How can I subscribe multiple buttons to the same event handler and act according to what button was clicked?

Question

I have 6 buttons that I want to be attached to the same handler. How can I do this?

Psychodrama

That's what I'm trying to avoid. I can double click the buttons on the designer view and generate 6 stubs, but why would I want to do that when I can just subscribe the buttons to a single event. – Psychodrama

rather than double-click, drop the list down and select the existing handler... – Vallombrosa

Answer 1

When you subscribe to the event on a button, it's just a standard event handler:

button1.Click += myEventHandler;

You can use the same code to add handlers for every button:

button1.Click += myEventHandler;
button2.Click += myEventHandler;
button3.Click += myEventHandler;
button4.Click += myEventHandler;
button5.Click += myEventHandler;
button6.Click += myEventHandler;

This will cause your handler in myEventHandler to be run when any of the buttons are clicked.

Deannadeanne

Answer 2

You can attach the same event to multiple buttons by binding the same method to each buttons click event

myButton1.Click += new MyButtonClick;
myButton2.Click += new MyButtonClick;
myButton3.Click += new MyButtonClick;
myButton4.Click += new MyButtonClick;
myButton5.Click += new MyButtonClick;
myButton6.Click += new MyButtonClick;

void MyButtonClick(object sender, EventArgs e)
{
    Button button = sender as Button;
    //here you can check which button was clicked by the sender
}

Diplosis

I have used CommandName and CommandArgument to identify the different buttons linked to same onclick event. I gave +1 for u. – Hus

I had to remove the new keyword to make this work. – Bechuanaland

Answer 3

Just wire the buttons to the same event:

myButton1.Click += Button_Click;
myButton2.Click += Button_Click;
myButton3.Click += Button_Click;
...

And handle the buttons accordingly:

private void Button_Click(object sender, EventArgs e)
{
    string buttonText = ((Button)sender).Text;

    switch (buttonText)
    {
        ...
    }
}

The sender object contains the reference to the button which caused the Click event. You can cast it back to Button, and access whatever property you need to distinguish the actual button.

Spinelli

The cast ended up with missing assembly information. – Hillel

Answer 4

How to see which button was pressed:

Use the sender

Button myButton = (Button)sender;

sender is a parameter of type object in your event handler.

Haw

Answer 5

Instead of double clicking the event in the designer you can paste the name of the event handler to to the event in the designer property grid.

Frowst

Answer 6

myButton1.Click += new EventHandler(MyButtonClick);
myButton2.Click += new EventHandler(MyButtonClick);
myButton3.Click += new EventHandler(MyButtonClick);
myButton4.Click += new EventHandler(MyButtonClick);
myButton5.Click += new EventHandler(MyButtonClick);
myButton6.Click += new EventHandler(MyButtonClick);

public void MyButtonClick(object sender, MouseButtonEventArgs e)
{
                switch ((sender as Button).Name)
                {
                case "button1":
                    //actions
                    break;
                case "button2":
                    //actions
                    break;
                default:
                    break;
               }
}

Maffei

It says "The type or name space for button could not be found." – Hillel

Answer 7

I'm not an expert but I use this and it looks pretty simple

<Button x:Name="Button1" Content="Button" Click="Button_Click"/>
<Button x:Name="Button2" Content="Button" Click="Button_Click"/>

Just give both buttons the same click event

Elephant

Answer 8

 button1.Click += button_Click;
 button2.Click += button_Click;

void button_Click(object sender, EventArgs e)
        {
            if (sender == button1)
            {
                this.Text = "1";
            }
            else if (sender == button2)
            {
                this.Text = "2";
            }
        }

Burchell

Can you explain your answer a bit? – Intermixture

Answer 9

In main.axml add this to all the buttons

android:clickable="whateveryoulike"

and all the buttons need to have the same id

in the MainActivity

[Java.Interop.Export("whateveryoulike")]
void whateveryoulike2(View v){
Button button=(Button) v;
//your code here
}

the name of the method doesnt matter

Adrienadriena