I've seen this question a lot on the internet, but all solutions didn't work for me..
So this is the problem. I want a button that has 50% width of the screen (that works fine).
But now I want it to have the same height the as the width.
Somehow this doesn't work:
Button button1 = (Button) findViewById(R.id.button1);
int btnSize = button1.getLayoutParams().width;
button1.setLayoutParams(new LinearLayout.LayoutParams(btnSize, btnSize));
See this for the code:
Activity1.java:
package nl.jesse.project1;
import android.app.Activity;
import android.os.Bundle;
import android.view.View;
import android.view.Menu;
import android.view.MenuItem;
import android.widget.Button;
import android.widget.LinearLayout;
public class Activity1 extends Activity {
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_activity1);
        Button button1 = (Button) findViewById(R.id.button1);
        int btnSize = button1.getLayoutParams().width;
        System.out.println(btnSize);
        //button1.setLayoutParams(new LinearLayout.LayoutParams(btnSize, btnSize));
    }
    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.menu_activity1, menu);
        return true;
    }
    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        // Handle action bar item clicks here. The action bar will
        // automatically handle clicks on the Home/Up button, so long
        // as you specify a parent activity in AndroidManifest.xml.
        int id = item.getItemId();
        //noinspection SimplifiableIfStatement
        if (id == R.id.action_settings) {
            return true;
        }
        return super.onOptionsItemSelected(item);
    }
}
Activity_activity1.xml:
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Activity1"
    android:weightSum="1.0" >
    <Button
        android:layout_height="wrap_content"
        android:layout_weight=".5"
        android:layout_width="0dip"
        android:text="@string/button1"
        android:id="@+id/button1" />
</LinearLayout>
I've already tried this and parts of it, without success.
- How to set same width and height of a button
 - ImageView - have height match width?
 - Set same height as width at a ToggleButton
 - Layout width equal height
 
So what am I doing wrong?