Sender Eventargs E Private Void

Sender Eventargs E Private Void

What are the parameters (Object sender, EventArgs e) in the events? – C#
I was reviewing the topic of events in C#, I looked for some examples and I usually see examples where the following fields appear (object sender , EventArgs e), this is a code that I understand related to the topic of events and does not have the fields (object sender ,eventargs e) I also clarify that I understand the issue of delegates and all this code fragment, my problem is with the other format.
but I can't understand very well the other event syntax format, that is, according to lei sender it refers to the class that triggered the event and eventargs to the fields, but I can't understand it well… for example: if I had more than a parameter, would I have to put something like (object sender,eventsargs A , eventargs B)?
It would help me if you could explain to me in some simple code what these 2 fields are and why sender is so necessary.
In event handlers there are usually two input parameters: object sender and EventArgs e .
Let's take a look at the handler for a ButtonClick event:
Here, sender refers to the object that fired the event. That is, in this case it will contain the instance of the button that fired the Click event.
As for EventArgs , this is a generic class for passing event information. In the case of a button's Click event, it doesn't really contain anything since only the generic class is passed. But let's look at another event, for example MouseClick :
As you can see, in this case the EventArgs generic class is not passed, but MouseEventArgs . The signature of this class is as follows:
That is, it inherits from EventArgs and contains several properties that give information about the event: Button , Clicks , Delta , Location , X and Y .
If I had more than one parameter, would I have to put something like (object sender,eventsargs A , eventargs B)?
No. What you need to do is create a class that inherits from EventArgs , with the properties you need to create to pass the information that interests you, and the signature of your EventHandler would be something like
and you would access the properties with e . MiPropiedad1 , e . MiPropiedad2 , etc.
I hope I have been able to explain myself well, if you have any questions or do not understand something, do not hesitate to comment and I will try to improve my answer.

Table of contents

Exit focus mode

Light

Dark

High contrast

Light

Dark

High contrast

This browser is no longer supported.
Upgrade to Microsoft Edge to take advantage of the latest features, security updates, and technical support.
An event handler is a method that is bound to an event. When the event is raised, the code within the event handler is executed. Each event handler provides two parameters that allow you to handle the event properly. The following example shows an event handler for a Button control's Click event.
The first parameter, sender , provides a reference to the object that raised the event. The second parameter, e , in the example above, passes an object specific to the event that is being handled. By referencing the object's properties (and, sometimes, its methods), you can obtain information such as the location of the mouse for mouse events or data being transferred in drag-and-drop events.
Typically each event produces an event handler with a different event-object type for the second parameter. Some event handlers, such as those for the MouseDown and MouseUp events, have the same object type for their second parameter. For these types of events, you can use the same event handler to handle both events.
You can also use the same event handler to handle the same event for different controls. For example, if you have a group of RadioButton controls on a form, you could create a single event handler for the Click event and have each control's Click event bound to the single event handler. For more information, see How to: Connect Multiple Events to a Single Event Handler in Windows Forms .

Maximize your points with the Microsoft Rewards extension
Quick access to your daily points and offers

More

Home

UWP apps

Get started

Design

Develop

Publish

Resources

API reference

Downloads

Samples

Support

All Microsoft

Microsoft Security

Azure

Dynamics 365

Microsoft 365

Microsoft Teams

Windows 365

Tech & innovation
Tech & innovation

Microsoft Cloud

AI

Azure Space

Mixed reality

Microsoft HoloLens

Microsoft Viva

Quantum computing

Sustainability

Industries
Industries

Education

Automotive

Financial services

Government

Healthcare

Manufacturing

Retail

All industries

Partners
Partners

Find a partner

Become a partner

Partner Network

Find an advertising partner

Become an advertising partner

Azure Marketplace

AppSource

Resources
Resources

Blog

Microsoft Advertising

Developer Center

Documentation

Events

Licensing

Microsoft Learn

Microsoft Research

View Sitemap

View account Review and manage your work or school account information

Moved by
CoolDadTx
Sunday, December 23, 2012 10:12 PM
Winforms related (From:Visual C# )

If you are removing the selected item, does your code within the SelectedIndexChanged event handler assume that an item is selected? If so, you would get an error, because upon removing the selected item, none is selected.
hmm it doesn't seem to work it is still doing the same thing.
Can you give us the exact error message, and the code for your " listBox1_SelectedIndexChanged " method, including which line the error occurs?
The error does not occur on that line.

