Android: Using findViewById() with a string / in a loop

user573536 picture user573536 · Feb 1, 2011 · Viewed 49.9k times · Source

I'm making an android application, where there is a view composed of hundreds of buttons, each with a specific callback. Now, I'd like to set these callbacks using a loop, instead of having to write hundreds of lines of code (for each one of the buttons).

My question is: How can I use findViewById without statically having to type in each button id? Here is what I would like to do:

    for(int i=0; i<some_value; i++) {
       for(int j=0; j<some_other_value; j++) {
        String buttonID = "btn" + i + "-" + j;
        buttons[i][j] = ((Button) findViewById(R.id.buttonID));
        buttons[i][j].setOnClickListener(this);
       }
    }

Thanks in advance!

Answer

WarrenFaith picture WarrenFaith · Feb 1, 2011

You should use getIdentifier()

for(int i=0; i<some_value; i++) {
   for(int j=0; j<some_other_value; j++) {
    String buttonID = "btn" + i + "-" + j;
    int resID = getResources().getIdentifier(buttonID, "id", getPackageName());
    buttons[i][j] = ((Button) findViewById(resID));
    buttons[i][j].setOnClickListener(this);
   }
}