如何将json POST数据作为对象传递给Web API方法？

曾经终败给现在 2022-11-29 03:20 169阅读 0赞

本文翻译自：[How to pass json POST data to Web API method as an object?][How to pass json POST data to Web API method as an object]

*ASP.NET MVC4 Web API application defines post method to save customer.* **ASP.NET MVC4 Web API应用程序定义了保存客户的post方法。** *Customer is passed in json format in POST request body.* **客户在POST请求正文中以json格式传递。** *Customer parameter in post method contains null values for properties.* **post方法中的customer参数包含属性的空值。**

*How to fix this so that posted data will passed as customer object ?* **如何解决这个问题，以便发布的数据作为客户对象传递？**

*If possible Content-Type: application/x-www-form-urlencoded should used since I dont know how to change it in javascript method which posts form.* **如果可能的话Content-Type：application / x-www-form-urlencoded应该使用，因为我不知道如何在发布表单的javascript方法中更改它。**

*Controller:* **控制器：**

public class CustomersController : ApiController {
    
      public object Post([FromBody] Customer customer)
            {
                return Request.CreateResponse(HttpStatusCode.OK,
                new
                {
                    customer = customer
                });
            }
        }
    }
    
    public class Customer
        {
            public string company_name { get; set; }
            public string contact_name { get; set; }
         }

*Request:* **请求：**

POST http://localhost:52216/api/customers HTTP/1.1
    Accept: application/json, text/javascript, */*; q=0.01
    X-Requested-With: XMLHttpRequest
    Content-Type: application/x-www-form-urlencoded; charset=UTF-8
    
    {"contact_name":"sdfsd","company_name":"ssssd"}

--------------------

### \#1楼 ###

参考：[https://stackoom.com/question/1mRKx/如何将json-POST数据作为对象传递给Web-API方法][https_stackoom.com_question_1mRKx_json-POST_Web-API]

--------------------

### \#2楼 ###

***EDIT** : 31/10/2017* **编辑 ：31/10/2017**

*The same code/approach will work for **Asp.Net Core 2.0** as well.* **相同的代码/方法也适用于Asp.Net Core 2.0 。** *The major difference is, In asp.net core, both web api controllers and Mvc controllers are merged together to single controller model.* **主要区别在于，在asp.net核心中，web api控制器和Mvc控制器都合并到单个控制器模型中。** *So your return type might be `IActionResult` or one of it's implementation (Ex : `OkObjectResult` )* **所以你的返回类型可能是`IActionResult`或其中一个实现（例如： `OkObjectResult` ）**

--------------------

*Use* **使用**

contentType:"application/json"

*You need to use `JSON.stringify` method to convert it to JSON string when you send it,* **发送时需要使用`JSON.stringify`方法将其转换为JSON字符串，**

*And the model binder will bind the json data to your class object.* **模型绑定器将json数据绑定到您的类对象。**

*The below code will work fine (tested)* **以下代码将正常工作（测试）**

$(function () {
        var customer = {contact_name :"Scott",company_name:"HP"};
        $.ajax({
            type: "POST",
            data :JSON.stringify(customer),
            url: "api/Customer",
            contentType: "application/json"
        });
    });

***Result*** **结果**

![在此输入图像描述][69yQt.png]

*`contentType` property tells the server that we are sending the data in JSON format.* **`contentType`属性告诉服务器我们正在以JSON格式发送数据。** *Since we sent a JSON data structure,model binding will happen properly.* **由于我们发送了JSON数据结构，因此模型绑定将正确发生。**

*If you inspect the ajax request's headers, you can see that the `Content-Type` value is set as `application/json` .* **如果检查ajax请求的标头，则可以看到`Content-Type`值设置为`application/json` 。**

*If you do not specify contentType explicitly, It will use the default content type which is `application/x-www-form-urlencoded;`* **如果您没有明确指定contentType，它将使用默认的内容类型，即`application/x-www-form-urlencoded;`**

--------------------

*Edit on Nov 2015 to address other possible issues raised in comments* ***2015年11月编辑，以解决评论中提出的其他可能问题***

