package com.example.gridlayout;import android.app.Activity;import android.os.Bundle;import android.view.Gravity;import android.widget.Button;import android.widget.GridLayout;public class MainGrid extends Activity {    GridLayout grd;    String[] chas=new String[]            {              "7","8","9","*"              ,"4","5","6","/"              ,"1","2","3","+"              ,"0",".","=","-"                        };        @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);       setContentView(R.layout.activity_main_grid);        grd=(GridLayout)findViewById(R.id.root);        for(int i=0;i