.NET Core 自定义模型绑定器调用默认模型绑定器

Posted 2023-02-15

【中文标题】.NET Core 自定义模型绑定器调用默认模型绑定器

【英文标题】：.NET Core Custom model binder call default model binder

【发布时间】：2018-08-22 09:55:43

【问题描述】：

我正在尝试在 .NET Core 中实现一些将小数四舍五入到小数点后两位的中间件。所有其他映射都可以像现在通过ComplexTypeModelBinder 那样工作。我曾尝试在我之前调用该绑定器或从它继承，但最终模型在碰到控制器时只是为空。

基本上我追求的功能与此处询问的功能相同：Call Default Model Binder from a Custom Model Binder?，但适用于 .NET 核心。

【问题讨论】：

请贴一些代码

将其作为第一个模型活页夹插入ModelBinders.Binders.Insert(typeof(Decimal), new DateTimeModelBinder(), 0);

我认为正确的答案，或接近它，将是使用 DI 并注入您需要的众多粘合剂之一：github.com/aspnet/AspNetCore/tree/master/src/Mvc/Mvc.Core/src/…

【参考方案1】：

public class JqGridModelBinder : IModelBinder

    public Task BindModelAsync(ModelBindingContext bindingContext)
    
        if (bindingContext == null)
        
            throw new ArgumentNullException(nameof(bindingContext));
        

        var request = bindingContext?.ActionContext?.HttpContext?.Request;

        var param = new JqGridParam
        
            isSearch = bool.Parse(request.Query["_search"]),
            pageIndex = int.Parse(request.Query["page"]),
            pageSize = int.Parse(request.Query["rows"]),
            sortColumn = request.Query["sidx"].ToString(),
            sortOrder = request.Query["sord"].ToString(),
            id = request.Query["id"].ToString(),
            param = request.Query["oper"].ToString(),
            editOper = request.Query["edit"].ToString(),
            addOper = request.Query["add"].ToString(),
            delOper = request.Query["del"].ToString(),
            @where = JqGridFilter.Create(request.Query["filters"]),
            //operation = (OPERATION)System.Enum.Parse(typeof(OPERATION), request.Query["oper"]=="null" ? "none": request.Query["oper"].ToString())
        ;
        bindingContext.Result = ModelBindingResult.Success(param);

        return Task.CompletedTask;
    

【讨论】：

为您的代码写一些描述并正确格式化代码。

【参考方案2】：

public enum OPERATION
    
        none,
        add,
        del,
        edit,
        excel
    
    [ModelBinder(BinderType = typeof(JqGridModelBinder))]
    public class JqGridParam
    
        [BindRequired]
        public int pageIndex  get; set; 
        [BindRequired]
        public int pageSize  get; set; 
        [BindRequired]
        public string sortColumn  get; set; 
        [BindRequired]
        public string sortOrder  get; set; 
        [BindRequired]
        public bool isSearch  get; set; 
        [BindRequired]
        public string id  get; set; 
        [BindRequired]
        public string param  get; set; 
        [BindRequired]
        public string editOper  get; set; 
        [BindRequired]
        public string addOper  get; set; 
        [BindRequired]
        public string delOper  get; set; 
        [BindRequired]
        public JqGridFilter where  get; set; 
        [BindRequired]
        public OPERATION operation  get; set; 

    

    [DataContract]
    public class JqGridFilter
    
        [DataMember]
        public string groupOp  get; set; 

        [DataMember]
        public Rule[] rules  get; set; 

        public static JqGridFilter Create(string jsonData)
        
            try
            
                var serializer = new DataContractJsonSerializer(typeof(JqGridFilter));
                //System.IO.StringReader reader = new System.IO.StringReader(jsonData);
                System.IO.MemoryStream ms = new System.IO.MemoryStream(Encoding.Default.GetBytes(jsonData));
                return serializer.ReadObject(ms) as JqGridFilter;
            
            catch
            
                return null;
            
        
    

    [DataContract]
    public class Rule
    
        [DataMember]
        public string field  get; set; 

        [DataMember]
        public string op  get; set; 

        [DataMember]
        public string data  get; set;