Invoking JavaScript from .NET Synchronously

Learn how to call JavaScript from .NET and vice versa.

We have only looked at invoking JavaScript functions asynchronously. But we can also invoke JavaScript functions synchronously. We do that by downcasting IJSRuntime to IJSInProcessRuntime. IJSInProcessRuntime represents an instance of a JavaScript runtime to which calls may be dispatched.

IJSInProcessRuntime allows our .NET code to invoke JS interop calls synchronously. This can be advantageous because these calls have less overhead than their asynchronous counterparts. The methods are similar to the asynchronous methods:

  • InvokeVoid

  • Invoke

The following code is the synchronous version of the Document component. It uses IJSInProcessRuntime to invoke the JavaScript function synchronously:

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