将扩展ASCII转换为UTF8

如何解决将扩展ASCII转换为UTF8

我被要求解决文件中的编码问题。 预期使用UTF8，但实际上使用扩展ASCII。

结果是一个文件，其内容如下：

巴西利亚； Eletrônicos eInformáticaCâmeras eAcessóriosmásica

实际上应该是：

巴西利亚电子信箱卡梅拉斯州Acessóriosmúsica

我用以下代码解决了它：

private static string FixEncodingIssues(string str)
        {
            string fixedStr = str;

            foreach (keyvaluePair<string,string> pair in encodingErrosDic)
                fixedStr = fixedStr.Replace(pair.Key,pair.Value);
            
            return fixedStr;
        }

        private static Dictionary<string,string> encodingErrosDic = new Dictionary<string,string>()
        {
            { "Ã","Ã" },{ "Ã\x81","Á" },{ "À","À" },{ "Â","Â" },{ "Ä","Ä" },{ "Ã…","Å" },{ "Ç","Ç" },{ "È","È" },{ "É","É" },{ "Ê","Ê" },{ "Ë","Ë" },{ "ÃŒ","Ì" },{ "Ã\x8D","Í" },{ "ÃŽ","Î" },{ "Ã\x8F","Ï" },{ "Ã\x90","Ð" },{ "Ñ","Ñ" },{ "Ã’","Ò"},{ "Ó","Ó" },{ "Ô","Ô" },{ "Õ","Õ" },{ "Ö","Ö" },{ "×","×" },{ "Ø","Ø" },{ "Ù","Ù" },{ "Ú","Ú" },{ "Û","Û" },{ "Ãœ","Ü" },{ "Ã\x9D","Ý" },{ "Ã\xA0","à" },{ "á","á" },{ "â","â" },{ "ã","ã" },{ "ä","ä" },{ "Ã¥","å" },{ "æ","æ" },{ "ç","ç" },{ "è","è" },{ "é","é" },{ "ê","ê"},{ "ë","ë" },{ "ì","ì" },{ "î","î" },{ "ï","ï" },{ "Ã\xAD","í" },{ "ð","ð" },{ "ñ","ñ" },{ "ò","ò" },{ "ó","ó" },{ "ô","ô" },{ "õ","õ" },{ "ö","ö" },{ "ø","ø" },{ "ù","ù" },{ "ú","ú" },{ "û","û" },{ "ü","ü" },{ "ý","ý" }
        };

我想知道是否有更好的方法来解决此问题。我觉得我的解决方案太粗糙了，不适用于字典中未列出的字节。我想知道是否有一个更干净的解决方案，不涉及列出所有扩展案例，并用等效的UTF8值替换它们。