Để thêm một số chi tiết hơn về tình trạng quá tải mà bạn đã hỏi trong nhận xét của mình sau một câu trả lời khác, đây là bản tóm tắt. Các nhận xét trong ApiControllerchương trình hiển thị hành động nào sẽ được gọi với mỗi GETtruy vấn:
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 };
}
}
Bạn sẽ chỉ cần một tuyến đường duy nhất cho việc này, trong trường hợp bạn tự hỏi:
config.Routes.MapHttpRoute(
name: "DefaultApi",
routeTemplate: "api/{controller}/{id}",
defaults: new { id = RouteParameter.Optional }
);
và bạn có thể kiểm tra tất cả bằng chế độ xem MVC này hoặc một cái gì đó mô phỏng. Có, tôi biết bạn không nên kết hợp JavaScript với đánh dấu và tôi không sử dụng bootstrap như bạn thường làm, nhưng điều này chỉ dành cho mục đích demo.
<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>
