c#时间格式转换汉字大写

string[] c = new string[]{ "零", "壹", "贰", "叁", "肆", "伍", "陆", "柒", "捌", "玖","年","月","日" };

try
{
string input = "2009年9月5日";
StringBuilder str = new StringBuilder();
for (int count = 0; count < input.Length; count++)
{
string temp = input.Substring(count,1);
switch (temp)
{
case "1": str.Append(c[1]); break;
case "2": str.Append(c[2]); break;
case "3": str.Append(c[3]); break;
case "4": str.Append(c[4]); break;
case "5": str.Append(c[5]); break;