使用多个字段过滤/搜索 - ASP.NET MVC [英] Filter/Search using Multiple Fields - ASP.NET MVC

问题描述

我将 ASP.NET MVC 与 EF 6 一起使用.

I am using ASP.NET MVC with EF 6.

我有一个库存页面，其中显示了有关库存商品的所有信息.现在我也想过滤记录.

I have a stock page which shows all the information on stock items. Now I want to filter records too.

在下图中，我有 3 个选项.我可能会按每个选项进行过滤，一次一个或两个或三个的组合.

In picture below I have 3 options. I might filter by each option, one at a time or by combination of two or with all three.

我正在考虑为每个选择的选项编写 linq 查询.但是如果过滤器选项增加，这是不可能的.有没有更好的方法.

I was thinking of writing linq query for each and every options selected. But this wouldn't be possible if filter option increases.Is there is any better way to this.

谢谢！

这是我在我的控制器中所做的.(目前下拉列表有两个选项，不包括:--选择一个--")

This is what I did in my controller.(currently dropdown has two options, excluding : " -- select one -- ")

public ActionResult StockLevel(string option, string batch, string name)
{
    if (option != "0" && batch == "" && name == "")
    {
        if(option == "BelowMin")
        {
            List<Stock> stk = (from s in db.Stocks
                               where s.Qty < s.Item.AlertQty
                               select s).ToList();
            return View(stk);
        }
        else
        {
            List<Stock> stk = (from s in db.Stocks
                               where s.Qty == s.InitialQty
                               select s).ToList();
            return View(stk);
        }
    }
    if (option == "0" && batch != "" && name == "")
    {
        List<Stock> stk = (from s in db.Stocks
                           where s.BatchNo == batch
                           select s).ToList();
        return View(stk);
    }
    if (option == "0" && batch == "" && name != "")
    {
        List<Stock> stk = (from s in db.Stocks
                           where s.Item.Name.StartsWith(""+name+"")
                           select s).ToList();
        return View(stk);
    }
    return View(db.Stocks.ToList());
}

推荐答案

我建议您将关注点分开，并使用一种方法，使您的控制器中的代码像这样简单、美观且可扩展:

I recommend you separate concerns and use an approach that the code in your controller be like this, simple, beautiful and extensible:

public ActionResult Index(ProductSearchModel searchModel)
{
    var business = new ProductBusinessLogic();
    var model = business.GetProducts(searchModel);
    return View(model);
}

优点:

• 您可以根据自己的要求在 ProductSearchModel 中放入任何您需要的东西.
• 您可以根据需求在 GetProducts 中编写任何逻辑.没有限制.
• 如果您添加新的字段或选项进行搜索，您的操作和控制器将保持不变.
• 如果您的搜索逻辑发生变化，您的操作和控制器将保持不变.
• 您可以在需要搜索产品、控制器甚至其他业务逻辑的任何地方重复使用搜索逻辑.
• 有了这样的ProductSearchModel，你可以将它用作ProductSearch局部视图的模型，你可以将DataAnnotations应用到它来增强模型验证并使用 Display 或其他属性帮助 UI 呈现它.
• 您可以在该业务逻辑类中添加与您的产品相关的其他业务逻辑.
• 按照这种方式，您可以拥有一个更有条理的应用程序.

• You can put anything you need in your ProductSearchModel based on your requirements.
• You can write any logic in GetProducts based on requirements. There is no limitation.
• If you add a new field or option to search, your action and controller will remain untouched.
• If the logic of your search changes, your action and controller will remain untouched.
• You can reuse logic of search wherever you need to search on products, in controllers or even in other business logic.
• Having such ProductSearchModel, you can use it as model of ProductSearch partial view and you can apply DataAnnotations to it to enhance the model validation and help UI to render it using Display or other attributes.
• You can add other business logic related to your product in that business logic class.
• Following this way you can have a more organized application.

示例实现:

假设您有一个 Product 类:

public class Product
{
    public int Id { get; set; }
    public int Price { get; set; }
    public string Name { get; set; }
}

您可以创建一个 ProductSearchModel 类并根据它们放置一些您要搜索的字段:

You can create a ProductSearchModel class and put some fields you want to search based on them:

public class ProductSearchModel
{
    public int? Id { get; set; }
    public int? PriceFrom { get; set; }
    public int? PriceTo { get; set; }
    public string Name { get; set; }
}

然后你可以把你的搜索逻辑放在 ProductBusinessLogic 类中:

Then you can put your search logic in ProductBusinessLogic class this way:

public class ProductBusinessLogic
{
    private YourDbContext Context;
    public ProductBusinessLogic()
    {
        Context = new YourDbContext();
    }

    public IQueryable<Product> GetProducts(ProductSearchModel searchModel)
    {
        var result = Context.Products.AsQueryable();
        if (searchModel != null)
        {
            if (searchModel.Id.HasValue)
                result = result.Where(x => x.Id == searchModel.Id);
            if (!string.IsNullOrEmpty(searchModel.Name))
                result = result.Where(x => x.Name.Contains(searchModel.Name));
            if (searchModel.PriceFrom.HasValue)
                result = result.Where(x => x.Price >= searchModel.PriceFrom);
            if (searchModel.PriceTo.HasValue)
                result = result.Where(x => x.Price <= searchModel.PriceTo);
        }
        return result;     
    }
}

然后在你的 ProductController 中你可以这样使用:

Then in your ProductController you can use this way:

public ActionResult Index(ProductSearchModel searchModel)
{
    var business = new ProductBusinessLogic();
    var model = business.GetProducts(searchModel);
    return View(model);
}

重要提示:

在现实世界的实现中，请考虑为您的业务类实现合适的 Dispose 模式，以便在需要时处理数据库上下文.有关更多信息，请查看 实施 Dispose 方法 或 处置模式.

In a real world implementation, please consider implementing a suitable Dispose pattern for your business class to dispose db context when needed. For more information take a look at Implementing a Dispose method or Dispose Pattern.

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