ASP.NET Core的输入标签帮助程序不会将其文本更改为绑定的模型字段

Question

I'm using the input tag helper for my Razor view like so:

<input type="text" asp-for="MsgFromFilter" id="txtMsgFromFilter" />

So this should be bound to my model's MsgFromFilter string field. Although, when I submit the form, this field in my model is bound to the value in the textbox, it doesn't work the other way round: when I set the value of this field in my controller, the view doesn't set that as the default value of the text input element; it just maintains the last value submitted in that input field. How can I get the text input to default its value on page load to the value in the model rather than the last value that was submitted in the input ?

Answer 1

Thanks to @KirkLarkin I discovered that to set the defaults for the input fields rendered by the Razor view, I need to set ModelState . So in my controller I have to do two things, set ModelState and the model itself:

if (btnReset) {
    ModelState.Remove(nameof(model.MsgFromFilter));
    model.MsgFromFilter = null;
}

This works for resetting the value of that model field as well as the Razor view input element to blank.