ActionMethodSelectorAttribute的使用

• 判断Controller请求是否来自Ajax

[HttpGet]
        [AjaxOnly]
        public ActionResult GetList()
        {
            var data = dTImgIBLL.GetList();
            return JsonResult(data);
        }

　　

AjaxOnlyAttribute的定义如下：

[AttributeUsage(AttributeTargets.Method)]
    public class AjaxOnlyAttribute : ActionMethodSelectorAttribute
    {
        /// <summary>
        /// 初始化仅允许Ajax操作
        /// </summary>
        /// <param name="ignore">跳过Ajax检测</param>
        public AjaxOnlyAttribute(bool ignore = false)
        {
            Ignore = ignore;
        }

        /// <summary>
        /// 跳过Ajax检测
        /// </summary>
        public bool Ignore { get; set; }

        /// <summary>
        /// 验证请求有效性
        /// </summary>
        /// <param name="controllerContext">控制器上下文</param>
        /// <param name="methodInfo">方法</param>
        public override bool IsValidForRequest(ControllerContext controllerContext, System.Reflection.MethodInfo methodInfo)
        {
            if (Ignore)
                return true;
            return controllerContext.RequestContext.HttpContext.Request.IsAjaxRequest();
        }
    }

　　

• 检查Post数据的“名称”。如果Post的表单有一个名为“cancelorder”的名称-值对，则将执行Action方法

• Nopcommerce项目：srcPresentationNop.Web.FrameworkControllersFormValueRequiredAttribute.cs

[HttpPost]
        [FormValueRequired("save")]
        public virtual IActionResult ProductAddPopup(AddProductToCategoryModel model)
        {
            if (!_permissionService.Authorize(StandardPermissionProvider.ManageCategories))
                return AccessDeniedView();

            //get selected products
            var selectedProducts = _productService.GetProductsByIds(model.SelectedProductIds.ToArray());
            if (selectedProducts.Any())
            {
                var existingProductCategories = _categoryService.GetProductCategoriesByCategoryId(model.CategoryId, showHidden: true);
                foreach (var product in selectedProducts)
                {
                    //whether product category with such parameters already exists
                    if (_categoryService.FindProductCategory(existingProductCategories, product.Id, model.CategoryId) != null)
                        continue;

                    //insert the new product category mapping
                    _categoryService.InsertProductCategory(new ProductCategory
                    {
                        CategoryId = model.CategoryId,
                        ProductId = product.Id,
                        IsFeaturedProduct = false,
                        DisplayOrder = 1
                    });
                }
            }

            ViewBag.RefreshPage = true;

            return View(new AddProductToCategorySearchModel());
        }

　　

public override bool IsValidForRequest(RouteContext routeContext, ActionDescriptor action)
        {
            if (routeContext.HttpContext.Request.Method != WebRequestMethods.Http.Post)
                return false;

            foreach (var buttonName in _submitButtonNames)
            {
                try
                {
                    switch (_requirement)
                    {
                        case FormValueRequirement.Equal:
                            {
                                if (_validateNameOnly)
                                {
                                    //"name" only
                                    if (routeContext.HttpContext.Request.Form.Keys.Any(x => x.Equals(buttonName, StringComparison.InvariantCultureIgnoreCase)))
                                        return true;
                                }
                                else
                                {
                                    //validate "value"
                                    //do not iterate because "Invalid request" exception can be thrown
                                    string value = routeContext.HttpContext.Request.Form[buttonName];
                                    if (!string.IsNullOrEmpty(value))
                                        return true;
                                }
                            }
                            break;
                        case FormValueRequirement.StartsWith:
                            {
                                if (_validateNameOnly)
                                {
                                    //"name" only
                                    if (routeContext.HttpContext.Request.Form.Keys.Any(x => x.StartsWith(buttonName, StringComparison.InvariantCultureIgnoreCase)))
                                        return true;
                                }
                                else
                                {
                                    //validate "value"
                                    foreach (var formValue in routeContext.HttpContext.Request.Form.Keys)
                                        if (formValue.StartsWith(buttonName, StringComparison.InvariantCultureIgnoreCase))
                                        { 
                                            var value = routeContext.HttpContext.Request.Form[formValue];
                                            if (!string.IsNullOrEmpty(value))
                                                return true;
                                        }
                                }
                            }
                            break;
                    }
                }
                catch (Exception exc)
                {
                    //try-catch to ensure that no exception is throw
                    Debug.WriteLine(exc.Message);
                }
            }
            return false;
        }

　　

以下其他功能，还没有研究，有待补充：

1、控制Action，实现不同角色同一Action跳转到不同View

2、限制Action的提交方式，实现同一Action接受不同的或两种以上的提交方式(同时接受Post、Put等)

3、实现同一form多个submit动作，提交到不同的Action