I want to call CsharpFunction
, a C# function in code-behind, from JavaScript. I tried the code below but whether the JavaScript condition is True
or False
, CsharpFunction
was called regardless!
JavaScript code:
if (Javascriptcondition > 0) {
<%CsharpFunction();%>
}
C# code behind:
protected void CsharpFunction()
{
// Notification.show();
}
How do I call a C# function from JavaScript?
This question is related to
javascript
c#
asp.net
code-behind
If you're meaning to make a server call from the client, you should use Ajax - look at something like Jquery and use $.Ajax() or $.getJson() to call the server function, depending on what kind of return you're after or action you want to execute.
.CS File
namespace Csharp
{
public void CsharpFunction()
{
//Code;
}
}
JS code:
function JSFunction() {
<%#ProjectName.Csharp.CsharpFunction()%> ;
}
Note :in JS Function when call your CS page function.... first name of project then name of name space of CS page then function name
Use Blazor http://learn-blazor.com/architecture/interop/
Here's the C#:
namespace BlazorDemo.Client
{
public static class MyCSharpFunctions
{
public static void CsharpFunction()
{
// Notification.show();
}
}
}
Then the Javascript:
const CsharpFunction = Blazor.platform.findMethod(
"BlazorDemo.Client",
"BlazorDemo.Client",
"MyCSharpFunctions",
"CsharpFunction"
);
if (Javascriptcondition > 0) {
Blazor.platform.callMethod(CsharpFunction, null)
}
A modern approach is to use ASP.NET Web API 2 (server-side) with jQuery Ajax (client-side).
Like page methods and ASMX web methods, Web API allows you to write C# code in ASP.NET which can be called from a browser or from anywhere, really!
Here is an example Web API controller, which exposes API methods allowing clients to retrieve details about 1 or all products (in the real world, products would likely be loaded from a database):
public class ProductsController : ApiController
{
Product[] products = new Product[]
{
new Product { Id = 1, Name = "Tomato Soup", Category = "Groceries", Price = 1 },
new Product { Id = 2, Name = "Yo-yo", Category = "Toys", Price = 3.75M },
new Product { Id = 3, Name = "Hammer", Category = "Hardware", Price = 16.99M }
};
[Route("api/products")]
[HttpGet]
public IEnumerable<Product> GetAllProducts()
{
return products;
}
[Route("api/product/{id}")]
[HttpGet]
public IHttpActionResult GetProduct(int id)
{
var product = products.FirstOrDefault((p) => p.Id == id);
if (product == null)
{
return NotFound();
}
return Ok(product);
}
}
The controller uses this example model class:
public class Product
{
public int Id { get; set; }
public string Name { get; set; }
public string Category { get; set; }
public decimal Price { get; set; }
}
Example jQuery Ajax call to get and iterate over a list of products:
$(document).ready(function () {
// Send an AJAX request
$.getJSON("/api/products")
.done(function (data) {
// On success, 'data' contains a list of products.
$.each(data, function (key, item) {
// Add a list item for the product.
$('<li>', { text: formatItem(item) }).appendTo($('#products'));
});
});
});
Not only does this allow you to easily create a modern Web API, you can if you need to get really professional and document it too, using ASP.NET Web API Help Pages and/or Swashbuckle.
Web API can be retro-fitted (added) to an existing ASP.NET Web Forms project. In that case you will need to add routing instructions into the Application_Start
method in the file Global.asax
:
RouteTable.Routes.MapHttpRoute(
name: "DefaultApi",
routeTemplate: "api/{controller}/{id}",
defaults: new { id = System.Web.Http.RouteParameter.Optional }
);
You can't. Javascript runs client side, C# runs server side.
In fact, your server will run all the C# code, generating Javascript. The Javascript then, is run in the browser. As said in the comments, the compiler doesn't know Javascript.
To call the functionality on your server, you'll have to use techniques such as AJAX, as said in the other answers.
Source: Stackoverflow.com