问题
How can I pass in multiple parameters to Get methods in an MVC 6 controller. For example I want to be able to have something like the following.
[Route("api/[controller]")]
public class PersonController : Controller
{
public string Get(int id)
{
}
public string Get(string firstName, string lastName)
{
}
public string Get(string firstName, string lastName, string address)
{
}
}
So I can query like.
api/person?id=1
api/person?firstName=john&lastName=doe
api/person?firstName=john&lastName=doe&address=streetA
回答1:
You also can use this:
// GET api/user/firstname/lastname/address
[HttpGet("{firstName}/{lastName}/{address}")]
public string GetQuery(string id, string firstName, string lastName, string address)
{
return $"{firstName}:{lastName}:{address}";
}
Note: Please refer to metalheart's and metalheart and Mark Hughes for a possibly better approach.
回答2:
Why not using just one controller action?
public string Get(int? id, string firstName, string lastName, string address)
{
if (id.HasValue)
GetById(id);
else if (string.IsNullOrEmpty(address))
GetByName(firstName, lastName);
else
GetByNameAddress(firstName, lastName, address);
}
Another option is to use attribute routing, but then you'd need to have a different URL format:
//api/person/byId?id=1
[HttpGet("byId")]
public string Get(int id)
{
}
//api/person/byName?firstName=a&lastName=b
[HttpGet("byName")]
public string Get(string firstName, string lastName, string address)
{
}
回答3:
To parse the search parameters from the URL, you need to annotate the controller method parameters with [FromQuery], for example:
[Route("api/person")]
public class PersonController : Controller
{
[HttpGet]
public string GetById([FromQuery]int id)
{
}
[HttpGet]
public string GetByName([FromQuery]string firstName, [FromQuery]string lastName)
{
}
[HttpGet]
public string GetByNameAndAddress([FromQuery]string firstName, [FromQuery]string lastName, [FromQuery]string address)
{
}
}
回答4:
I think the easiest way is to simply use AttributeRouting.
[Route("api/YOURCONTROLLER/{paramOne}/{paramTwo}")]
public string Get(int paramOne, int paramTwo)
{
return "The [Route] with multiple params worked";
}
回答5:
To add some more detail about the overloading that you asked about in your comment after another answer, here is a summary. The comments in the ApiController show which action will be called with each GET query:
public class ValuesController : ApiController
{
// EXPLANATION: See the view for the buttons which call these WebApi actions. For WebApi controllers,
// there can only be one action for a given HTTP verb (GET, POST, etc) which has the same method signature, (even if the param names differ) so
// you can't have Get(string height) and Get(string width), but you can have Get(int height) and Get(string width).
// It isn't a particularly good idea to do that, but it is true. The key names in the query string must match the
// parameter names in the action, and the match is NOT case sensitive. This demo app allows you to test each of these
// rules, as follows:
//
// When you send an HTTP GET request with no parameters (/api/values) then the Get() action will be called.
// When you send an HTTP GET request with a height parameter (/api/values?height=5) then the Get(int height) action will be called.
// When you send an HTTP GET request with a width parameter (/api/values?width=8) then the Get(string width) action will be called.
// When you send an HTTP GET request with height and width parameters (/api/values?height=3&width=7) then the
// Get(string height, string width) action will be called.
// When you send an HTTP GET request with a depth parameter (/api/values?depth=2) then the Get() action will be called
// and the depth parameter will be obtained from Request.GetQueryNameValuePairs().
// When you send an HTTP GET request with height and depth parameters (/api/values?height=4&depth=5) then the Get(int height)
// action will be called, and the depth parameter would need to be obtained from Request.GetQueryNameValuePairs().
// When you send an HTTP GET request with width and depth parameters (/api/values?width=3&depth=5) then the Get(string width)
// action will be called, and the depth parameter would need to be obtained from Request.GetQueryNameValuePairs().
// When you send an HTTP GET request with height, width and depth parameters (/api/values?height=7&width=2&depth=9) then the
// Get(string height, string width) action will be called, and the depth parameter would need to be obtained from
// Request.GetQueryNameValuePairs().
// When you send an HTTP GET request with a width parameter, but with the first letter of the parameter capitalized (/api/values?Width=8)
// then the Get(string width) action will be called because the case does NOT matter.
// NOTE: If you were to uncomment the Get(string height) action below, then you would get an error about there already being
// a member named Get with the same parameter types. The same goes for Get(int id).
//
// ANOTHER NOTE: Using the nullable operator (e.g. string? paramName) you can make optional parameters. It would work better to
// demonstrate this in another ApiController, since using nullable params and having a lot of signatures is a recipe
// for confusion.
