计算器。。。GridLayout

---------------------------------------MainActivity.java---------------------------------

package com.example.gridlayout;


import android.support.v7.app.ActionBarActivity;
import android.os.Bundle;
import android.view.Gravity;
import android.view.Menu;
import android.view.MenuItem;
import android.widget.Button;
import android.widget.GridLayout;


public class MainActivity extends ActionBarActivity {


GridLayout gridLayout;
String []chars = 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);
gridLayout = (GridLayout) findViewById(R.id.root);
for(int i = 0; i < chars.length; ++i) {
Button button = new Button(this);
button.setText(chars[i]);
//设置按钮的大小
button.setTextSize(40);
//指定该组件所在的行
GridLayout.Spec rowSpec = GridLayout.spec(i / 4 + 2);
//指定该组件所在的列
GridLayout.Spec columnSpec = GridLayout.spec(i % 4);
GridLayout.LayoutParams params = new GridLayout.LayoutParams(rowSpec, columnSpec);
//指定该组件占满父容器
params.setGravity(Gravity.FILL);
gridLayout.addView(button, params);

}
}


}

----------------------------------------------activity_main.xml---------------------------------------

<?xml version="1.0" encoding="utf-8"?>
<GridLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent" 
    android:rowCount="6"
    android:columnCount="4"
    android:id="@+id/root"
    >


    <!-- 横跨4列的文本框 -->
    <TextView
        android:id="@+id/textView1"
   android:layout_width="fill_parent"
   android:layout_height="wrap_content" 
   android:layout_columnSpan="4"
   android:textSize="50sp"
   android:layout_marginLeft="4px"
   android:layout_marginRight="4px"
   android:padding="5px"
   
        android:layout_gravity="right"
        android:background="#eee"
        android:textColor="#000"
        android:text="0" />
    


    <!-- 横跨4列的按钮 -->
    <Button
        android:id="@+id/button1"
   android:layout_width="fill_parent"
   android:layout_height="wrap_content" 
   android:layout_columnSpan="4"
        android:text="清除" />

</GridLayout>