Question

I have a question for Android developers. I have a layout with a button (developed programmatically, not with xml) and I want the button to fill the entire layout right now but it currently doesn’t and I’m not sure why, I thought I had everything set up correctly with the gravity of the button and the layout params but here’s what I have. If you can point me in the right direction I would really appreciate it! Thanks.

LinearLayout bottom = new LinearLayout(this);
bottom.setOrientation(LinearLayout.HORIZONTAL);  
LinearLayout.LayoutParams params = new LinearLayout.LayoutParams(LayoutParams.MATCH_PARENT, LayoutParams.WRAP_CONTENT);
params.gravity = Gravity.FILL;
bottom.setLayoutParams(params);  

bottom.setBackgroundColor(Color.BLUE);

Button eqbttn = new Button(this);
eqbttn.setText("=");
eqbttn.setOnClickListener(new OnClickListener(){
    public void onClick(View v) {

    }
});
bottom.addView(eqbttn);

Answer 1

You’ve only applied the MATCH_PARENT size to the LinearLayout. You need to apply it to the button, too.

Button eqbttn = new Button(this);
LinearLayout.LayoutParams eqparams = new LinearLayout.LayoutParams(LayoutParams.MATCH_PARENT, LayoutParams.MATCH_PARENT);
eqbttn.setLayoutParams(eqbttn);
eqbttn.setText("=");
eqbttn.setOnClickListener(new OnClickListener(){
    public void onClick(View v) {

    }
});
bottom.addView(eqbttn);

This will force the button to fill the LAYOUT both vertically and horizontally. If you need the layout itself to take up the whole screen, change its WRAP_CONTENT to MATCH_PARENT as well.

Also, in this case, you do not require the Gravity.FILL layout parameter on the LinearLayout.