C# HttpClient.PostAsJsonAsync不工作或在调试模式下出现任何错误

我在MVC中使用Web API时遇到了一些问题，不确定是什么原因造成的，但在调试模式下它不会抛出任何异常或错误，请有人帮助解决这个问题

代码如下：

MVC控制器调用：

PortalLogonCheckParams credParams = new PortalLogonCheckParams() {SecurityLogonLogonId = model.UserName, SecurityLogonPassword = model.Password};

SecurityLogon secureLogon = new SecurityLogon();

var result = secureLogon.checkCredentials(credParams);

public async Task <IEnumerable<PortalLogon>> checkCredentials(PortalLogonCheckParams credParams)
{
    using (var client = new HttpClient())
    {
        client.BaseAddress = new Uri("http://localhost:50793/");
        client.DefaultRequestHeaders.Accept.Clear();
        client.DefaultRequestHeaders.Accept.Add(new MediaTypeWithQualityHeaderValue("application/json"));

        // Check Credentials

        //Following call fails

        HttpResponseMessage response = await client.PostAsJsonAsync("api/chkPortalLogin", credParams);  


        if (response.IsSuccessStatusCode)
        {
            IEnumerable<PortalLogon> logonList = await response.Content.ReadAsAsync<IEnumerable<PortalLogon>>();
            return logonList;
        }
        else return null;
    }

}

[HttpPost]
public IHttpActionResult chkPortalLogin([FromBody] PortalLogonCheckParams LogonParams)
{

    List<Mod_chkPortalSecurityLogon> securityLogon = null;

    String strDBName = "";

    //Set the database identifier        
    strDBName = "Mod";

    //Retrieve the Logon object
    using (DataConnection connection = new DataConnection(strDBName))
    {
        //Retrieve the list object
        securityLogon = new Persistant_Mod_chkPortalSecurityLogon().findBy_Search(connection.Connection, LogonParams.SecurityLogonLogonId, LogonParams.SecurityLogonPassword);
    }

    AutoMapper.Mapper.CreateMap<Mod_chkPortalSecurityLogon, PortalLogon>();

    IEnumerable<PortalLogon> securityLogonNew = AutoMapper.Mapper.Map<IEnumerable<Mod_chkPortalSecurityLogon>, IEnumerable<PortalLogon>>(securityLogon);


    return Ok(securityLogonNew);

}

数据访问对象方法：

PortalLogonCheckParams credParams = new PortalLogonCheckParams() {SecurityLogonLogonId = model.UserName, SecurityLogonPassword = model.Password};

SecurityLogon secureLogon = new SecurityLogon();

var result = secureLogon.checkCredentials(credParams);

public async Task <IEnumerable<PortalLogon>> checkCredentials(PortalLogonCheckParams credParams)
{
    using (var client = new HttpClient())
    {
        client.BaseAddress = new Uri("http://localhost:50793/");
        client.DefaultRequestHeaders.Accept.Clear();
        client.DefaultRequestHeaders.Accept.Add(new MediaTypeWithQualityHeaderValue("application/json"));

        // Check Credentials

        //Following call fails

        HttpResponseMessage response = await client.PostAsJsonAsync("api/chkPortalLogin", credParams);  


        if (response.IsSuccessStatusCode)
        {
            IEnumerable<PortalLogon> logonList = await response.Content.ReadAsAsync<IEnumerable<PortalLogon>>();
            return logonList;
        }
        else return null;
    }

}

[HttpPost]
public IHttpActionResult chkPortalLogin([FromBody] PortalLogonCheckParams LogonParams)
{

    List<Mod_chkPortalSecurityLogon> securityLogon = null;

    String strDBName = "";

    //Set the database identifier        
    strDBName = "Mod";

    //Retrieve the Logon object
    using (DataConnection connection = new DataConnection(strDBName))
    {
        //Retrieve the list object
        securityLogon = new Persistant_Mod_chkPortalSecurityLogon().findBy_Search(connection.Connection, LogonParams.SecurityLogonLogonId, LogonParams.SecurityLogonPassword);
    }

    AutoMapper.Mapper.CreateMap<Mod_chkPortalSecurityLogon, PortalLogon>();

    IEnumerable<PortalLogon> securityLogonNew = AutoMapper.Mapper.Map<IEnumerable<Mod_chkPortalSecurityLogon>, IEnumerable<PortalLogon>>(securityLogon);


    return Ok(securityLogonNew);