If you mean the first line in that routine, please show that line. We cannot help you without knowing what you are doing wrong...
This forum has migrated to Microsoft Q&A . Visit Microsoft Q&A to post new questions.
When I try to remove an item from a listbox i get an error at
Usually to remove its better not to remove it directly from the listBox items collections, but to put all selected items into an additional list and then by looping through this list remove items.
...if true, set new selection (1up/1dn/0) without selecting (it will prevent triggering SelectedIndexChanged):
Classified SR-2 | 2x Xeon W5580 - 3.20 GHz | 12x 2GB Kingston KHX2000C9D3T1K3/6GX | 2x MARS II/2DIS/3GD5 | SAMSUNG 830 MZ-7PC512D/AM 2.5" 512GB SATA III MLC | 4x Spinpoint F3EG HD503HI 500GB 5400 16MB SATA 3.0Gb/s |

Wednesday, September 07, 2022 08:00
using System;

namespace HelloWorld
{
public class TrainSignal
{
public event Action TrainsArecoming;

public void TriggerTrainSignal()
{
// call all subscribers
if (TrainsArecoming != null) // make sure there are subscribers!
TrainsArecoming(); // trigger the event
}
}

public class Program
{
static void Main()
{

Console.Read();
}
}
}
        public event Action TrainsArecoming ;
        public void TriggerTrainSignal ( )
            // call all subscribers
            if ( TrainsArecoming != null ) // make sure there are subscribers!
                TrainsArecoming ( ) ; // trigger the event
using System;

namespace HelloWorld
{
public class TrainSignal
{
public event EventHandler TrainsArecoming;

public void TriggerTrainSignal()
{
// call all subscribers
if (TrainsArecoming != null) // make sure there are subscribers!
TrainsArecoming(); // trigger the event
}
}

public class Program
{
static void Main()
{

Console.Read();
}
}
}
        public event EventHandler TrainsArecoming ;
        public void TriggerTrainSignal ( )
            // call all subscribers
            if ( TrainsArecoming != null ) // make sure there are subscribers!
                TrainsArecoming ( ) ; // trigger the event
using System;

namespace HelloWorld
{
public enum TrainSignalType
{
AudioSignal,
VisualSignal
}

public class TrainSignal
{
public event EventHandler TrainsArecoming;

public TrainSignalType SignalType { get; set; }

public void TriggerTrainSignal()
{
// call all subscribers
if (TrainsArecoming != null) // make sure there are subscribers!
TrainsArecoming(this, EventArgs.Empty); // trigger the event
}
}

public class Program
{
static void Main()
{

Console.Read();
}
}
}
        public event EventHandler TrainsArecoming ;
        public TrainSignalType SignalType { get ; set ; }
        public void TriggerTrainSignal ( )
            // call all subscribers
            if ( TrainsArecoming != null ) // make sure there are subscribers!
                TrainsArecoming ( this , EventArgs . Empty ) ; // trigger the event
using System;

namespace HelloWorld
{
public enum TrainSignalType
{
AudioSignal,
VisualSignal
}

public class TrainSignal
{
public event EventHandler TrainsArecoming;

public TrainSignalType SignalType { get; set; }

public void TriggerTrainSignal()
{
// call all subscribers
if (TrainsArecoming != null) // make sure there are subscribers!
TrainsArecoming(this, EventArgs.Empty); // trigger the event
}
}

public class Program
{
static void Main()
{
TrainSignal trainSignalAudio = new TrainSignal() { SignalType = TrainSignalType.AudioSignal };
TrainSignal trainSignalVisual = new TrainSignal() { SignalType = TrainSignalType.VisualSignal };

