This method is used to convert the specified string, which encodes binary data as base-64 digits, to an equivalent 8-bit unsigned integer array.
Syntax:
public static byte[] FromBase64String (string s);
Here, s is the string to convert.
Return Value: This method returns an array of 8-bit unsigned integers that is equivalent to s.
Exceptions
- ArgumentNullException: If the s is null.
- FormatException: If the length of s, ignoring white-space characters, is not zero or a multiple of 4. OR the format of s is invalid. s contains a non-base-64 character, more than two padding characters, or a non-white space character among the padding characters.
Below programs illustrate the use of Convert.FromBase64String(String) Method:
Example 1:
// C# program to demonstrate the // Convert.FromBase64String(String) Method using System;
class GFG {
// Main Method
public static void Main()
{
try {
// defining and initializing
// byte1 and byte2
byte [] byte1 = {2, 4, 6, 8, 10,
12, 14, 16, 18, 20};
byte [] byte2 = {10, 20, 30,
40, 50};
// calling get() Method
get (byte1, "byte1" );
Console.WriteLine( "" );
get (byte2, "byte2" );
}
catch (ArgumentNullException e) {
Console.Write( "Exception Thrown: " );
Console.Write( "{0}" , e.GetType(), e.Message);
}
catch (FormatException e) {
Console.Write( "Exception Thrown: " );
Console.Write( "{0}" , e.GetType(),
e.Message);
}
}
// Defining get() method
public static void get ( byte [] bytes, string str)
{
Console.WriteLine( "For {0}" , str);
// converting byte to base 64 string
string s = Convert.ToBase64String(bytes);
Console.WriteLine( "The base 64 string: '{0}'" , s);
Console.WriteLine( "The base 64 string: '{0}'" , s);
// converting base 64 string to byte array
byte [] val = Convert.FromBase64String(s);
Console.WriteLine( "Converted byte value: {0}" ,
BitConverter.ToString(val));
}
} |
Output:
For byte1 The base 64 string: 'AgQGCAoMDhASFA==' The base 64 string: 'AgQGCAoMDhASFA==' Converted byte value: 02-04-06-08-0A-0C-0E-10-12-14 For byte2 The base 64 string: 'ChQeKDI=' The base 64 string: 'ChQeKDI=' Converted byte value: 0A-14-1E-28-32
Example 2: For ArgumentNullException
// C# program to demonstrate the // Convert.FromBase64String(String) Method using System;
class GFG {
// Main Method
public static void Main()
{
try {
// defining and initializing
// byte1 and byte2
byte [] byte1 = {2, 4, 6, 8, 10, 12,
14, 16, 18, 20};
// calling get() Method
get (byte1, "byte1" );
Console.WriteLine( "" );
// converting base 64 string to byte array
Console.WriteLine( "s is null" );
byte [] val = Convert.FromBase64String( null );
Console.WriteLine( "Converted byte value: {0}" ,
BitConverter.ToString(val));
}
catch (ArgumentNullException e) {
Console.Write( "Exception Thrown: " );
Console.Write( "{0}" , e.GetType(), e.Message);
}
catch (FormatException e) {
Console.Write( "Exception Thrown: " );
Console.Write( "{0}" , e.GetType(), e.Message);
}
}
// Defining get() method
public static void get ( byte [] bytes, string str)
{
Console.WriteLine( "For {0}" , str);
// converting byte to base 64 string
string s = Convert.ToBase64String(bytes);
Console.WriteLine( "The base 64 string: '{0}'" , s);
// converting base 64 string to byte array
byte [] val = Convert.FromBase64String(s);
Console.WriteLine( "Converted byte value: {0}" ,
BitConverter.ToString(val));
}
} |
Output:
For byte1 The base 64 string: 'AgQGCAoMDhASFA==' Converted byte value: 02-04-06-08-0A-0C-0E-10-12-14 s is null Exception Thrown: System.ArgumentNullException
Example 3: For FormatException
// C# program to demonstrate the // Convert.FromBase64String(String) Method using System;
class GFG {
// Main Method
public static void Main()
{
try {
// defining and initializing
// byte1 and byte2
byte [] byte1 = {2, 4, 6, 8, 10,
12, 14, 16, 18, 20};
// calling get() Method
get (byte1, "byte1" );
Console.WriteLine( "" );
// converting base 64
// string to byte array
Console.WriteLine( "s contains a non-base-64 character" );
byte [] val = Convert.FromBase64String( "sun" );
Console.WriteLine( "Converted byte value: {0}" ,
BitConverter.ToString(val));
}
catch (ArgumentNullException e) {
Console.Write( "Exception Thrown: " );
Console.Write( "{0}" , e.GetType(), e.Message);
}
catch (FormatException e) {
Console.Write( "Exception Thrown: " );
Console.Write( "{0}" , e.GetType(), e.Message);
}
}
// Defining get() method
public static void get ( byte [] bytes, string str)
{
Console.WriteLine( "For {0}" , str);
// converting byte to base 64 string
string s = Convert.ToBase64String(bytes);
Console.WriteLine( "The base 64 string: '{0}'" , s);
// converting base 64 string to byte array
byte [] val = Convert.FromBase64String(s);
Console.WriteLine( "Converted byte value: {0}" ,
BitConverter.ToString(val));
}
} |
Output:
For byte1 The base 64 string: 'AgQGCAoMDhASFA==' Converted byte value: 02-04-06-08-0A-0C-0E-10-12-14 s contains a non-base-64 character Exception Thrown: System.FormatException
Reference: