C＃使用强制转换将Int64转换为String

Question

How do you convert an integer to a string? It works the other way around but not this way.

string message
Int64 message2;
message2 = (Int64)message[0];

If the message is "hello", the output is 104 as a number;

If I do

string message3 = (string)message2;

I get an error saying that you cant convert a long to a string. Why is this. The method .ToString() does not work because it converts just the number to a string so it will still show as "104". Same with Convert.ToString(). How do I make it say "hello" again from 104? In C++ it allows you to cast such methods but not in C#

Answer 1

message[0] gives first letter from string as char , so you're casting char to long , not string to long .

Try casting it back to char again and then concatenate all chars to get entire string.

Answer 2

ToString() is working exactly correctly. Your error is in the conversion to integer.

How exactly do you expect to store a string composed of non-numeric digits in a long? You might be interested in BitConverter , if you want to treat numbers as byte arrays.

If you want to convert a numeric ASCII code to a string, try

((char)value).ToString()

Answer 3

Another alternative approach is using ASCII.GetBytes method as below

string msg1 ="hello";
byte[] ba = System.Text.Encoding.ASCII.GetBytes(msg1);
//ba[0] = 104 
//ba[1] = 101 
//ba[2] = 108 
//ba[3] = 108 
//ba[4] = 111 

string msg2 =System.Text.Encoding.ASCII.GetString(ba);
//msg2 = "hello"

Answer 4

Try this method:

string message3 = char.ConvertFromUtf32(message2);

• 104 is the value of "h" not "hello".

Answer 5

There is no integer representation of a string, only of a char. Therefore, as stated by others, 104 is not the value of "hello" (a string) but of 'h' (a char) (see the ASCII chart here ).

I can't entirely think of why you'd want to convert a string to an int-array and then back into a string, but the way to do it would be to run through the string and get the int-value of each character and then reconvert the int-values into char-values and concatenate each of them. So something like

string str = "hello"
List<int> N = new List<int>();
//this creates the list of int-values
for(int i=0;i<str.Count;i++)
  N.Add((int)str[i]);
//and this joins it all back into a string
string newString = "";
for(int i=0;i<str.Count;i++)
  newString += (char)N[i];