【 tulaoshi.com - ASP.NET 】
                             
                             using System.Text;
private string AddNumber(string numA, string numB)
 {
 int lenA=0, lenB=0;
 int lenI=0, intTen=0;
 int intA=0, intB=0; 
 StringBuilder result=new StringBuilder("");
 lenA=numA.Length;
 lenB=numB.Length;
 if(lenA>lenB)
 lenI=lenA;
 else
 lenI=lenB;
 for(int i=0; i
 {
 if(i intA=Convert.ToInt16(numA.Substring(lenA-i-1,1));
 else
 intA=0;
 if(i intB=Convert.ToInt16(numB.Substring(lenB-i-1,1));
 else
 intB=0;
 int temp=intA+intB+intTen;
 result.Insert(0,Convert.ToString((int)temp%10));
 intTen=(int)temp /10;
 }
 if(intTen>0)
 result.Insert(0,Convert.ToString(intTen));
 return result.ToString();
 }
 private string MultiNum(string NumA, string NumB)
 {
 int lenA=0, lenB=0;
 int lenI=0;
 string result="0";
 string AddResult="0";
 int Dig=0;
 lenA=NumA.Length;
 lenB=NumB.Length;
 if(lenA>lenB)
 {
 lenI=lenB;
 for(int i=0; i {
 AddResult="0";
 Dig=Convert.ToInt16(NumB.Substring(lenB-i-1,1));
 for(int j=0; j AddResult=AddNumber(NumA,AddResult);
 for(int k=0; k AddResult=AddResult + "0";
 result=AddNumber(AddResult,result);
 }
 }
 else
 {
 lenI=lenA;
 for(int i=0; i {
 AddResult="0";
 Dig=Convert.ToInt16(NumA.Substring(lenA-i-1,1));
 for(int j=0; j AddResult=AddNumber(NumB,AddResult);
 for(int k=0; k AddResult=AddResult + "0";
 result=AddNumber(AddResult,result);
 }
 } 
 return result;
 }
 private void button2_Click(object sender, System.EventArgs e)
 {
 DateTime dtm1=DateTime.Now;
 Console.WriteLine(AddNumber("1225225236523456889","1255625622452552"));
 Console.WriteLine(dtm1.Millisecond + " " + DateTime.Now.Millisecond ); 
 }
 private void button3_Click(object sender, System.EventArgs e)
 {
 DateTime dtm1=DateTime.Now;
 string test="1";
 test=MultiNum("453123123156341231651231563121563151213513422","1254564231541321541385435453453124563131541534313543");
 Console.WriteLine(test);
 Console.WriteLine(dtm1.Millisecond + " " + DateTime.Now.Millisecond ); }