一、基本控制结构

ISO/ANSI C++中的控制与循环全部适用于C++/CLI。下例展示了C++/CLI控制台程序中的控制循环：

例子：基本循环控制

// Ex3_15.cpp : main project file.
#include "stdafx.h"

using namespace System;

int main(array<System::String ^> ^args)
{
    wchar_t letter;

    Console::Write(L"Enter a letter:");
    letter = Console::Read();

    if(letter>='A')
        if(letter<='Z')
        {
            Console::WriteLine(L"You entered a captial letter.");
            return 0;
        }

    if(letter>='a')
        if(letter<='z')
        {
            Console::WriteLine(L"You entered a small letter.");
            return 0;
        }

    Console::WriteLine(L"You did not enter a letter.");
    return 0;
}

letter被声明为wchar_t类型，映射为C++/CLI中的System::Char类型，它具有一些特殊的功能，其中包括将字符代码转换为大写和小写的函数：Char::ToUpper（）和Char::ToLower()，被转换的函数作为参数被传递给它:

wchar_t uppercaseLetter = Char::ToUpper(letter);

此外还包括检测字母是否大写或小写的函数:IsUpper()和IsLower()，因此上例可改为

wchar_t letter; 
wchar_t upper; 

Console::Write(L"Enter a letter:"); 
letter = Console::Read(); 
upper = Char::ToUpper(letter); 

if(upper>='A' && upper<='Z') 
    Console::WriteLine(L"You entered a {0} letter.", Char::IsUpper(letter) ? "Capital":"Small"); 
else 
    Console::WriteLine(L"You entered a small letter.");

Console::ReadKey()函数用于测试按键，并将结果存储在ConsoleKeyInfo类对象里。该类有3个可访问属性用于帮助确定被按下的键是哪个或哪些键。属性Key识别被按下的键是哪个，属性KeyChar是被按键的Unicode字符码，属性Modifiers表示Shift,Alt,Ctrl键的按位组合，它是定义在System命名空间中的枚举类型ConsoleModifiers的常量，包括Shift\Alt\Control。

应该注意的是，在C++/CLI中枚举常量在用作数值之前必须被显示的强制转换为值类型（整数类型）

例子：使用Console::ReadKey()函数

// Ex3_16.cpp : main project file.

#include "stdafx.h"

using namespace System;

int main(array<System::String ^> ^args)
{
	ConsoleKeyInfo keyPress;

	Console::WriteLine(L"Press a key combination - press Escape to quit.");
	do{
		keyPress = Console::ReadKey(true);
		Console::Write(L"You pressed");
		if(safe_cast<int>(keyPress.Modifiers)>0)
			Console::Write(L" {0}", keyPress.Modifiers);
		Console::WriteLine(L" {0} which is the {1} character", keyPress.Key, keyPress.KeyChar);
	}while(keyPress.Key != ConsoleKey::Escape);
    return 0;
}

该程序的输入示例如下：

Press a key combination - press Escape to quit.
You pressed Enter which is the  character
You pressed Spacebar which is the   character
You pressed Spacebar which is the   character

从输出中可以看出，当不只一个键被按下时，用一条语句就可以得到所有的键。这是因为Modifiers枚举类型是用FlagsAttribute属性定义的，该属性表明这种枚举类型是一组唯一的位标志。这使得该枚举类型的变量可以由若干与在一起的标志位组成，而Write()或WriteLine()函数可以识别并输出各标志位。

二、for each循环

以例子开始

// Ex3_17.cpp : main project file.

#include "stdafx.h"

using namespace System;

int main(array<System::String ^> ^args)
{
	int volwels = 0;
	int consonants = 0;
	String^ proverb = L"A nod is as good as a wink to a blind horse.";

	for each(wchar_t ch in proverb)
	{
		if(Char::IsLetter(ch))
		{
			ch = Char::ToLower(ch);
			switch(ch)
			{
			case 'a': case 'e': case 'i': case 'o': case 'u':
				++volwels;
				break;

			default:
				++consonants;
				break;
			}
		}
	}

	Console::WriteLine(proverb);
	Console::WriteLine(L"The proverb contains {0} volwels and {1} consonants.",
		volwels, consonants);
    return 0;
}

输出为：

A nod is as good as a wink to a blind horse. 
The proverb contains 14 volwels and 18 consanants. 

注意：由于proverb字符串中的字符都是Unicode字符，因此用wchar_t（映射为Char类型）类型的变量来存储这些字符。变量ch为循环内的局部变量。