if (name == null || name == "")
    throw new ArgumentException("name is null or empty");

另一个看起来像这样的片段：

if (!File.Exists(name))
{
    throw new Exception("File does not exist!");
}

我只是想知道不同之处是什么以及为什么一个在另一个之上使用

MSDN很好地描述了它：

When you have to throw an exception,you can often use an existing exception type in the .NET Framework instead of implementing a custom exception. You should use a standard exception type under these two conditions:

• You are throwing an exception that is caused by a usage error (that is,by an error in program logic made by the developer who is calling your method). Typically,you would throw an exception such as ArgumentException,ArgumentNullException,InvalidOperationException,or NotSupportedException. The string you supply to the exception object’s constructor when instantiating the exception object should describe the error so that the developer can fix it. For more information,see the Message property.
• You are handling an error that can be communicated to the caller with an existing .NET Framework exception. You should throw the most derived exception possible. For example,if a method requires an argument to be a valid member of an enumeration type,you should throw an InvalidEnumArgumentException (the most derived class) rather than an ArgumentException.

第一种方法

static void Main(string[] args) 
{
    try
    {
        System.Windows.Forms.Application.Run(mainform);
    }
    catch (Exception ex)
    {
        // Log error and display error message
    }
}

第二种方法

static void Main(string[] args) 
{
    System.Windows.Forms.Application.ThreadException += 
        new ThreadExceptionEventHandler(Application_ThreadException);
    System.Windows.Forms.Application.Run(mainform);
}

static void Application_ThreadException(object sender,ThreadExceptionEventArgs e)
{
    // Log error and display error message
}

处理ThreadException事件会给你一些try / catch没有的东西吗？

在try / catch设计中,表单中的第一个未处理的异常将导致应用程序停止.您将捕获异常,但应用程序将结束.

请注意,在某些情况下还会引发一个AppDomain.UnhandledException事件(主窗口表单线程以外的线程中未处理的异常并且没有捕获ThreadException),所有这些都是对您的应用程序非常不利的消息.