cs file, define the TimeZoneService class and implement the GetLocalDateTime() method. using Microsoft.JSInterop;namespace BlazorServerApp{ public class TimeZoneService { private readonly IJSRuntime _jsRuntime; private TimeSpan? _userOffset; public TimeZoneService ( IJSRuntime jsRuntime ) { _jsRuntime = jsRuntime; } public async ValueTask GetLocalDateTime ( DateTimeOffset dateTime ) { if (_userOffset == null) { int offsetInMinutes = await _jsRuntime.InvokeAsync(“blazorGetTimezoneOffset”); _userOffset = TimeSpan.FromMinutes(-offsetInMinutes); } return dateTime.ToOffset(_userOffset.Value); } }} To register the time zone service, add the following code snippet to the Program.cs file.[Program.cs] builder.Services.AddScoped(); Create a JavaScript file named BlazorInterop.js within the wwwroot directory and include the provided code snippet in it.[BlazorInterop.js] function blazorGetTimezoneOffset() { return new Date().getTimezoneOffset();} To add a reference to the JavaScript file, open the Pages/_Layout.cshtml or _Host.cshtml file, and include the following line of code:[_Layout.cshtml/_Host.cshtml] <script src=”~/BlazorInterop.js”> Finally, you can utilize the service to display a date and time in your application.[Index.razor] @page “/” @inject TimeZoneService TimeZoneService <h1>Current date and time</h1> <p>Now (UTC): @DateTimeOffset.UtcNow.ToString()</p><p>Now (local): @localTime.ToString()</p> @code { DateTimeOffset localTime; protected override async Task OnAfterRenderAsync ( bool firstRender ) { if (firstRender) { // TODO: Require server render mode while instantiating the component to execute JavaScript in OnInitializedAsync. // In _Host.cshtml: localTime = await TimeZoneService.GetLocalDateTime(DateTimeOffset.UtcNow); } }} Refer to this link for more details. View Sample in GitHub
How do you get the current date and time from client in Blazor WebAssembly?
To get the current data and time from client, use the date object (new Date()) in JavaScript using JavaScript Interop. It will return the browser’s date and time. Following is the code to get the current date and time from the client in Blazor WebAssembly. [Index.razor] [index.html] View Sample in GitHub
How do I implement Google reCaptcha in a Blazor WebAssembly application?
Google reCaptcha is a process that helps to protect websites form spam and abuse. To implement Google reCaptcha in Blazor, refer to the Google reCaptcha script link the WebAssembly app and render the reCaptcha by calling the JavaScript function.Follow these steps to implement Google reCaptcha in Blazor WebAssembly. Add the Google reCaptcha renderer function in a separate JavaScript file under the wwwroot folder.[googlereCaptcha.js] function googleRecaptcha(dotNetObject, selector, sitekeyValue) { return grecaptcha.render(selector, { ‘sitekey’: sitekeyValue, ‘callback’: (response) => { dotNetObject.invokeMethodAsync(‘CallbackOnSuccess’, response); }, ‘expired-callback’: () => { dotNetObject.invokeMethodAsync(‘CallbackOnExpired’, response); } }); }; function getResponse(response) { return grecaptcha.getResponse(response); } Add the reCaptcha script link and reference the reCaptcha.js file source in index.html.[index.html] <body> . . . . . . <script src=”googlereCaptcha.js”></script> <!– reCaptcha rendering script –> <script src=”https://www.google.com/recaptcha/api.js”></script></body > Now call the rendering reCaptcha function in JavaScript from the Razor page using JavaScript Interop and show the reCaptcha response on button click.Note: To start using reCaptcha, you need to generate the API site key for your site. Refer to this link to generate the site key. [Index.razor] @page “/” @inject IJSRuntime JSRuntime @using System.ComponentModel <h3>Google reCAPTCHA</h3> <div id=”google_recaptcha “></div> <button class=”btn btn-primary” @onclick=”ShowResponse”>Show Response</button> <br /> <p>@captchaResponse</p> @code { private string captchaResponse; protected override async Task OnAfterRenderAsync(bool firstRender) { if (firstRender) { await JSRuntime.InvokeAsync<int>(“googleRecaptcha”, DotNetObjectReference.Create(this), “google_recaptcha “, “your-sitekey”); } await base.OnAfterRenderAsync(firstRender); } [JSInvokable, EditorBrowsable(EditorBrowsableState.Never)] public void CallbackOnSuccess(string response) { captchaResponse = response; } [JSInvokable, EditorBrowsable(EditorBrowsableState.Never)] public void CallbackOnExpired(string response) { //… } private void ShowResponse() { captchaResponse = $”The response for the Google reCAPTCHA widget: {captchaResponse}”; } }
How do I call a JavaScript method with parameters in Blazor WebAssembly?
You can call a JavaScript function with parameters using JavaScript Interop. Syntax: To call a JavaScript method with parameters in Blazor WebAssembly, you can follow the code snippet provided below: [Index.razor] [index.html] Refer to this documentation for more information. View Sample in GitHub
