asp.net 解决下载文件–中文名乱码问题

最近的项目中需要导出Excel 表格，Excel名称是中文的，在IE中下载老是出现中文名称乱码问题，设置 Respone Encoding 无果，最后找到解决方案如下：

public static string ToHexString(string s)
{
char[] chars = s.ToCharArray();
StringBuilder builder = new StringBuilder();
for (int index = 0; index < chars.Length; index++)
{
bool needToEncode = NeedToEncode(chars[index]);
if (needToEncode)
{
string encodedString = ToHexString(chars[index]);
builder.Append(encodedString);
}
else
{
builder.Append(chars[index]);
}
}
return builder.ToString();
}
/// <summary>
/// Determines if the character needs to be encoded.
/// </summary>
/// <param name="chr"></param>
/// <returns></returns>
private static bool NeedToEncode(char chr)
{
string reservedChars = "$-_.+!*'(),@=&";
if (chr > 127)
return true;
if (char.IsLetterOrDigit(chr) || reservedChars.IndexOf(chr) >= 0)
return false;
return true;
}
/// <summary>
/// Encodes a non-US-ASCII character.
/// </summary>
/// <param name="chr"></param>
/// <returns></returns>
private static string ToHexString(char chr)
{
UTF8Encoding utf8 = new UTF8Encoding();
byte[] encodedBytes = utf8.GetBytes(chr.ToString());
StringBuilder builder = new StringBuilder();
for (int index = 0; index < encodedBytes.Length; index++)
{
builder.AppendFormat("%{0}", Convert.ToString(encodedBytes[index], 16));
}
return builder.ToString();
}

使用时，只需调用：
string downloadName = ToHexString(“中文名称”);