Event handlers

Matt brown

12y1.4kC#

How can you have a single event handler for Multiple Buttons?
Is there a way to simplify the code?

Like for example if you have button 1 that nagivate to another page. Then you have another Button that fires an event.

How can you create a single Event handler for both or more in C sharp VS 2013?

Thank you!!!!

7 Replies

Know the answer? Post it — somebody with the same question will find it here.

Vulpes12y ago
Accepted answer
Well, if you've wired up the Click event for all 6 buttons to a single handler - as previously described - then you can put this line in the handler to determine which button was pressed:

int btnNum = ((Button)sender).Name[6] - 48;

This works by taking the 7th (and last character of the name) which will be '1' to '6'. These characters have an ASCII value of 49 to 54 so if we deduct 48, we will get the actual integer value of the character.

You can then use that integer (minus 1) as an index into your 'urls' array and navigate to it.
Vulpes12y ago
Yes, it should work for images as well.
Matt brown12y ago
Thank you! Can this method work with images as well? If you have multiple images and they nagivate to a rootpage.
Matt brown12y ago
Can you please explain how I can use one line code for all 6 button? I am new at this. Thank you and sorry for the trouble.
Vulpes12y ago
Well you can certainly use the same event handler for all 6 buttons if it's working for 2 in your Windows Store app.

If the buttons are numbered consecutively - button1 to button6 - then you could determine which one was pressed with one line of code :

int btnNum = ((Button)sender).Name[6] - 48;

If you then have a string array with 6 urls, you could navigate to the appropriate one which would be urls[btnNum - 1].
Matt brown12y ago
This method does work. I have seen it. But it there a way to simplify the code more?

Like I have 6 buttons. They all navigate to some pages. Is there any way to wrap them in a few line of code? Basically all they are use for is nagivation.

Thank you
Vulpes12y ago
I don't know about Window Store apps but in a WPF app, if you've already added a Click handler for one button then, in the Properties Box for a second button when you navigate to its Click event, you'll find that there's a drop down which enables you to select the same handler as you've already added for the first button.

You can also do this dynamically in code like this:

button1.Click += button_Click;
button2.Click += button_Click; // same handler

and ascertain which button was actually pressed using the 'sender' parameter:

private void button_Click(object sender, RoutedEventArgs e)
{
Button b = (Button)sender;
if (b.Name == "button1")
{
// do something
}
else if (b.Name == button2)
{
// do something else
}
}