## *Posting a complex object* **发布复杂对象** ##

*Let's say you have a complex view model class as your web api action method parameter like this* **假设你有一个复杂的视图模型类作为你的web api动作方法参数**

public class CreateUserViewModel
    {
       public int Id {set;get;}
       public string Name {set;get;}  
       public List<TagViewModel> Tags {set;get;}
    }
    public class TagViewModel
    {
      public int Id {set;get;}
      public string Code {set;get;}
    }

*and your web api end point is like* **和你的web api终点就像**

public class ProductController : Controller
    {
        [HttpPost]
        public CreateUserViewMode Save([FromBody] CreateUserViewModel m)
        {
            // I am just returning the posted model as it is. 
            // You may do other stuff and return different response.
            // Ex : missileService.LaunchMissile(m);
            return m;
        }
    }

*At the time of this writing, ASP.NET MVC 6 is the latest stable version and in MVC6, Both Web api controllers and MVC controllers are inheriting from `Microsoft.AspNet.Mvc.Controller` base class.* ***在撰写本文时，ASP.NET MVC 6是最新的稳定版本，在MVC6中，Web api控制器和MVC控制器都继承自`Microsoft.AspNet.Mvc.Controller`基类。***

*To send data to the method from client side, the below code should work fine* **要从客户端向方法发送数据，下面的代码应该可以正常工作**

//Build an object which matches the structure of our view model class
    var model = {
        Name: "Shyju",
        Id: 123,
        Tags: [{ Id: 12, Code: "C" }, { Id: 33, Code: "Swift" }]
    };
    
    $.ajax({
        type: "POST",
        data: JSON.stringify(model),
        url: "../product/save",
        contentType: "application/json"
    }).done(function(res) {       
        console.log('res', res);
        // Do something with the result :)
    });

## *Model binding works for some properties, but not all !* **模型绑定适用于某些属性，但不是全部！** *Why ?* **为什么？** ##

*If you do not decorate the web api method parameter with `[FromBody]` attribute* **如果不使用`[FromBody]`属性修饰web api方法参数**

[HttpPost]
    public CreateUserViewModel Save(CreateUserViewModel m)
    {
        return m;
    }

*And send the model(raw javascript object, not in JSON format) without specifying the contentType property value* **并且在不指定contentType属性值的情况下发送模型（原始javascript对象，而不是JSON格式）**

$.ajax({
        type: "POST",
        data: model,
        url: "../product/save"
    }).done(function (res) {
         console.log('res', res);
    });

*Model binding will work for the flat properties on the model, not the properties where the type is complex/another type.* **模型绑定适用于模型上的平面属性，而不适用于类型复杂/其他类型的属性。** *In our case, `Id` and `Name` properties will be properly bound to the parameter `m` , But the `Tags` property will be an empty list.* **在我们的例子中， `Id`和`Name`属性将正确绑定到参数`m` ，但`Tags`属性将是一个空列表。**

*The same problem will occur if you are using the short version, `$.post` which will use the default Content-Type when sending the request.* **如果您使用的是简短版本`$.post` ，在发送请求时将使用默认的Content-Type，则会出现同样的问题。**

$.post("../product/save", model, function (res) {
        //res contains the markup returned by the partial view
        console.log('res', res);
    });

--------------------

### \#3楼 ###

*Working with POST in webapi can be tricky!* **在webapi中使用POST可能很棘手！** *Would like to add to the already correct answer..* **想补充已经正确的答案..**

*Will focus specifically on POST as dealing with GET is trivial.* **将专注于POST，因为处理GET是微不足道的。** *I don't think many would be searching around for resolving an issue with GET with webapis.* **我不认为很多人会用webapis解决GET问题。** *Anyways..* **无论如何..**

*If your question is - In MVC Web Api, how to- - Use custom action method names other than the generic HTTP verbs?* **如果您的问题是 - 在MVC Web Api中，如何 - 使用除通用HTTP谓词之外的自定义操作方法名称？** *- Perform multiple posts?*  **- 执行多个帖子？** *- Post multiple simple types?*  **- 发布多个简单类型？** *- Post complex types via jQuery?*  **- 通过jQuery发布复杂类型？**