// GET api/values
public IEnumerable<string> Get()
{
return Request.GetQueryNameValuePairs().Select(pair => "Get() => " + pair.Key + ": " + pair.Value);
//return new string[] { "value1", "value2" };
}
//// GET api/values/5
//public IEnumerable<string> Get(int id)
//{
// return new string[] { "Get(height) => height: " + id };
//}
// GET api/values?height=5
public IEnumerable<string> Get(int height) // int id)
{
return new string[] { "Get(height) => height: " + height };
}
// GET api/values?height=3
public IEnumerable<string> Get(string height)
{
return new string[] { "Get(height) => height: " + height };
}
//// GET api/values?width=3
//public IEnumerable<string> Get(string width)
//{
// return new string[] { "Get(width) => width: " + width };
//}
// GET api/values?height=4&width=3
public IEnumerable<string> Get(string height, string width)
{
return new string[] { "Get(height, width) => height: " + height + ", width: " + width };
}
}
You would only need a single route for this, in case you wondered:
config.Routes.MapHttpRoute(
name: "DefaultApi",
routeTemplate: "api/{controller}/{id}",
defaults: new { id = RouteParameter.Optional }
);
and you could test it all with this MVC view, or something simlar. Yes, I know you aren't supposed to mix JavaScript with markup and I'm not using bootstrap like you would normally, but this is for demo purposes only.
<div class="jumbotron">
<h1>Multiple parameters test</h1>
<p class="lead">Click a link below, which will send an HTTP GET request with parameters to a WebAPI controller.</p>
</div>
<script language="javascript">
function passNothing() {
$.get("/api/values", function (data) { alert(data); });
}
function passHeight(height) {
$.get("/api/values?height=" + height, function (data) { alert(data); });
}
function passWidth(width) {
$.get("/api/values?width=" + width, function (data) { alert(data); });
}
function passHeightAndWidth(height, width) {
$.get("/api/values?height=" + height + "&width=" + width, function (data) { alert(data); });
}
function passDepth(depth) {
$.get("/api/values?depth=" + depth, function (data) { alert(data); });
}
function passHeightAndDepth(height, depth) {
$.get("/api/values?height=" + height + "&depth=" + depth, function (data) { alert(data); });
}
function passWidthAndDepth(width, depth) {
$.get("/api/values?width=" + width + "&depth=" + depth, function (data) { alert(data); });
}
function passHeightWidthAndDepth(height, width, depth) {
$.get("/api/values?height=" + height + "&width=" + width + "&depth=" + depth, function (data) { alert(data); });
}
function passWidthWithPascalCase(width) {
$.get("/api/values?Width=" + width, function (data) { alert(data); });
}
</script>
<div class="row">
<button class="btn" onclick="passNothing();">Pass Nothing</button>
<button class="btn" onclick="passHeight(5);">Pass Height of 5</button>
<button class="btn" onclick="passWidth(8);">Pass Width of 8</button>
<button class="btn" onclick="passHeightAndWidth(3, 7);">Pass Height of 3 and Width of 7</button>
<button class="btn" onclick="passDepth(2);">Pass Depth of 2</button>
<button class="btn" onclick="passHeightAndDepth(4, 5);">Pass Height of 4 and Depth of 5</button>
<button class="btn" onclick="passWidthAndDepth(3, 5);">Pass Width of 3 and Depth of 5</button>
<button class="btn" onclick="passHeightWidthAndDepth(7, 2, 9);">Pass Height of 7, Width of 2 and Depth of 9</button>
<button class="btn" onclick="passHeightWidthAndDepth(7, 2, 9);">Pass Height of 7, Width of 2 and Depth of 9</button>
<button class="btn" onclick="passWidthWithPascalCase(8);">Pass Width of 8, but with Pascal case</button>
</div>
回答6:
NB-I removed FromURI .Still I can pass value from URL and get result.If anyone knows benfifts using fromuri let me know
回答7:
You can simply do the following:
[HttpGet]
public async Task<IActionResult> GetAsync()
{
string queryString = Request.QueryString.ToString().ToLower();
return Ok(await DoMagic.GetAuthorizationTokenAsync(new Uri($"https://someurl.com/token-endpoint{queryString}")));
}
If you need to access each element separately, simply refer to Request.Query.
回答8:
public HttpResponseMessage Get(int id,string numb)
{
using (MarketEntities entities = new MarketEntities())
{
var ent= entities.Api_For_Test.FirstOrDefault(e => e.ID == id && e.IDNO.ToString()== numb);
if (ent != null)
{
return Request.CreateResponse(HttpStatusCode.OK, ent);
}
else
{
return Request.CreateErrorResponse(HttpStatusCode.NotFound, "Applicant with ID " + id.ToString() + " not found in the system");
}
}
}
来源：https://stackoverflow.com/questions/36280947/how-to-pass-multiple-parameters-to-a-get-method-in-asp-net-core