C＃中KeyUp事件處理程序的速率限制

Question

我想驗證文本字段上的輸入作爲用戶類型。這個功能可以正常工作，但是我想限制驗證，因爲它正在打外部API。我想只在用戶輸入750毫秒後執行驗證。我只是用這個

ATM：

private void Configure_Load(object sender, EventArgs e) 
{ 
    endpointBox.KeyUp += EndpointBox_KeyUp; 
} 

void EndpointBox_KeyUp(object sender, KeyEventArgs e) 
{ 
    TestHTTP200(endpointBox.Text); 
} 

Answer 1

使用Timer控制

System.Windows.Forms.Timer myTimer = new System.Windows.Forms.Timer(); 
private void Configure_Load(object sender, EventArgs e) 
{ 
    endpointBox.KeyUp += EndpointBox_KeyUp; 
    myTimer.Tick +=new EventHandler(OnTimedEvent);  //EDIT: should not be `ElapsedEventHandler` 
    myTimer.Interval=750; 
} 

void EndpointBox_KeyUp(object sender, KeyEventArgs e) 
{  
    myTimer.Stop(); 
    myTimer.Start(); 
} 


private void OnTimedEvent(Object myObject,EventArgs myEventArgs) 
{ 
     myTimer.Stop(); 
     TestHTTP200(endpointBox.Text); 
} 

Answer 2

您想等於JavaScript的setTimeout的方法等。當用戶提供更多輸入時，這可以被取消：

代碼取自here。

public static IDisposable SetTimeout(Action method, int delayInMilliseconds) 
    { 
     System.Timers.Timer timer = new System.Timers.Timer(delayInMilliseconds); 
     timer.Elapsed += (source, e) => 
     { 
      method(); 
     }; 

     timer.AutoReset = false; 
     timer.Enabled = true; 
     timer.Start(); 

     // Returns a stop handle which can be used for stopping 
     // the timer, if required 
     return timer as IDisposable; 
    } 

然後你可以在你的鑰匙了處理程序使用此：

void EndpointBox_KeyUp(object sender, KeyEventArgs e) 
    { 
     IDisposable timeout = SetTimeout(() => TestHTTP200(endpointBox.Text), 750); 
     if (this.currentTimeout != null) { 
      this.currentTimeout.Dispose(); 
      this.currentTimeout = timeout; 
     } 
    } 

這是最基本的原則，至少，每次重新開始一個750毫秒超時的用戶類型做你的事，並取消任何待定的計時器。

更新：完整的代碼示例：

public partial class Form1 : Form 
{ 
    private IDisposable currentTimeout; 

    public Form1() 
    { 
     InitializeComponent(); 
    } 

    private void EndpointBox_KeyUp(object sender, KeyEventArgs e) 
    { 
     IDisposable timeout = TimerHelper.SetTimeout(() => TestHTTP200(EndpointBox.Text), 750); 
     if (this.currentTimeout != null) 
     { 
      this.currentTimeout.Dispose(); 
      this.currentTimeout = timeout; 
     } 
    } 

    private void TestHTTP200(string text) 
    { 
     //... 
    } 
} 

public class TimerHelper 
{ 
    public static IDisposable SetTimeout(Action method, int delayInMilliseconds) 
    { 
     System.Timers.Timer timer = new System.Timers.Timer(delayInMilliseconds); 
     timer.Elapsed += (source, e) => 
     { 
      method(); 
     }; 

     timer.AutoReset = false; 
     timer.Enabled = true; 
     timer.Start(); 

     // Returns a stop handle which can be used for stopping 
     // the timer, if required 
     return timer as IDisposable; 
    } 
}