c# - WebApi - 从 Uri 和 Body 绑定(bind)

Question

是否可以同时从 Uri 和 Body 绑定(bind)一个模型？

例如，给定以下内容:

routes.MapHttpRoute(
    name: "API Default",
    routeTemplate: "api/{controller}/{id}",
    defaults: new { id = RouteParameter.Optional }
);

public class ProductsController : ApiController
{
    public HttpResponseMessage Put(UpdateProduct model)
    {

    }
}

public class UpdateProduct 
{
    int Id { get; set;}
    string Name { get; set; }
}

是否可以创建自定义 Binder 以便PUT

/api/products/1

使用 JSON 正文:

{
    "Name": "Product Name"
}

将导致 UpdateProduct 模型填充有 Id = 1 和 Name = "Product Name"？

更新

我知道我可以将 Action 签名更改为

public HttpResponseMessage Put(int id, UpdateProduct model)
{

}

但是正如问题中所述，我特别想绑定(bind)到单个模型对象

我也把这个问题发到了WebApi Codeplex discussion forum

Answer 1

这是 odyth 答案的改进版本:

1. 也适用于无形体请求，并且
2. 除了从路由值中获取参数外，还从查询字符串中获取参数。

为简洁起见，我只发布了 ExecuteBindingAsyncCore 方法和一个新的辅助方法，该类的其余部分是相同的。

private async Task ExecuteBindingAsyncCore(ModelMetadataProvider metadataProvider, HttpActionContext actionContext,
        HttpParameterDescriptor paramFromBody, Type type, HttpRequestMessage request, IFormatterLogger formatterLogger,
        CancellationToken cancellationToken)
{
    var model = await ReadContentAsync(request, type, Formatters, formatterLogger, cancellationToken);

    if(model == null) model = Activator.CreateInstance(type);

    var routeDataValues = actionContext.ControllerContext.RouteData.Values;
    var routeParams = routeDataValues.Except(routeDataValues.Where(v => v.Key == "controller"));
    var queryStringParams = new Dictionary<string, object>(QueryStringValues(request));
    var allUriParams = routeParams.Union(queryStringParams).ToDictionary(pair => pair.Key, pair => pair.Value);

    foreach(var key in allUriParams.Keys) {
        var prop = type.GetProperty(key, BindingFlags.IgnoreCase | BindingFlags.Instance | BindingFlags.Public);
        if(prop == null) {
            continue;
        }
        var descriptor = TypeDescriptor.GetConverter(prop.PropertyType);
        if(descriptor.CanConvertFrom(typeof(string))) {
            prop.SetValue(model, descriptor.ConvertFromString(allUriParams[key] as string));
        }
    }

    // Set the merged model in the context
    SetValue(actionContext, model);

    if(BodyModelValidator != null) {
        BodyModelValidator.Validate(model, type, metadataProvider, actionContext, paramFromBody.ParameterName);
    }
}

private static IDictionary<string, object> QueryStringValues(HttpRequestMessage request)
{
    var queryString = string.Join(string.Empty, request.RequestUri.ToString().Split('?').Skip(1));
    var queryStringValues = System.Web.HttpUtility.ParseQueryString(queryString);
    return queryStringValues.Cast<string>().ToDictionary(x => x, x => (object)queryStringValues[x]);
}