ant-design-blazor/components/icon/IconService.cs

using System;
using System.Collections.Concurrent;
using System.Collections.Generic;
using System.Net.Http;
using System.Threading.Tasks;
using Microsoft.AspNetCore.Components;
using Microsoft.JSInterop;

namespace AntDesign
{
    public class IconService
    {
        private static readonly ConcurrentDictionary<string, string> _svgCache = new ConcurrentDictionary<string, string>();
        private static readonly ConcurrentDictionary<string, string> _customCache = new ConcurrentDictionary<string, string>();
        private readonly HttpClient _httpClient;
        private IJSRuntime _js;

        public IconService(HttpClient httpClient, NavigationManager navigationManager, IJSRuntime js)
        {
            if (httpClient != null && navigationManager != null)
                httpClient.BaseAddress = new Uri(navigationManager.BaseUri);

            _httpClient = httpClient;
            _js = js;
        }

        public async ValueTask<string> GetIconImg(string type, string theme)
        {
            var iconImg = string.Empty;
            if (_svgCache.TryGetValue($"{theme}-{type}", out var img))
            {
                iconImg = img;
            }
            else
            {
                var res = await _httpClient.GetAsync($"_content/AntDesign/icons/{theme}/{type}.svg");
                if (res.IsSuccessStatusCode)
                {
                    iconImg = await res.Content.ReadAsStringAsync();
                    _svgCache.TryAdd($"{theme}-{type}", iconImg);
                }
            }
            return iconImg;
        }

        public static string GetStyledSvg(string svgImg, string width = "1em", string height = "1em", string fill = "currentColor", int rotate = 0, bool spin = false)
        {
            var svgStyle = $"focusable=\"false\" width=\"{width}\" height=\"{height}\" fill=\"{fill}\" style=\"transform: rotate({rotate}deg); \" {(spin ? "class=\"anticon-spin\"" : "")}";
            if (!string.IsNullOrEmpty(svgImg))
            {
                return svgImg.Insert(svgImg.IndexOf("svg", StringComparison.Ordinal) + 3, $" {svgStyle} ");
            }

            return null;
        }

        public async ValueTask CreateFromIconfontCN(string scriptUrl)
        {
            if (string.IsNullOrEmpty(scriptUrl))
            {
                return;
            }

            //if (_customCache.ContainsKey(scriptUrl))
            //{
            //    return;
            //}

            await _js.InvokeVoidAsync(JSInteropConstants.CreateIconFromfontCN, scriptUrl);
            //_customCache[scriptUrl] = scriptUrl;
        }
    }
}