试图创建一个尝试捕获异常，如果无法找到一个文件与旧文件的值的新文件被加载而不是

Question

我有一个try catch异常，如果dict.csv文件不能找到一个messagebox将出现并且将创建一个名为newdict.csv的新文件 - 如何将dict.csv文件的旧值加载到新文件中？

这些值是用户名和密码的列表？

try //checks for existing dict.csv file and reads it for key and value and checks against credentials 
     { 

      var data = File.ReadAllLines(@"C:\Users\Scott\Documents\dict.csv");//Reads all contents of a file and then closes the file once its been read 
      foreach (var login in data) 
      { 
       var parts = login.Split(',');//creates a variable called data and loads it with the dict.csv file 
       Credentials.Add(parts[0].Trim(), parts[1].Trim());//splites the key and value into [0] and [1] and trim removes leading and white space and applies "," 
      } 
     } 
     catch (FileNotFoundException)//How do I load the newdict.csv with values of dict.csv? 
     { 
      MessageBox.Show("dict.csv file does not exist! Creating new file called newdict.csv", "Error!", MessageBoxButtons.OK, MessageBoxIcon.Exclamation); 
      using (StreamWriter writer = File.AppendText(@"C:\Users\Scott\Documents\newdict.csv ")) 
      Credentials.Add("bob2", "password");       
      Credentials.Add("user", "pass"); 
     } 

Answer 1

我想你会更好，如果你使用：

string[] newCredentials, data, parts; 
if (!File.Exists(@"C:\Users\Scott\Documents\dict.csv")) 
{ 
    //create .csv file 
    newCredentials = new string[2]; 
    newCredentials[0] = "Bob2,password"; 
    newCredentials[1] = "user,pass"; 
    File.WriteAllLines(@"C:\Users\Scott\Documents\newdict.csv", newCredentials)) 
    Credentials.Add("bob2", "password");       
    Credentials.Add("user", "pass"); 
} 
else 
{ 
    data = File.ReadAllLines(@"C:\Users\Scott\Documents\dict.csv"); 
    foreach(string login in data) 
    { 
     parts = login.Split(','); 
     Credentials.Add(parts[0].Trim(), parts[1].Trim()); 
    } 
}