C# 案例题
1. // # hello world
using System; namespace HelloWorldApplication { class HelloWorld { static void Main(string[] args) { /*my first C# program*/ Console.WriteLine("HelloWorld C#"); Console.ReadKey(); } } }
2. // C# 计算矩形的面积
/*计算矩形的面积 x*y = area*/
using System;
namespace RectangleApplication
{
class Rectangle
{
//成员变量
double X; //chang
double Y; //kuan
public void Accpetdetails()
{
X = 1.2;
Y = 1.3;
}
public double GetArea()
{
return X * Y;
}
public void dispaly()
{
Console.WriteLine("X:{0}", X);
Console.WriteLine("Y:{0}", Y);
Console.WriteLine("Area:{0}", GetArea());
}
class ExecuteRectangle
{
static void Main(string[] args)
{
Rectangle r = new Rectangle();
r.Accpetdetails();
r.dispaly();
Console.ReadLine();
}
}
}
}
3. // 强制类型转换1
/*强制类型装换例子 11520.822 --->>>115200*/
using System;
namespace TypeconversationApplication
{
class ExplicitConversation
{
static void Main(string[] agrs)
{
double d = 115200.822;
int i;
//强制将double类型转换成int 类型
i = (int) d;
Console.WriteLine(i);
Console.ReadKey();
}
}
}4. /*强制类型转换多个例子：
整型、双精度、单精度、布尔类型*/
/*强制类型转换多个例子： 整型、双精度、单精度、布尔类型*/ using System; namespace TypeconversationApplication { class ExplicitConversation { static void Main(string[] agrs) { int i = 75; float f = 53.00f; double d = 115200.82; bool b = true; /*int i; //强制将double类型转换成int 类型 i = (int) d; */ Console.WriteLine(i.ToString()); Console.WriteLine(f.ToString()); Console.WriteLine(d.ToString()); Console.WriteLine(b.ToString()); Console.ReadKey(); } } }5.// C#变量初始化
using System; namespace TypeconversationApplication { class Program { static void Main(string[] args) { short a; int b; double c; /*实际初始化*/ a = 10; b = 20; c = a+b; Console.WriteLine("a ={0},b={1},c={2}", a, b, c); Console.ReadLine(); } } }6./*
常量是使用const关键字来定义的，
下面代码演示了如何在程序中定义和使用常量；*/
using System; public class ConstTest { class SampleClass { public int x; public int y; public const int c1 = 5; public const int c2 = c1 + 5; public SampleClass(int p1, int p2) { x = p1; y = p2; } } static void Main() { SampleClass mC = new SampleClass(11, 22); Console.WriteLine("x = {0}, y = {1}", mC.x, mC.y); Console.WriteLine("c1 = {0}, c2 = {1}", SampleClass.c1, SampleClass.c2); } }7./*
a++ ++a b-- --b 左右自增 、自减
*/
using System; namespace OperatorsAppl { class Program { static void Main(string[] args) { int a = 1; int b; // a++ 先赋值再进行自增运算 b = a++; Console.WriteLine("a = {0}", a); Console.WriteLine("b = {0}", b); Console.ReadLine(); // ++a 先进行自增运算再赋值 a = 1; // 重新初始化 a b = ++a; Console.WriteLine("a = {0}", a); Console.WriteLine("b = {0}", b); Console.ReadLine(); // a-- 先赋值再进行自减运算 a = 1; // 重新初始化 a b = a--; Console.WriteLine("a = {0}", a); Console.WriteLine("b = {0}", b); Console.ReadLine(); // --a 先进行自减运算再赋值 a = 1; // 重新初始化 a b = --a; Console.WriteLine("a = {0}", a); Console.WriteLine("b = {0}", b); Console.ReadLine(); } } }8.//关系运算符
using System; class Program { static void Main(string[] args) { int a = 21; int b = 10; if (a == b) { Console.WriteLine("Line 1 - a 等于 b"); } else { Console.WriteLine("Line 1 - a 不等于 b"); } if (a < b) { Console.WriteLine("Line 2 - a 小于 b"); } else { Console.WriteLine("Line 2 - a 不小于 b"); } if (a > b) { Console.WriteLine("Line 3 - a 大于 b"); } else { Console.WriteLine("Line 3 - a 不大于 b"); } /* 改变 a 和 b 的值 */ a = 5; b = 20; if (a <= b) { Console.WriteLine("Line 4 - a 小于或等于 b"); } if (b >= a) { Console.WriteLine("Line 5 - b 大于或等于 a"); } } }9.//逻辑运算符