*Then the following solutions may help:* **那么以下解决方案可能有所帮助**

*First, to use **Custom** Action Methods in Web API, add a web api route as:* **首先，要在Web API中使用自定义操作方法，请将web api路由添加为：**

public static void Register(HttpConfiguration config)
    {
        config.Routes.MapHttpRoute(
            name: "ActionApi",
            routeTemplate: "api/{controller}/{action}");
    }

*And then you may create action methods like:* **然后你可以创建动作方法，如：**

[HttpPost]
    public string TestMethod([FromBody]string value)
    {
        return "Hello from http post web api controller: " + value;
    }

*Now, fire the following jQuery from your browser console* **现在，从浏览器控制台激发以下jQuery**

$.ajax({
        type: 'POST',
        url: 'http://localhost:33649/api/TestApi/TestMethod',
        data: {'':'hello'},
        contentType: 'application/x-www-form-urlencoded',
        dataType: 'json',
        success: function(data){ console.log(data) }
    });

*Second, to **perform multiple posts** , It is simple, create multiple action methods and decorate with the \[HttpPost\] attrib.* **第二，要执行多个帖子 ，很简单，创建多个动作方法并用\[HttpPost\] attrib进行装饰。** *Use the \[ActionName("MyAction")\] to assign custom names, etc. Will come to jQuery in the fourth point below* **使用\[ActionName（“MyAction”）\]分配自定义名称等。将在下面的第四点讨论jQuery**

*Third, First of all, posting multiple **SIMPLE** types in a single action is not possible.* **第三，首先，不可能在单个动作中发布多个SIMPLE类型。** *Moreover, there is a **special format** to post even a **single simple type** (apart from passing the parameter in the query string or REST style).* **此外，有一种特殊的格式可以发布一个简单的类型 （除了在查询字符串或REST样式中传递参数）。** *This was the point that had me banging my head with Rest Clients (like Fiddler and Chrome's Advanced REST client extension) and hunting around the web for almost 5 hours when eventually, the following URL proved to be of help.* **这就是让我与Rest Clients（如Fiddler和Chrome的高级REST客户端扩展）一起敲打头脑并在网上狩猎近5个小时的时间点，最终，以下网址被证明是有帮助的。** *Will quote the relevant content for the link might turn dead!* **会引用该链接的相关内容可能会变死！**

Content-Type: application/x-www-form-urlencoded
    in the request header and add a = before the JSON statement:
    ={"Name":"Turbo Tina","Email":"na@Turbo.Tina"}

*PS: Noticed the peculiar syntax ?* **PS：注意到*特殊的语法* ？**

*[http://forums.asp.net/t/1883467.aspx?The+received+value+is+null+when+I+try+to+Post+to+my+Web+Api][http_forums.asp.net_t_1883467.aspx_The_received_value_is_null_when_I_try_to_Post_to_my_Web_Api]* **[http://forums.asp.net/t/1883467.aspx?The+received+value+is+null+when+I+try+to+Post+to+my+Web+Api][http_forums.asp.net_t_1883467.aspx_The_received_value_is_null_when_I_try_to_Post_to_my_Web_Api]**

*Anyways, let us get over that story.* **无论如何，让我们克服那个故事。** *Moving on:* **继续：**

*Fourth, **posting complex types** via jQuery, ofcourse, $.ajax() is going to promptly come in the role:* **第四，通过jQuery，ofcourse，$ .ajax（） 发布复杂类型将立即发挥作用：**

*Let us say the action method accepts a Person object which has an id and a name.* **我们假设action方法接受一个具有id和name的Person对象。** *So, from javascript:* **所以，从javascript：**

var person = { PersonId:1, Name:"James" }
    $.ajax({
        type: 'POST',
        url: 'http://mydomain/api/TestApi/TestMethod',
        data: JSON.stringify(person),
        contentType: 'application/json; charset=utf-8',
        dataType: 'json',
        success: function(data){ console.log(data) }
    });

*And the action will look like:* **行动将如下所示：**

[HttpPost]
    public string TestMethod(Person person)
    {
        return "Hello from http post web api controller: " + person.Name;
    }

