C＃字典找不到字符串鍵

Question

我會生氣嗎？爲什麼這會返回一個異常！？爲什麼找不到鑰匙？顯然是在那裏！

public class Spanning { 
    Dictionary<string, City> graph = new Dictionary<string, City>(); 

    public static void Main(string[] args) { 
     new Spanning().Parse("file.in"); 
    } 

    public void Parse(string f) { 
     string[] citySeparator = new string[] {"--"}; 
     using (StreamReader reader = new StreamReader(f)) { 
      string line; 
      while((line = reader.ReadLine()) != null) { 
       if (!line.Contains("--")) { 
        graph[line] = new City {name = line.Substring(0, line.Length - 1)}; 
       } else { 
        string[] split = line.Split(citySeparator, StringSplitOptions.None); 
        City city1 = graph[split[0]]; 
       } 
      } 
     } 
    } 

    class City { 
     Dictionary<City, int> links = new Dictionary<City, int>(); 
     public string name; 

     public override string ToString() { 
      return name; 
     } 
    } 
} 

輸入文件只包含兩行：

"San Diego" 
"San Diego"--"San Antonio" [1319] 

Answer 1

文件

"San Diego" 

有最後"和換行之間的空格字符的第一行。

要麼收拾你輸入的文件，或者使用Trim()擺脫它：

... 
if (!line.Contains("--")) { 
    graph[line.Trim()] = new City {name = line.Substring(0, line.Length - 1)}; 
...