网格布局 GridLayout

网格布局，按照行、列组成一个个网格

界面代码：

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

    <TextView
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_columnSpan="4"
        android:textSize="50sp"
        android:layout_marginLeft="2pt"
        android:layout_marginRight="2pt"
        android:padding="3pt"
        android:layout_gravity="right"
        android:background="#eee"
        android:textColor="#000"
        android:text="0"
    />
    <Button
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_columnSpan="4"
            android:text="清除"
    />

</GridLayout>

我们用xml添加两个组件，占4列，然后用代码添加其他16个组件

package com.example.gridlayout

import android.support.v7.app.AppCompatActivity
import android.os.Bundle
import android.view.Gravity
import android.widget.Button
import android.widget.GridLayout

class MainActivity : AppCompatActivity() {

    private var chars = arrayOf("7","8","9","/",
        "4","5","6","x",
        "1","2","3","--",
        ".","0","=","+")
    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_main)

        var gridLayout = findViewById<GridLayout>(R.id.root)
        for(i in chars.indices)
        {
            val bn = Button(this)
            bn.text = chars[i]
            //设置按钮字号大小
            bn.textSize = 40F
            //设置按钮空白区域
            bn.setPadding(5,35,5,35)
            //指定按钮所在的行
            val rowSpec = GridLayout.spec(i/4+2)
            //指定所在的列
            val columnSpec = GridLayout.spec(i%4)
            val params = GridLayout.LayoutParams(rowSpec,columnSpec)
            //指定组件占满父容器
            params.setGravity(Gravity.FILL)
            gridLayout.addView(bn,params)
        }
    }
}