For example I want to add 3 buttons on screen: one align left, one align center, last one align right.
How can I set their layout in code, not in xml?
For example I want to add 3 buttons on screen: one align left, one align center, last one align right.
How can I set their layout in code, not in xml?
Just a basic example:
RelativeLayout.LayoutParams params = new RelativeLayout.LayoutParams(RelativeLayout.LayoutParams.WRAP_CONTENT, RelativeLayout.LayoutParams.WRAP_CONTENT);
params.addRule(RelativeLayout.ALIGN_PARENT_LEFT, RelativeLayout.TRUE);
Button button1;
button1.setLayoutParams(params);
params = new RelativeLayout.LayoutParams(RelativeLayout.LayoutParams.WRAP_CONTENT, RelativeLayout.LayoutParams.WRAP_CONTENT);
params.addRule(RelativeLayout.RIGHT_OF, button1.getId());
Button button2;
button2.setLayoutParams(params);
As you can see, this is what you have to do:
RelativeLayout.LayoutParams object.addRule(int) or addRule(int, int) to set the rules. The first method is used to add rules that don't require values. 
    
        RelativeLayout layout = new RelativeLayout(this);
    RelativeLayout.LayoutParams labelLayoutParams = new RelativeLayout.LayoutParams(
            LayoutParams.FILL_PARENT, LayoutParams.FILL_PARENT);
    layout.setLayoutParams(labelLayoutParams);
   // If you want to add some controls in this Relative Layout
    labelLayoutParams = new RelativeLayout.LayoutParams(
            LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT);
    labelLayoutParams.addRule(RelativeLayout.CENTER_IN_PARENT);
    ImageView mImage = new ImageView(this);
    mImage.setBackgroundResource(R.drawable.popupnew_bg);        
    layout.addView(mImage,labelLayoutParams);
    setContentView(layout);
 
    
     
    
    Something like this..
 RelativeLayout linearLayout = (RelativeLayout) findViewById(R.id.widget43);
                // ListView listView = (ListView) findViewById(R.id.ListView01);
                LayoutInflater inflater = (LayoutInflater) this
                        .getSystemService(Context.LAYOUT_INFLATER_SERVICE);
                // View footer = inflater.inflate(R.layout.footer, null);
                View footer = LayoutInflater.from(this).inflate(R.layout.footer,
                        null);
                final RelativeLayout.LayoutParams layoutParams = new RelativeLayout.LayoutParams(
                        RelativeLayout.LayoutParams.FILL_PARENT,
                        RelativeLayout.LayoutParams.FILL_PARENT);
                layoutParams.addRule(RelativeLayout.ALIGN_PARENT_BOTTOM, 1);
footer.setLayoutParams(layoutParams);
 
    
    How about you just pull the layout params from the view itself if you created it.
$((RelativeLayout)findViewById(R.id.imageButton1)).getLayoutParams();
 
    
    I hope the below code will help. It will create an EditText and a Log In button. Both placed relatively. All done in MainActivity.java.
package com.example.atul.allison;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.widget.RelativeLayout;
import android.widget.Button;
import android.graphics.Color;
import android.widget.EditText;
import android.content.res.Resources;
import android.util.TypedValue;     
    public class MainActivity extends AppCompatActivity {
        @Override
        protected void onCreate(Bundle savedInstanceState) {
            super.onCreate(savedInstanceState);
            //Layout
            RelativeLayout atulsLayout = new RelativeLayout(this);
            atulsLayout.setBackgroundColor(Color.GREEN);
            //Button
            Button redButton = new Button(this);
            redButton.setText("Log In");
            redButton.setBackgroundColor(Color.RED);
            //Username input
            EditText username =  new EditText(this);
            redButton.setId(1);
            username.setId(2);
            RelativeLayout.LayoutParams buttonDetails= new RelativeLayout.LayoutParams(
                    RelativeLayout.LayoutParams.WRAP_CONTENT,
                    RelativeLayout.LayoutParams.WRAP_CONTENT
            );
            RelativeLayout.LayoutParams usernameDetails= new RelativeLayout.LayoutParams(
                    RelativeLayout.LayoutParams.WRAP_CONTENT,
                    RelativeLayout.LayoutParams.WRAP_CONTENT
            );
            //give rules to position widgets
            usernameDetails.addRule(RelativeLayout.ABOVE,redButton.getId());
            usernameDetails.addRule(RelativeLayout.CENTER_HORIZONTAL);
            usernameDetails.setMargins(0,0,0,50);
            buttonDetails.addRule(RelativeLayout.CENTER_HORIZONTAL);
            buttonDetails.addRule(RelativeLayout.CENTER_VERTICAL);
            Resources r = getResources();
            int px = (int) TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_DIP, 200,r.getDisplayMetrics());
            username.setWidth(px);
            //Add widget to layout(button is now a child of layout)
            atulsLayout.addView(redButton,buttonDetails);
            atulsLayout.addView(username,usernameDetails);
            //Set these activities content/display to this view
            setContentView(atulsLayout);
        }
    }
