一個將阿拉伯數字轉換成中文大寫的好算法

//加到類的定義部分
private static string[] cstr={"零","壹","貳","三","肆", "伍", "陸","柒","捌","玖"};
private static string[] wstr={"","","拾","佰","仟","萬","拾","佰","仟","億","拾","佰","仟"};
//數字必須在12位整數以內的字符串
//調用方式如：Label1.Text=ConvertInt("數字字符串");

public string ConvertInt(string str)
{
int len=str.Length;
int i;
string tmpstr,rstr;
rstr="";
for(i=1;i<=len;i++)
{
tmpstr=str.Substring(len-i,1);
rstr=string.Concat(cstr[Int32.Parse(tmpstr)]+wstr[i],rstr);
}
rstr=rstr.Replace("拾零","拾");
rstr=rstr.Replace("零拾","零");
rstr=rstr.Replace("零佰","零");
rstr=rstr.Replace("零仟","零");
rstr=rstr.Replace("零萬","萬");
for(i=1;i<=6;i++)
rstr=rstr.Replace("零零","零");
rstr=rstr.Replace("零萬","零");
rstr=rstr.Replace("零億","億");
rstr=rstr.Replace("零零","零");
rstr+="圓整";
return rstr;
}