Blazor. How to capture mouse in onmousemove event?

Question

How to capture mouse in onmousemove event in Blazor like UIElement.CaptureMouse() in WPF?

Answer 1

... in Blazor like UIElement.CaptureMouse()

The closest match would be Element.setPointerCapture()

In order to use it you will need to get an ElementReference in Blazor with @ref and a JS method to invoke setPointerCapture on it. You need to pass a pointerId that you get from PointerEventArgs.

Do not use the Mouse* related events/methods, they are more or less deprecated in JS.

So you can start with something like:

 <div @ref="myTarget" @onpointerdown="StartCapture">  ... </div>

@code{    
    ElementReference myTarget;

    async Task StartCapture(PointerEventArgs args)
    {
        await JSRuntime.InvokeVoidAsync("myJsFunctions.capturePointer",
                 myTarget, args.PointerId);
    }    
}