}

公共异步任务检查凭据（PortalLogonCheckParams credParams）
{
使用（var client=new HttpClient（））
{
client.BaseAddress=新Uri（“http://localhost:50793/");
client.DefaultRequestHeaders.Accept.Clear（）；
client.DefaultRequestHeaders.Accept.Add（新的MediaTypeWithQualityHeaderValue（“应用程序/json”）；
//检查凭证
//以下呼叫失败
HttpResponseMessage response=wait client.postsJSONASync（“api/chkPortalLogin”，credParams）；
if（响应。IsSuccessStatusCode）
{
IEnumerable logonList=wait response.Content.ReadAsAsync（）；
返回登录列表；
}
否则返回null；
}
}

Web API:

PortalLogonCheckParams credParams = new PortalLogonCheckParams() {SecurityLogonLogonId = model.UserName, SecurityLogonPassword = model.Password};

SecurityLogon secureLogon = new SecurityLogon();

var result = secureLogon.checkCredentials(credParams);

public async Task <IEnumerable<PortalLogon>> checkCredentials(PortalLogonCheckParams credParams)
{
    using (var client = new HttpClient())
    {
        client.BaseAddress = new Uri("http://localhost:50793/");
        client.DefaultRequestHeaders.Accept.Clear();
        client.DefaultRequestHeaders.Accept.Add(new MediaTypeWithQualityHeaderValue("application/json"));

        // Check Credentials

        //Following call fails

        HttpResponseMessage response = await client.PostAsJsonAsync("api/chkPortalLogin", credParams);  


        if (response.IsSuccessStatusCode)
        {
            IEnumerable<PortalLogon> logonList = await response.Content.ReadAsAsync<IEnumerable<PortalLogon>>();
            return logonList;
        }
        else return null;
    }

}

[HttpPost]
public IHttpActionResult chkPortalLogin([FromBody] PortalLogonCheckParams LogonParams)
{

    List<Mod_chkPortalSecurityLogon> securityLogon = null;

    String strDBName = "";

    //Set the database identifier        
    strDBName = "Mod";

    //Retrieve the Logon object
    using (DataConnection connection = new DataConnection(strDBName))
    {
        //Retrieve the list object
        securityLogon = new Persistant_Mod_chkPortalSecurityLogon().findBy_Search(connection.Connection, LogonParams.SecurityLogonLogonId, LogonParams.SecurityLogonPassword);
    }

    AutoMapper.Mapper.CreateMap<Mod_chkPortalSecurityLogon, PortalLogon>();

    IEnumerable<PortalLogon> securityLogonNew = AutoMapper.Mapper.Map<IEnumerable<Mod_chkPortalSecurityLogon>, IEnumerable<PortalLogon>>(securityLogon);


    return Ok(securityLogonNew);

}

[HttpPost]
public IHttpActionResult chkPortalLogin（[FromBody]PortalLogonCheckParams LogonParams）
{
List securityLogon=null；
字符串strDBName=“”；
//设置数据库标识符
strDBName=“Mod”；
//检索登录对象
使用（DataConnection=newdataconnection（strDBName））
{
//检索列表对象
securityLogon=new Persistant_Mod_chkPortalSecurityLogon（）。通过搜索查找（connection.connection，LogonParams.SecurityLogonLogonId，LogonParams.SecurityLogonPassword）；
}
AutoMapper.Mapper.CreateMap（）；
IEnumerable securityLogonNew=AutoMapper.Mapper.Map（securityLogon）；
返回Ok（securityLogonNew）；
}

您需要从参数中删除

[FromBody]

属性

要强制Web API从请求正文读取简单类型，请添加 参数的[FromBody]属性：

public HttpResponseMessage Post([FromBody] string name) { ... }

在本例中，Web API将使用媒体类型格式化程序来读取 请求正文中名称的值。下面是一个示例客户端 请求

POST http://localhost:5076/api/values HTTP/1.1
User-Agent: Fiddler
Host: localhost:5076
Content-Type: application/json
Content-Length: 7

"Alice"

当参数具有[FromBody]时，Web API使用内容类型标头 选择格式化程序。在本例中，内容类型为 “application/json”，请求主体是一个原始json字符串（不是 JSON对象）

最多允许从消息体读取一个参数

---

您是否尝试过通过fiddler或SOAP UI进行调用，如果是的话，响应代码是什么？您所说的“不工作”是什么意思？哪里出了问题？您希望发生什么？从参数中删除

[FromBody]

属性。