Надеюсь, приведенный ниже код поможет.Это создаст EditText и кнопку входа.Оба размещены относительно.Все сделано в 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);
}
}