使用计时器每 5 分钟运行一次 Asp.net 代码

Question

I get the following error on page_load:

c# no argument given that corresponds to the required formal parameter

Why is this?

protected void Page_Load(object sender, EventArgs e)
{
    timerevent();
}

DataSet _dataSet = new DataSet();
private DataTable _dataTable; 

string _sqlQuery = @"show slave status;";
string _sqlStop = @"stop slave;";
string _sqlStart = @"start slave;";
System.Timers.Timer mytimer = new System.Timers.Timer();


private void SetTimer()
{
    mytimer.Elapsed += new ElapsedEventHandler(timerevent);
    mytimer.Interval = 1000;
}

private void timerevent(object sender, ElapsedEventArgs e)
{
    BindData();
}

public void BindData()
{
    mytimer.Start();
}

Answer 1

Did you stop to consider the lifecycle of a Page? Think about it.

An instance of your Page class is created when an HTTP request comes in. Once the page has gone through all of its lifecycle events, an HTTP response is sent to the client. At that point, the Page instance will be destroyed. It will go away, taking any state stored in it (such as field containing a timer) with it.

For these reasons, the approach you're trying simply will not work.

If you want to update the client's DOM update every 5 minutes, you'll either have to have some client side code (JavaScript) that contains a timer and initiates a new HTTP request, or use tech like web sockets ( SignalR ) to push changes. If you do choose a SignalR approach, you can have a separate service with scheduling functionality (perhaps using Hangfire or Quartz ) to initiate the push.