下载实例不改动任何能够编译成功，稍加改动无法编译成功。

布局代码：

xmlns:android="http://schemas.android.com/apk/res/android"

android:orientation="vertical"

android:layout_width="fill_parent"

android:layout_height="fill_parent">

android:text="请输入拱高L:"

android:textAppearance="?android:attr/textAppearanceLarge"

android:layout_width="match_parent"

android:layout_height="wrap_content"

android:id="@+id/textView1" />

android:layout_width="match_parent"

android:layout_height="wrap_content"

android:id="@+id/GongGao"

android:text="5" />

android:textAppearance="?android:attr/textAppearanceLarge"

android:layout_width="match_parent"

android:layout_height="wrap_content"

android:id="@+id/TranslatedPhoneWord"

android:text="请输入弦长L" />

android:layout_width="match_parent"

android:layout_height="wrap_content"

android:id="@+id/xianchang" />

android:text="半径R="

android:textAppearance="?android:attr/textAppearanceLarge"

android:layout_width="match_parent"

android:layout_height="50"

android:id="@+id/BanJing" />

android:text="计算半径"

android:layout_width="match_parent"

android:layout_height="wrap_content"

android:id="@+id/JiSuan" />

入口代码：

using System;

using Android.App;

using Android.OS;

using Android.Widget;

namespace Phoneword

{

[Activity(Label = "Phone Word", MainLauncher = true, Icon = "@drawable/icon")]

public class MainActivity : Activity

{

protected override void OnCreate(Bundle savedInstanceState)

{

base.OnCreate(savedInstanceState);

// Set our view from the "main" layout resource

SetContentView(Resource.Layout.Main);

// Get our UI controls from the loaded layout

EditText h = FindViewById(Resource.Id.GongGao);

EditText l = FindViewById(Resource.Id.xianchang);

Button bt = FindViewById(Resource.Id.JiSuan);

TextView tv = FindViewById(Resource.Id.BanJing);

string translatedNumber = string.Empty;

bt.Click += (sender, e) =>

{

try

{

if (double.Parse(h.Text) > 0 && double.Parse(l.Text) > 0)

{

tv.Text = "半径R="+Jisan(double.Parse(h.Text), double.Parse(l.Text));

}

}

catch (Exception ex)

{

tv.Text = ex.ToString();

}

};

}

private string Jisan(double h, double l)

{

return ((h / 2 + l * l / 8 / h).ToString());

}

}

}

其余代码为自动生成。