using System; class Program { static void Main(string[] args) { int a = 21; int b = 10; if (a == b) { Console.WriteLine("Line 1 - a 等于 b"); } else { Console.WriteLine("Line 1 - a 不等于 b"); } if (a < b) { Console.WriteLine("Line 2 - a 小于 b"); } else { Console.WriteLine("Line 2 - a 不小于 b"); } if (a > b) { Console.WriteLine("Line 3 - a 大于 b"); } else { Console.WriteLine("Line 3 - a 不大于 b"); } /* 改变 a 和 b 的值 */ a = 5; b = 20; if (a <= b) { Console.WriteLine("Line 4 - a 小于或等于 b"); } if (b >= a) { Console.WriteLine("Line 5 - b 大于或等于 a"); } } }10.//if、else if、else逻辑判断嵌套用法
using System; namespace OperatorApp1 { class program { static void Main(string[] args) { //局部变量的定义 int a = 100; //检查布尔的条件 if (a == 50) { Console.WriteLine("a 的值为50"); } else if (a == 60) { Console.WriteLine("a 的值为60"); } else if (a == 70) { Console.WriteLine("a的值为70"); } else { Console.WriteLine("以上条件没有匹配a的值"); } Console.WriteLine("a的值是{0}",a); Console.ReadLine(); } } }11.//运用Switch case的思想 枚举星期一 到星期天的案例
using System; namespace MyApplication { class Program { static void Main(string[] args) { int day = 3; switch (day) { case 1: Console.WriteLine("Monday"); break; case 2: Console.WriteLine("Tuesday"); break; case 3: Console.WriteLine("Wednesday"); break; case 4: Console.WriteLine("Thursday"); break; case 5: Console.WriteLine("Friday"); break; case 6: Console.WriteLine("Saturday"); break; case 7: Console.WriteLine("Sunday"); break; } } } }12.// switch 嵌套的案例
using System; namespace MyApplication { class Program { static void Main(string[] args) { int a = 100; int b = 200; switch (a) { case 100: Console.WriteLine("这是外部Switch的一部分"); switch (b) { case 200: Console.WriteLine("这是内部Switch的一部分"); break; } break; } Console.WriteLine("a的准确值是{0}", a); Console.WriteLine("b的准确值是{0}", b); Console.ReadLine(); } } }13.//while 循环
using System; namespace MyApplication { class Program { static void Main(string[] args) { /*局部变量的定义*/ int a = 10; /*while循环执行*/ while(a<20) { Console.WriteLine(a); a++; } Console.ReadLine(); } } }14. //for循环
using System; namespace MyApplication { class Program { static void Main(string[] args) { /* for 循环执行 */ for (int a = 10; a < 20; a ++) { Console.WriteLine("a 的值： {0}", a); } Console.ReadLine(); } } }15. //0-100以内的质数
using System; namespace Loops { class Program { static void Main(string[] args) { /* 局部变量定义 */ int i, j; for (i = 2; i < 100; i++) { for (j = 2; j <= (i / j); j++) if ((i % j) == 0) break; // 如果找到，则不是质数 if (j > (i / j)) Console.WriteLine("{0} 是质数", i); } Console.ReadLine(); } } }16. //调用方法，取最大值
using System; namespace CaculatorApplication { class NumberManipulator { public int FindMax(int num1, int num2) { /* 局部变量声明 */ int result; if (num1 > num2) result = num1; else result = num2; return result; } static void Main(string[] args) { /* 局部变量定义 */ int a = 100; int b = 200; int ret; NumberManipulator n = new NumberManipulator(); //调用 FindMax 方法 ret = n.FindMax(a, b); Console.WriteLine("最大值是： {0}", ret); Console.ReadLine(); } } }@源于www.runoob.com