Pass C# ASP.NET array to Javascript array

user_382906 0
Viewed 110605

Does anyone know how to pass a C# ASP.NET array to a JavaScript array? Sample code will also be nice.

Sorry if I was vague earlier guys. The question is actually quite simple. Let's say for simplicity that in my aspx.cs file I declare:

int [] numbers = new int[5];

Now I want to pass numbers to the client side and use the data in the array within JavaScript . How would I do this?

asp.net javascript c#
9 Answers

Here is another alternative solution. You can use ClientScriptManager Page.ClientScript.RegisterArrayDeclaration. Here is an example for chart data.

var page = HttpContext.Current.CurrentHandler as Page;

_data = "[Date.UTC(2018, 9, 29, 0, 3), parseFloat(21.84)]
         ,[Date.UTC(2018, 9, 29, 0, 13), parseFloat(21.84)]
         ,[Date.UTC(2018, 9, 29, 0, 23), parseFloat(21.83)]
         ,[Date.UTC(2018, 9, 29, 0, 33), parseFloat(21.83)]";
page.ClientScript.RegisterArrayDeclaration("chartdata0", _data);

This code creates an array on the client side

var chartdata0 = new Array([Date.UTC(2018, 9, 29, 0, 3), parseFloat(21.84)]
             ,[Date.UTC(2018, 9, 29, 0, 13), parseFloat(21.84)]
             ,[Date.UTC(2018, 9, 29, 0, 23), parseFloat(21.83)]
             ,[Date.UTC(2018, 9, 29, 0, 33), parseFloat(21.83)]);

See the following article

https://docs.microsoft.com/en-us/dotnet/api/system.web.ui.clientscriptmanager.registerarraydeclaration?view=netframework-4.8

This solution has an issue with bigger arrays on chrome 64 browser including "Version 78.0.3904.70 (Official Build) (64-bit)". You may get "Uncaught RangeError: Maximum call stack size exceeded". However it is working with IE11, Microsoft Edge, and FireFox.

user_49144090

Simple

The array of integers is quite simple to pass. However this solution works for more complex data as well. In your model:

public int[] Numbers => new int[5];

In your view:

numbers = @(new HtmlString(JsonSerializer.Serialize(Model.Numbers)))

Optional

A tip for passing strings. You may want JSON encoder to not escape some symbols in your strings. In this example I want raw unescaped cyrillic letters. In your view:

strings = @(
new HtmlString(
    JsonSerializer.Serialize(Model.Strings, new JsonSerializerOptions
    {
        Encoder = JavaScriptEncoder.Create(
            UnicodeRanges.BasicLatin,
            UnicodeRanges.Cyrillic)
    })))
user_3802470
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