AngularJS清理表单，确保提交后验证错误

<form name="myForm">
  <input type="text" name="username" ng-model="user.username" required>
  <input type="password" name="password" ng-model="user.password" required>
  <button type="submit" ng-click="submitForm()">提交</button>
</form>

angular.module('myApp', [])
  .controller('myController', function($scope) {
    $scope.submitForm = function() {
      if ($scope.myForm.$valid) {
        // 表单验证通过，执行提交操作
        // ...
      } else {
        // 表单验证失败，处理错误
        // ...
      }
      // 清理表单
      $scope.myForm.$setPristine();
      $scope.myForm.$setUntouched();
      $scope.user = {}; // 清空表单数据
    };
  });