refactor: 更改返回值为可为空对象

Author: ArgoZhang

src/BootstrapBlazor/Services/DefaultNetworkMonitorService.cs

@@ -34,10 +34,10 @@ public DefaultNetowrkMonitorService(IJSRuntime jsRuntime)
     /// <summary>
     /// <inheritdoc/>
     /// </summary>
-    public async Task<NetworkMonitorState> GetNetworkMonitorState(CancellationToken token = default)
+    public async Task<NetworkMonitorState?> GetNetworkMonitorState(CancellationToken token = default)
     {
         _module ??= await LoadModule();
-        return await _module.InvokeAsync<NetworkMonitorState?>("getNetworkInfo", token) ?? new();
+        return await _module.InvokeAsync<NetworkMonitorState?>("getNetworkInfo", token);
     }
 
     /// <summary>

src/BootstrapBlazor/Services/INetworkMonitorService.cs

@@ -16,7 +16,7 @@ public interface INetworkMonitorService
     /// <param name="token">A cancellation token that can be used to cancel the operation.</param>
     /// <returns>A task representing the asynchronous operation. The task result contains the current <see
     /// cref="NetworkMonitorState"/>.</returns>
-    Task<NetworkMonitorState> GetNetworkMonitorState(CancellationToken token = default);
+    Task<NetworkMonitorState?> GetNetworkMonitorState(CancellationToken token = default);
 
     /// <summary>
     /// Registers a callback to be invoked when the network monitor state changes.