'method'没有重载匹配委托'System.EventHandler'

I am trying to build a program that, once the button was click, every 5 second will perform the function (OnTimed).

我正在尝试构建一个程序,一旦按下按钮,每5秒钟将执行该功能(OnTimed)。

Below is the code so far:

以下是目前的代码:

private void bntCapture_Click(object sender, RoutedEventArgs e)
{ 
    DispatcherTimer t1 = new DispatcherTimer();
    t1.Interval = TimeSpan.FromMilliseconds(5000);
    t1.IsEnabled = true;
    t1.Tick += new EventHandler(OnTimed);
    t1.Start();
}

void OnTimed(object sender, ElapsedEventArgs e)
{

    imgCapture.Source = imgVideo.Source;
    System.Threading.Thread.Sleep(1000);
    Helper.SaveImageCapture((BitmapSource)imgCapture.Source);
}

When i run the code, it show the error:

当我运行代码时,它显示错误:

"No overload for 'method' matches delegate 'System.EventHandler'

“'方法'没有重载匹配委托'System.EventHandler'

6 个解决方案

#1

The signature of the event-handler method isn't compatible with the delegate type.

事件处理程序方法的签名与委托类型不兼容。

Subsribers to the DispatcherTimer.Tick event must be of the EventHandler delegate type, which is declared as:

DispatcherTimer.Tick事件的订阅者必须是EventHandler委托类型,声明为:

public delegate void EventHandler(object sender, EventArgs e);

Try this instead:

试试这个:

void OnTimed(object sender, EventArgs e)
{
   ...
}

#2

If you using Windows phone 8.1 then you need the following

如果您使用Windows Phone 8.1,则需要以下内容

private void OnTimed(object sender, object e) {
      // You Code Here
 }

#3

Method OnTimed has to declared like this:

方法OnTimed必须像这样声明:

 private void OnTimed(object sender, EventArgs e)
 {
     // Do something
 }

#4

Dispatcher.Tick is simple EventHandler:

Dispatcher.Tick是简单的EventHandler:

public event EventHandler Tick;

公共事件EventHandler Tick;

So EventHandler parameters should be:

所以EventHandler参数应该是:

void OnTimed(object sender, EventArgs e)

Not the

void OnTimed(object sender, ElapsedEventArgs e)

Looks like you a bit overlooked around the System.Timers.Timer.Elapsed event which is:

看起来你有点忽略了System.Timers.Timer.Elapsed事件,它是:

public event ElapsedEventHandler Elapsed

public delegate void ElapsedEventHandler(
    Object sender,
    ElapsedEventArgs e
)

#5

I know it might be a little bit late, but i just wanted to throw in a bit more for anyone with this problem:

我知道这可能有点晚了,但我只是想为这个问题的任何人多投入一点:

timer.Tick += new EventHandler(Method);

public void Method(object sender, EventArgs e)
{
//Do Something
}

solves the Problem.

解决问题。

It can also be written like this: timer.Tick += Method;

它也可以这样写:timer.Tick + = Method;

timer.Tick += Method;

public void Method(object sender, EventArgs e)
{
//Do Something
}

Hope it helps!

希望能帮助到你!

#6

-1

In my case I was using a custom winforms control for digitalPersona fingerprint recognition.

在我的情况下,我使用自定义winforms控件进行digitalPersona指纹识别。

When I tried to overload the 'OnComplete' method it would come up with 'No overload...'

当我试图重载“OnComplete”方法时,它会提出“没有超载......”

private void FingerprintVerificationControl_OnComplete(object control, DPFP.FeatureSet featureSet, DPFP.Gui.EventHandlerStatus eventHandlerStatus)

This is what it looked like.

这就是它的样子。

I looked into the assembly and I noticed that third parameter had the 'ref' keyword attached to it. I added it in my code and it worked:

我查看了程序集,我注意到第三个参数附加了'ref'关键字。我在我的代码中添加了它并且它有效:

private void FingerprintVerificationControl_OnComplete(object control, DPFP.FeatureSet featureSet, ref DPFP.Gui.EventHandlerStatus eventHandlerStatus)

#1