Hopes

int int16 int32&&&&int.parse() convert.Int32()

int
-2,147,483,648 到 2,147,483,647
int16
-32768 到 32767
int32
-2,147,483,648 到 2,147,483,647

int = int32

在C#中：
int <==> System.Int32
short <==> System.Int16

long <==> System.Int64

int、int.Parse()、Convert.ToInt32()區別...

        直到自己親自測試了才對他們有所了解，以前就知道用最后面那個，因為怕轉化出錯，所以就用它比較安全。

1.int ：(int)變量，C#默認整型為int32；(不支持bool轉化)

2.int.Parse(string sParameter) 4個構造函數，參數類型只支持string類型；

3.Convert.ToInt32()支持的類型是object；

事例：

using System;
using System.Collections.Generic;
using System.Text;

namespace IntegerSample
{
    public class Program
    {
        private enum eNumber { Man = 1, Woman = 2 };

        private static char cNumber = 'e';
        private static byte btNumber = 12;
        private static long lNumber = 12345;
        private static double dNumber = 12.34d;
        private static decimal dlNumber = 4.5m;
        private static bool bNumber = true;

        private static string str = null;
        private static string str1 = "";
        private static string str2 = "123";
        private static string str3 = "Hello";

        public static void TransformByInt()
        {
            Console.WriteLine("{0} TransformByInt Into {1}", eNumber.Man, (int)eNumber.Man);
            Console.WriteLine("{0} TransformByInt Into {1}", cNumber, (int)cNumber);
            Console.WriteLine("{0} TransformByInt Into {1}", btNumber, (int)btNumber);
            Console.WriteLine("{0} TransformByInt Into {1}", lNumber, (int)lNumber);
            Console.WriteLine("{0} TransformByInt Into {1}", dNumber, (int)dNumber);
            Console.WriteLine("{0} TransformByInt Into {1}", dlNumber, (int)dlNumber);
            //Console.WriteLine("{0} TransformByInt Into {1}", bNumber, (int)bNumber);
            //Console.WriteLine("{0} TransformByInt Into {1}", str1, (int)str);
        }

        // Result: 1
        // Result：101
        // Result: 12
        // Result: 12345
        // Result: 12
        // Result: 4
        // 無法將類型“bool”轉換為“int”
        // 編譯錯誤，不能將string轉化為int

        public static void TransformByIntParse()
        {
            try
            {
                Console.WriteLine("str {0}:", int.Parse(str));
                Console.WriteLine("str1 {0}:", int.Parse(str1));
                Console.WriteLine("str2 {0}:", int.Parse(str2));
                Console.WriteLine("str3 {0}:", int.Parse(str3));
            }
            catch (Exception ex)
            {
                Console.WriteLine(ex.Message.ToString());
            }
        }

        // 值不能為空。
        // 輸入字符串的格式不正確。
        // Result: 123
        // 輸入字符串的格式不正確。

        public static void TransformByConvert()
        {
            try
            {
                Console.WriteLine("{0}", Convert.ToInt32(str));
                Console.WriteLine("{0}", Convert.ToInt32(str1));
                Console.WriteLine("{0}", Convert.ToInt32(str2));
                Console.WriteLine("{0}", Convert.ToInt32(str3));
            }
            catch (Exception ex)
            {
                Console.WriteLine(ex.Message.ToString());
            }
        }

        // Result: 0
        // 輸入字符串的格式不正確。
        // Result: 123
        // 輸入字符串的格式不正確。

        public static void Main(string[] args)
        {
            TransformByInt();
            TransformByIntParse();
            TransformByConvert();
        }
    }
}

ps：C#不會對數據進行四舍五入，只會截取。

posted on 2012-10-24 20:31 ** 閱讀(317) 評論(0)  編輯  收藏