Change background based on text in TextView in Android

Question

I'm trying to get the backgound of the layout to change based on what's in a textview. I know how to set the background in Java:

mainbg.setBackgroundResource(R.drawable.erburrows);

but if I wrap that call in an if statement, nothing happens. There are no error flags or anything, it just doesn't display anything in the background. Here's the code I'm using:

        //--- BACKGROUND CHANGE ---
    String tvString = showBook.getText().toString();
    bookDisp.setText(tvString);
    View mainbg = bgview.getRootView();
    if(bookDisp.equals("Green Eggs")){
    mainbg.setBackgroundResource(R.drawable.seuss);
    }else if (bookDisp.equals("Tarzan")){
        mainbg.setBackgroundResource(R.drawable.erburrows);
    }

    //--- END BACKGROUND CHANGE ---

Any idea why it doesn't work?

Answer 1

You are setting the text on bookDisp (I guess that this is the TextView ) and then instead of using the text from that TextView you do a compare between the TextView object( bookDisp ) and the test String that will fail. You'll probably want to do:

if(tvString.equals("Green Eggs")){
    mainbg.setBackgroundResource(R.drawable.seuss);
    }else if (tvString.equals("Tarzan")){
        mainbg.setBackgroundResource(R.drawable.erburrows);
    }
//...

if tvString is the text from the target TextView or get the string:

bookDisp.getText().toString()

Answer 2

尝试：

mainbg.setBackgroundDrawable(getResources().getDrawable(R.drawable.erburrows));

Answer 3

if(bookDisp.equals("Green Eggs")){
    mainbg.setBackgroundResource(R.drawable.seuss);
    }else if (bookDisp.equals("Tarzan")){
        mainbg.setBackgroundResource(R.drawable.erburrows);
    }

replace the above code with below and try:::

if(bookDisp.getText().toString().equals("Green Eggs")){
    mainbg.setBackgroundResource(R.drawable.seuss);
    }else if (bookDisp.getText().toString().equals("Tarzan")){
        mainbg.setBackgroundResource(R.drawable.erburrows);
    }