.NET杂项

当 Combox的SelectIndex设置的值超出子项后，index会自动切换成默认值-1，并不会抛出异常.

TextBox的Text默认值是空字符串不是null。

Assembly.GetCallingAssembly()和Assembly.GetExecutingAssembly()的区别。后者是指写这行代码的程序集，也就是当前程序集，值是固定的唯一的。前者是指引用这行代码所在的程序集，调用这行代码所属的类，方法的程序集，值可能是自身程序集，也可能是其他程序集，可能值理论上无限个。

// Assembly FirstAssembly
using System;
using System.Reflection;
using System.Runtime.CompilerServices;

namespace FirstAssembly
{
    public class InFirstAssembly
    {
        public static void Main()
        {
            FirstMethod();
            SecondAssembly.InSecondAssembly.OtherMethod();
        }

        [MethodImpl(MethodImplOptions.NoInlining)]
        public static void FirstMethod()
        {
            Console.WriteLine("FirstMethod called from: " + Assembly.GetCallingAssembly().FullName);
        }
    }
}

// Assembly SecondAssembly
namespace SecondAssembly
{
    class InSecondAssembly
    {
        [MethodImpl(MethodImplOptions.NoInlining)]
        public static void OtherMethod()
        {
            Console.WriteLine("OtherMethod executing assembly: " + Assembly.GetExecutingAssembly().FullName);
            Console.WriteLine("OtherMethod called from: " + Assembly.GetCallingAssembly().FullName);
        }
    }
}
// The example produces output like the following:
// "FirstMethod called from: FirstAssembly, Version=0.0.0.0, Culture=neutral, PublicKeyToken=null"
// "OtherMethod executing assembly: SecondAssembly, Version=0.0.0.0, Culture=neutral, PublicKeyToken=null"
// "OtherMethod called from: FirstAssembly, Version=0.0.0.0, Culture=neutral, PublicKeyToken=null"