*All of the above, worked for me!!* **以上所有，为我工作!!** *Cheers!* **干杯!**

--------------------

### \#4楼 ###

*I've just been playing with this and discovered a rather odd result.* **我刚刚玩这个并发现了一个相当奇怪的结果。** *Say you have public properties on your class in C\# like this:* **假设您在C＃中拥有公共属性，如下所示：**

public class Customer
    {
        public string contact_name;
        public string company_name;
    }

*then you must do the JSON.stringify trick as suggested by Shyju and call it like this:* **然后你必须按照Shyju的建议做JSON.stringify技巧，并像这样调用它：**

var customer = {contact_name :"Scott",company_name:"HP"};
    $.ajax({
        type: "POST",
        data :JSON.stringify(customer),
        url: "api/Customer",
        contentType: "application/json"
    });

*However, if you define getters and setters on your class like this:* **但是，如果您在类上定义getter和setter，如下所示：**

public class Customer
    {
        public string contact_name { get; set; }
        public string company_name { get; set; }
    }

*then you can call it much more simply:* **然后你可以更简单地调用它：**

$.ajax({
        type: "POST",
        data :customer,
        url: "api/Customer"
    });

*This uses the HTTP header:* **这使用HTTP标头：**

Content-Type:application/x-www-form-urlencoded

*I'm not quite sure what's happening here but it looks like a bug (feature?) in the framework.* **我不太确定这里发生了什么，但它看起来像框架中的一个错误（功能？）。** *Presumably the different binding methods are calling different "adapters", and while the adapter for application/json one works with public properties, the one for form encoded data doesn't.* **据推测，不同的绑定方法调用不同的“适配器”，而应用程序/ json的适配器使用公共属性，而表单编码数据的适配器则不能。**

*I have no idea which would be considered best practice though.* **我不知道哪个被认为是最好的做法。**

--------------------

### \#5楼 ###

*Use the **JSON.stringify()** to get the string in JSON format, ensure that while making the AJAX call you pass below mentioned attributes:* **使用JSON.stringify（）以JSON格式获取字符串，确保在进行AJAX调用时传递下面提到的属性：**

*  *contentType: 'application/json'* **contentType：'application / json'**
 *  *dataType: 'json'* **dataType：'json'**

*Below is the give jquery code to make ajax post call to asp.net web api:* **下面是给jQuery的代码来调用asp.net web api的ajax：**

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### \#6楼 ###

*Make sure that your WebAPI service is expecting a strongly typed object with a structure that matches the JSON that you are passing.* **确保您的WebAPI服务期望一个强类型对象，其结构与您传递的JSON相匹配。** *And make sure that you stringify the JSON that you are POSTing.* **并确保您对要发布的JSON进行字符串化。**

*Here is my JavaScript (using AngluarJS):* **这是我的JavaScript（使用AngluarJS）：**

$scope.updateUserActivity = function (_objuserActivity) {
            $http
            ({
                method: 'post',
                url: 'your url here',
                headers: { 'Content-Type': 'application/json'},
                data: JSON.stringify(_objuserActivity)
            })
            .then(function (response)
            {
                alert("success");
            })
            .catch(function (response)
            {
                alert("failure");
            })
            .finally(function ()
            {
            });

*And here is my WebAPI Controller:* **这是我的WebAPI控制器：**

[HttpPost]
    [AcceptVerbs("POST")]
    public string POSTMe([FromBody]Models.UserActivity _activity)
    {
        return "hello";
    }

[How to pass json POST data to Web API method as an object]: https://oldbug.net/q/1mRKx/How-to-pass-json-POST-data-to-Web-API-method-as-an-object
[https_stackoom.com_question_1mRKx_json-POST_Web-API]: https://stackoom.com/question/1mRKx/%E5%A6%82%E4%BD%95%E5%B0%86json-POST%E6%95%B0%E6%8D%AE%E4%BD%9C%E4%B8%BA%E5%AF%B9%E8%B1%A1%E4%BC%A0%E9%80%92%E7%BB%99Web-API%E6%96%B9%E6%B3%95
[69yQt.png]: https://i.stack.imgur.com/69yQt.png
[http_forums.asp.net_t_1883467.aspx_The_received_value_is_null_when_I_try_to_Post_to_my_Web_Api]: http://forums.asp.net/t/1883467.aspx?The+received+value+is+null+when+I+try+to+Post+to+my+Web+Api