How to get a button by variable name using a string?

Question

My code is like this...

public class MainActivity extends Activity {
    String a = new String("1,2,3,4,5")

    private Button button1;
    private Button button2;
    private Button button3;
    private Button button4;
    private Button button5;

    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        startBtn = (Button) findViewById(R.id.startBtn);

        startBtn.setOnClickListener(new OnClickListener() {

            @Override
            public void onClick(View view) {
                String[] splited=a.split(",");
                for(String b : splited){
                    (button"b").setBackground(Color.RED); 
                   //This is the part where I get stucked//
                    //I know the code is wrong but I just want to express my idea//
                }
            }
        });
    }
}

So,how can I name the button with a changing String b?

The button1 should changing its background color first, then button2, button3, and so on.

Any ideas?

Patrick Kostjens · Accepted Answer · 2014-09-07 08:33:32Z

5

No, That is not the way. You cannot do that for a variable name (unless you use reflection). Instead of that string take a Button array.

private Button[] buttons = {button1,button2.....};

Later

for(Button b : buttons ){
    b.setBackground(Color.RED);     
}

edited Sep 7, 2014 at 8:33

Patrick Kostjens

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answered Aug 21, 2014 at 7:43

Suresh Atta

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2 Comments

user3947486 Over a year ago

oh yes a button array!However, if I want to set the order of the button according to the string values(which the string values will change), is there a way to do this?

Suresh Atta Over a year ago

@user3947486 Yes. An arraylist is waiting for you :)

0101100101 · Accepted Answer · 2014-08-21 09:33:51Z

1

There's only two ways:

What Suresh Atta mentioned, because it's not possible to access variable names without reflection.

Accessing the button resources like this (given the IDs of the buttons in XML are button1, button2 and so on):

for (String b : splited){
    findViewById(getResources().getIdentifier("button" + b, "id", getPackageName()))
        .setBackgroundColor(Color.RED);
}

edited Aug 21, 2014 at 9:33

answered Aug 21, 2014 at 7:54

0101100101

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1 Comment

user3947486 Over a year ago

Eclipse said getResources cannot be resolved. I have tried to import but there is no import available. What should I do?

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