Dictionary.ContainsKey甚至认为密钥存在时返回false

Question

我有一段代码如下：

IDictionary<string, string> dictionary = new Dictionary<string, string>(){
        { "de-DE", "German"},
        { "en‐GB", "English"},
        { "en‐US", "English"},
        { "es‐ES", "Spanish"},
        { "es‐MX", "Spanish"},
        { "fr‐CA", "French"},
        { "fr‐FR", "French"},
        { "hu‐HU", "Hungarian"},
        { "pl‐PL", "Polish"},
        { "pt‐PT", "Portuguese"},
        { "nl‐NL", "Dutch"},
        { "nb‐NO", "Norwegian"},
        { "sv‐SE", "Swedish"},
        { "it‐IT", "Italian"},
};
bool check = dictionary.ContainsKey("en-US");
Console.WriteLine(check);

check返回false 。 有人可以帮忙解释一下吗？

Answer 1

你的破折号不一样。在Notepad++中查看文本的样子（当您需要调试与此类相关的字符时很有用）：

将短划线替换为实际的-，the code works as expected。

修改

谢谢，@斯科特张伯伦为。net fiddle that highlights the character differences。

Answer 2

正如已经指出的你的破折号不是同一个。我已向您的Dictionary添加了另一项项目，该项目可为您提供预期结果，并通过IL比较基础Ildasm以了解其中的差异：

{ "en‐US", "English"},
{ "en-US", "English2"},

和

IL_002d:  nop
IL_002e:  dup
IL_002f:  ldstr      bytearray (65 00 6E 00 10 20 55 00 53 00 )                   // e.n.. U.S.
IL_0034:  ldstr      "English"
IL_0039:  callvirt   instance void class [mscorlib]System.Collections.Generic.Dictionary`2<string,string>::Add(!0,
                                                                                                                 !1)
IL_003e:  nop
IL_003f:  dup
IL_0040:  ldstr      "en-US"
IL_0045:  ldstr      "English2"
IL_004a:  callvirt   instance void class [mscorlib]System.Collections.Generic.Dictionary`2<string,string>::Add(!0,
                                                                                                                 !1)