Include "for" loop in button name

Question

How can I include the "for" loop in the name of the button?

        for (int i = 1; i <= 10; i++)
        {
            button[i].Text = "0";
        }

Is there any way to make this work? Thank you!

What's the result that you want to achieve? A button with a label that reads `0000000000`? — Sergey Kalinichenko, Dec 25 '13 at 13:21
... and of [this](http://stackoverflow.com/questions/12055648/converting-string-to-a-control-name-in-c-sharp) and [this](http://stackoverflow.com/questions/18248989/how-to-concat-variable-integer-in-control-name-in-vb-net) and [this](http://stackoverflow.com/questions/3459230/dynamic-variable-name-use-in-c-sharp-for-winforms) and [this](http://stackoverflow.com/questions/14578957/equivalent-to-refer-to-control-by-variable-name) ... — O. R. Mapper, Dec 25 '13 at 13:35

score 4 · Answer 1 · edited Dec 25 '13 at 13:29

4

Yes, you can access a button with it's name like this:

    for (int i = 1; i <= 10; i++)
    {
        string buttonName = "button" + i;
        this.Controls[buttonName].Text = "0";
    }

edited Dec 25 '13 at 13:29

Rohit Vats

answered Dec 25 '13 at 13:21

Selman Genç

I get "Object reference not set to an instance of an object." on the second line of code. – user2992015 Dec 25 '13 at 13:31
@user2992015: On `{`? – O. R. Mapper Dec 25 '13 at 13:32
on "this.Controls[buttonName].Text = "0";" – user2992015 Dec 25 '13 at 13:33
Check your button names and change buttonName's value. What is your button names ? If your button names like "button1","button2" .. this code should work..you are getting that error because your button names are different – Selman Genç Dec 25 '13 at 13:34
My buttons names are "button1" to "button10". – user2992015 Dec 25 '13 at 13:39
Where is your buttons, inside of your Form or Panel ?? – Selman Genç Dec 25 '13 at 13:40
Button are inside my form. I tried to write this code: "this.Controls[button1].Text = "0";" and got "Error: The best overloaded method match for 'System.Windows.Forms.Control.ControlCollection.this[int]' has some invalid arguments" – user2992015 Dec 25 '13 at 13:42

score 1 · Answer 2 · answered Dec 25 '13 at 13:21

1

Initialize an array of Button:

Button btnsarr = new Button[ DefineTheSize ]();

and add all buttons in it:

btnarr[0] = button1;
btnarr[1] = button2;
btnarr[2] = button3;
// and so on

now you can use this array in the you want.

for (int i = 1; i <= btnarr.Length; i++)
{
    btnsarr[i].Text = "0";
}

answered Dec 25 '13 at 13:21

Shaharyar

You are adding same button multiple times in an array. – Rohit Vats Dec 25 '13 at 13:25
@RohitVats That was just a sample. Anyway ! I've corrected it. – Shaharyar Dec 25 '13 at 13:25
Moreover, i think there is no need of creating an array at all. Buttons can be accessed from `Controls collection` like [Selman22](http://stackoverflow.com/a/20773234/632337) mentioned in his answer already. – Rohit Vats Dec 25 '13 at 13:27
@RohitVats: Unless there are *only* those buttons around, the complete collection of contorls would have to be filtered, which is not a clean solution compared to an array that contains exactly the buttons that should be processed. – O. R. Mapper Dec 25 '13 at 13:38
@O.R.Mapper - Sorry mate didn't get you. All collection will be filtered. What? – Rohit Vats Dec 25 '13 at 13:46
1

@RohitVats: If you put the buttons that should be included in the loop into an array once upon initialization, you can simply loop over the array. If you loop directly over the controls collection, you will have to spend some additional effort on checking which controls you actually want every time you loop over the collection. – O. R. Mapper Dec 25 '13 at 13:47

score 0 · Answer 3 · answered Dec 25 '13 at 13:38

0

Best way to do this is:

foreach (Button button in this.Controls.OfType<Button>().ToArray())
     button.Text = "0";

answered Dec 25 '13 at 13:38

Ankush Madankar

This will break as soon as there is any button on the form that is not supposed to be subject to the text assignment. – O. R. Mapper Dec 25 '13 at 13:45
@O. R. Mapper I dont think so there is any such button which not support text assignment – Ankush Madankar Dec 25 '13 at 13:59
The OP doesn't state whether or not there is any such button. Even if there isn't any right now, I'd be careful about calling something that breaks on the first tiny change to the surrounding UI as the "best way". – O. R. Mapper Dec 25 '13 at 14:04
@O. R. Magger So how should I check this? C# provide to check so? – Ankush Madankar Dec 25 '13 at 14:32
Instead of using `this.Controls`, you can add the buttons you want to treat with the loop into a list or an array, as shown in [Shaharyar's](http://stackoverflow.com/users/1910920/shaharyar) answer, and then iterate over that. – O. R. Mapper Dec 25 '13 at 14:59

3 Answers3