android - How to get file read line by line

Question

I have a file containing text in separate line.
I want to display line first, and then if I press a button, the second line should be displayed in the TextView and the first line should disappear. Then, if I press it again, the third line should be displayed and so on.

Should I have to use TextSwitcher or anything else? How can I do that?

Answer 1

You tagged it as "android-assets" so I'm going to assume your file is in the assets folder. Here:

InputStream in;
BufferedReader reader;
String line;
TextView text;

public void onCreate(Bundle savedInstanceState){
    super.onCreate(savedInstanceState);
    setContentView(R.layout.main);
    text = (TextView) findViewById(R.id.textView1);
    in = this.getAssets().open(<your file>);
    reader = new BufferedReader(new InputStreamReader(in));
    line = reader.readLine();

    text.setText(line);
    Button next = (Button) findViewById(R.id.button1);
    next.setOnClickListener(this);
}

public void onClick(View v){
    line = reader.readLine();
    if (line != null){
        text.setText(line);
    } else {
        //you may want to close the file now since there's nothing more to be done here.
    }
}

Give this a try. I haven't been able to verify that it works completely, but I believe this is the general idea you want to follow. Naturally you'll want to replace any R.id.textView1/button1 with the names that you've specified in your layout file.

Also: There is very little error checking here for the sake of space. You will want to check that your asset exists and I'm pretty sure there should be an try/catch block when you open the file for reading.

Edit: Big error, It's not R.layout, it's R.id I have edited my answer to fix the problem.