I have a method like below. I will like to call a javascript function and return the result in to a variable

        private async Task Checker()
        {
           var result = (await JsRuntime.InvokeVoidAsync("checkNullValues");
        }

Here is the javascript function

        function checkNullValues() {
            return $('.k-grid-container .excelGridCell').length === 0 && $('.k-textbox').length == 0;
        }

In the Checker method, I kept getting this error message

"cannot implicitly convert type void to string"

Is it not possible to do this?

I have a method like below. I will like to call a javascript function and return the result in to a variable

        private async Task Checker()
        {
           var result = (await JsRuntime.InvokeVoidAsync("checkNullValues");
        }

Here is the javascript function

        function checkNullValues() {
            return $('.k-grid-container .excelGridCell').length === 0 && $('.k-textbox').length == 0;
        }

In the Checker method, I kept getting this error message

"cannot implicitly convert type void to string"

Is it not possible to do this?

• javascript
• blazor-server-side

Share Improve this question Follow asked Aug 27, 2021 at 20:12 BabaBaba 2,22999 gold badges5353 silver badges9494 bronze badges

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1 Answer 1

Sorted by: Reset to default 5

If you expect to receive values from Javascript function using JSInterop, you should use InvokeAsync method instead of InvokeVoidAsync, indicating the datatype expected to retrieve. For example I suppose that you want to receive a bool, so:

private async Task Checker()
{
    var result = await JsRuntime.InvokeAsync<bool>("checkNullValues");
}