将值从“选择asp-for”传递到“ textarea” asp.net核心剃须刀

Question

I would like to know how to pass the value of the asp-for select description to a textarea on the same page after user picks the item.

Cshtml:

 <select asp-for="ContasReceberVM.ContasReceber.PessoaId" asp-items="Model.ContasReceberVM.PessoaVM.ToSelectListItemNome(Model.ContasReceberVM.ContasReceber.PessoaId)" class="form-control"></select>

 <textarea asp-for="ContasReceberVM.ContasReceber.Observacao" class="form-control"></textarea>

Answer 1

You're confusing code that runs server-side with user interactions that happen client-side. Once the user can do something like select an item from a drop down list, the server is done . At that point, all you've got is a DOM created from the HTML that was sent as the server's response. You'd need to use JavaScript to access the select element in the DOM and get its currently selected value. Then, you'd also use JavaScript to select the textarea element from the DOM and alter its content.