下面是一个在Blazor应用中实现数据恢复的示例代码:
// 定义一个服务来管理数据恢复
public class DataRecoveryService
{
private Dictionary
public void Add(string key, object value)
{
_data[key] = value;
}
public T Get(string key)
{
if(_data.TryGetValue(key, out object value))
{
return (T)value;
}
return default;
}
public void Remove(string key)
{
_data.Remove(key);
}
}
// 注册服务
builder.Services.AddSingleton
// 注册SignalR客户端功能 builder.Services.AddSignalR(e => { // 设置断线重连策略为立即重连 e.ClientOptions.Transports = HttpTransportType.WebSockets; e.ClientOptions.DisconnectedThreshold = TimeSpan.FromSeconds(0); });
// 注册SignalR中间件
app.UseEndpoints(endpoints =>
{
endpoints.MapControllers();
endpoints.MapHub
@page "/" @inject DataRecoveryService dataService
// Blazor组件中使用数据 @code { private string _username; private string _message;
protected override async Task OnInitializedAsync()
{
// 从数据恢复服务中检索数据
_username = dataService.Get("Username");
_message = dataService.Get("Message");
// 订阅SignalR的Disconnected事件
_hubConnection.Closed += async (error) =>
{
// 保存数据以便重新连接
dataService.Add("Username", _username);
dataService.Add("Message", _message);
// 等待重新连接
await Task.Delay(new Random().Next(0, 5) * 1000);
// 重新连接
await TryConnect();
};
}
private async Task TryConnect()
{
try
{
await _hubConnection.StartAsync();
}
catch (Exception ex)
{
Console.Error.WriteLine(ex.Message);
}
}
}