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()区别...
       
直到自己亲自测试了才对他们有所了解,以前就知道用最后面那个,因为怕转化出错,所以就用它比较安全。
1.int :(int)变量,C#默认整型为int32;(不支持bool转化)
2.int.Parse(string sParameter) 4个构造函数,参数类型只支持string类型;
3.Convert.ToInt32()支持的类型是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
        // 无法将类型“bool”转换为“int”
        // 编译错误,不能将string转化为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());
            }
        }
       
// 值不能为空。
        // 输入字符串的格式不正确。
        // Result: 123
        // 输入字符串的格式不正确。
       
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
        // 输入字符串的格式不正确。
        // Result: 123
        // 输入字符串的格式不正确。
       
public static void Main(string[] args)
        {
           
TransformByInt();
           
TransformByIntParse();
           
TransformByConvert();
        }
    }
}
ps:C#不会对数据进行四舍五入,只会截取。