如何在Angularjs中禁用按钮时允许ng-click

I have the following form:

我有以下表格：

<form name="formuser" action='/signup' method='post' novalidate>

    <input type="text" name="firstname" ng-model="firstname" ng-class="{ 'has-error' : (formuser.firstname.$invalid && !formuser.firstname.$pristine) || hasSubmitted}" required />

    <button type="submit" ng-disabled="formuser.$invalid" ng-click="hasSubmitted=true">Submit</button>
</form>
<form na