Console.Read();
}
}
}
        public event EventHandler TrainsArecoming ;
        public TrainSignalType SignalType { get ; set ; }
        public void TriggerTrainSignal ( )
            // call all subscribers
            if ( TrainsArecoming != null ) // make sure there are subscribers!
                TrainsArecoming ( this , EventArgs . Empty ) ; // trigger the event
            TrainSignal trainSignalAudio = new TrainSignal ( ) { SignalType = TrainSignalType . AudioSignal } ;
            TrainSignal trainSignalVisual = new TrainSignal ( ) { SignalType = TrainSignalType . VisualSignal } ;
using System;

namespace HelloWorld
{
public enum TrainSignalType
{
AudioSignal,
VisualSignal
}

public class TrainSignal
{
public event EventHandler TrainsArecoming;

public TrainSignalType SignalType { get; set; }

public void TriggerTrainSignal()
{
// call all subscribers
if (TrainsArecoming != null) // make sure there are subscribers!
TrainsArecoming(this, EventArgs.Empty); // trigger the event
}
}

public class Program
{
static void Main()
{
TrainSignal trainSignalAudio = new TrainSignal() { SignalType = TrainSignalType.AudioSignal };
TrainSignal trainSignalVisual = new TrainSignal() { SignalType = TrainSignalType.VisualSignal };

Console.Read();
}

private static void StopTheCar(object sender, EventArgs e)
{

}
}
}
        public event EventHandler TrainsArecoming ;
        public TrainSignalType SignalType { get ; set ; }
        public void TriggerTrainSignal ( )
            // call all subscribers
            if ( TrainsArecoming != null ) // make sure there are subscribers!
                TrainsArecoming ( this , EventArgs . Empty ) ; // trigger the event
            TrainSignal trainSignalAudio = new TrainSignal ( ) { SignalType = TrainSignalType . AudioSignal } ;
            TrainSignal trainSignalVisual = new TrainSignal ( ) { SignalType = TrainSignalType . VisualSignal } ;
        private static void StopTheCar ( object sender , EventArgs e )
using System;

namespace HelloWorld
{
public enum TrainSignalType
{
AudioSignal,
VisualSignal
}

public class TrainSignal
{
public event EventHandler TrainsArecoming;

public TrainSignalType SignalType { get; set; }

public void TriggerTrainSignal()
{
// call all subscribers
if (TrainsArecoming != null) // make sure there are subscribers!
TrainsArecoming(this, EventArgs.Empty); // trigger the event
}
}

public class Program
{
static void Main()
{
TrainSignal trainSignalAudio = new TrainSignal() { SignalType = TrainSignalType.AudioSignal };
TrainSignal trainSignalVisual = new TrainSignal() { SignalType = TrainSignalType.VisualSignal };

Console.Read();
}

private static void StopTheCar(object sender, EventArgs e)
{
TrainSignal trainSignal = sender as TrainSignal; // similar to TrainSignal trainSignal = (TrainSignal)sender;
}
}
}
        public event EventHandler TrainsArecoming ;
        public TrainSignalType SignalType { get ; set ; }
        public void TriggerTrainSignal ( )
            // call all subscribers
            if ( TrainsArecoming != null ) // make sure there are subscribers!
                TrainsArecoming ( this , EventArgs . Empty ) ; // trigger the event
            TrainSignal trainSignalAudio = new TrainSignal ( ) { SignalType = TrainSignalType . AudioSignal } ;
            TrainSignal trainSignalVisual = new TrainSignal ( ) { SignalType = TrainSignalType . VisualSignal } ;
        private static void StopTheCar ( object sender , EventArgs e )
            TrainSignal trainSignal = sender as TrainSignal ; // similar to TrainSignal trainSignal = (TrainSignal)sender;
using System;

namespace HelloWorld
{
public enum TrainSignalType
{
AudioSignal,
VisualSignal
}

public class TrainSignal
{
public event EventHandler TrainsArecoming;

public TrainSignalType SignalType { get; set; }

public void TriggerTrainSignal()
{
// call all subscribers
if (TrainsArecoming != null) // make sure there are subscribers!
TrainsArecoming(this, EventArgs.Empty); // trigger the event
}
}

public class Program
{
static void Main()
{
TrainSignal trainSignalAudio = new TrainSignal() { SignalType = TrainSignalType.AudioSignal };
trainSignalAudio.TrainsArecoming += StopTheCar;

TrainSignal trainSignalVisual = new TrainSignal() { SignalType = TrainSignalType.VisualSignal };
trainSignalVisual.TrainsArecoming += StopTheCar;

trainSignalAudi
Buck Gardner Double Nasty Ii
Nasty Family Tube
Bbw Mature Fucking

Sender Eventargs E Private Void

Report Page