C#用字典中的字符键值替换字符串中的所有字符

Question

嗨,我有这本词典

Dictionary<char, string> keys = new Dictionary<char, string>();
keys.Add("a", "23");
keys.Add("A", "95");
keys.Add("d", "12");
keys.Add("D", "69");

例如这个字符串

string text = "Dad";

我想用字典键和值加密字符串!
最终加密的字符串将是:
692312

有谁可以帮忙？!

Answer 1

我建议使用Linq和string.Concat:

// Dictionary<string, string> - actual keys are strings
Dictionary<string, string> keys = new Dictionary<string, string>();

keys.Add("a", "23");
keys.Add("A", "95");
keys.Add("d", "12");
keys.Add("D", "69");

string result = string.Concat(text.Select(c => keys[c.ToString()]));

更好的设计是声明keys为Dictionary<char, string>:

Dictionary<char, string> keys = new Dictionary<char, string>() {
  {'a', "23"},
  {'A', "95"},
  {'d', "12"},
  {'D', "69"},    
};

...

string result = string.Concat(text.Select(c => keys[c]));

编辑:证明每个字符都被编码为固定长度的字符串(2在示例中),它很容易解码:

Dictionary<string, char> decode = keys
  .ToDictionary(pair => pair.Value, pair => pair.Key);

int fixedSize = decode.First().Key.Length;

string decoded = string.Concat(Enumerable
  .Range(0, result.Length / fixedSize)
  .Select(i => decode[result.Substring(i * fixedSize, fixedSize)]));