Console.Read Método

Definición

Lee el siguiente carácter del flujo de entrada estándar.Reads the next character from the standard input stream.

public:
 static int Read();
[System.Runtime.Versioning.UnsupportedOSPlatform("browser")]
public static int Read ();
public static int Read ();
[<System.Runtime.Versioning.UnsupportedOSPlatform("browser")>]
static member Read : unit -> int
static member Read : unit -> int
Public Shared Function Read () As Integer

Devoluciones

Int32

El carácter siguiente del flujo de entrada o menos uno (-1) si no hay actualmente más caracteres que leer.The next character from the input stream, or negative one (-1) if there are currently no more characters to be read.

Atributos

Excepciones

Error de E/S.An I/O error occurred.

Ejemplos

En el siguiente ejemplo se muestra el Read método.The following example demonstrates the Read method.

// This example demonstrates the Console.Read() method.
using namespace System;
int main()
{
   String^ m1 = "\nType a string of text then press Enter. "
   "Type '+' anywhere in the text to quit:\n";
   String^ m2 = "Character '{0}' is hexadecimal 0x{1:x4}.";
   String^ m3 = "Character     is hexadecimal 0x{0:x4}.";
   Char ch;
   int x;
   
   //
   Console::WriteLine( m1 );
   do
   {
      x = Console::Read();
      try
      {
         ch = Convert::ToChar( x );
         if ( Char::IsWhiteSpace( ch ) )
         {
            Console::WriteLine( m3, x );
            if ( ch == 0x0a )
                        Console::WriteLine( m1 );
         }
         else
                  Console::WriteLine( m2, ch, x );
      }
      catch ( OverflowException^ e ) 
      {
         Console::WriteLine( "{0} Value read = {1}.", e->Message, x );
         ch = Char::MinValue;
         Console::WriteLine( m1 );
      }

   }
   while ( ch != '+' );
}

/*
This example produces the following results:

Type a string of text then press Enter. Type '+' anywhere in the text to quit:

The quick brown fox.
Character 'T' is hexadecimal 0x0054.
Character 'h' is hexadecimal 0x0068.
Character 'e' is hexadecimal 0x0065.
Character     is hexadecimal 0x0020.
Character 'q' is hexadecimal 0x0071.
Character 'u' is hexadecimal 0x0075.
Character 'i' is hexadecimal 0x0069.
Character 'c' is hexadecimal 0x0063.
Character 'k' is hexadecimal 0x006b.
Character     is hexadecimal 0x0020.
Character 'b' is hexadecimal 0x0062.
Character 'r' is hexadecimal 0x0072.
Character 'o' is hexadecimal 0x006f.
Character 'w' is hexadecimal 0x0077.
Character 'n' is hexadecimal 0x006e.
Character     is hexadecimal 0x0020.
Character 'f' is hexadecimal 0x0066.
Character 'o' is hexadecimal 0x006f.
Character 'x' is hexadecimal 0x0078.
Character '.' is hexadecimal 0x002e.
Character     is hexadecimal 0x000d.
Character     is hexadecimal 0x000a.

Type a string of text then press Enter. Type '+' anywhere in the text to quit:

^Z
Value was either too large or too small for a character. Value read = -1.

Type a string of text then press Enter. Type '+' anywhere in the text to quit:

+
Character '+' is hexadecimal 0x002b.

*/
// This example demonstrates the Console.Read() method.
using System;

class Sample
{
    public static void Main()
    {
    string m1 = "\nType a string of text then press Enter. " +
                "Type '+' anywhere in the text to quit:\n";
    string m2 = "Character '{0}' is hexadecimal 0x{1:x4}.";
    string m3 = "Character     is hexadecimal 0x{0:x4}.";
    char ch;
    int x;
//
    Console.WriteLine(m1);
    do
        {
        x = Console.Read();
        try
            {
            ch = Convert.ToChar(x);
            if (Char.IsWhiteSpace(ch))
               {
               Console.WriteLine(m3, x);
               if (ch == 0x0a)
                   Console.WriteLine(m1);
               }
            else
                {
                    Console.WriteLine(m2, ch, x);
                }
            }
        catch (OverflowException e)
            {
            Console.WriteLine("{0} Value read = {1}.", e.Message, x);
            ch = Char.MinValue;
            Console.WriteLine(m1);
            }
        } while (ch != '+');
    }
}
/*
This example produces the following results:

Type a string of text then press Enter. Type '+' anywhere in the text to quit:

The quick brown fox.
Character 'T' is hexadecimal 0x0054.
Character 'h' is hexadecimal 0x0068.
Character 'e' is hexadecimal 0x0065.
Character     is hexadecimal 0x0020.
Character 'q' is hexadecimal 0x0071.
Character 'u' is hexadecimal 0x0075.
Character 'i' is hexadecimal 0x0069.
Character 'c' is hexadecimal 0x0063.
Character 'k' is hexadecimal 0x006b.
Character     is hexadecimal 0x0020.
Character 'b' is hexadecimal 0x0062.
Character 'r' is hexadecimal 0x0072.
Character 'o' is hexadecimal 0x006f.
Character 'w' is hexadecimal 0x0077.
Character 'n' is hexadecimal 0x006e.
Character     is hexadecimal 0x0020.
Character 'f' is hexadecimal 0x0066.
Character 'o' is hexadecimal 0x006f.
Character 'x' is hexadecimal 0x0078.
Character '.' is hexadecimal 0x002e.
Character     is hexadecimal 0x000d.
Character     is hexadecimal 0x000a.

Type a string of text then press Enter. Type '+' anywhere in the text to quit:

^Z
Value was either too large or too small for a character. Value read = -1.

Type a string of text then press Enter. Type '+' anywhere in the text to quit:

+
Character '+' is hexadecimal 0x002b.

*/
' This example demonstrates the Console.Read() method.
Class Sample
   Public Shared Sub Main()
      Dim m1 As String = _
                vbCrLf & _
                "Type a string of text then press Enter. " & _
                "Type '+' anywhere in the text to quit:" & _
                vbCrLf
      Dim m2 As String = "Character '{0}' is hexadecimal 0x{1:x4}."
      Dim m3 As String = "Character     is hexadecimal 0x{0:x4}."
      Dim ch As Char
      Dim x As Integer
      '
      Console.WriteLine(m1)
      Do
         x = Console.Read()
         Try
            ch = Convert.ToChar(x)
            If Char.IsWhiteSpace(ch) Then
               Console.WriteLine(m3, x)
               If ch = vbLf Then
                  Console.WriteLine(m1)
               End If
            Else
               Console.WriteLine(m2, ch, x)
            End If
         Catch e As OverflowException
            Console.WriteLine("{0} Value read = {1}.", e.Message, x)
            ch = Char.MinValue
            Console.WriteLine(m1)
         End Try
      Loop While ch <> "+"c
   End Sub
End Class
'
'This example produces the following results:
'
'Type a string of text then press Enter. Type '+' anywhere in the text to quit:
'
'The quick brown fox.
'Character 'T' is hexadecimal 0x0054.
'Character 'h' is hexadecimal 0x0068.
'Character 'e' is hexadecimal 0x0065.
'Character     is hexadecimal 0x0020.
'Character 'q' is hexadecimal 0x0071.
'Character 'u' is hexadecimal 0x0075.
'Character 'i' is hexadecimal 0x0069.
'Character 'c' is hexadecimal 0x0063.
'Character 'k' is hexadecimal 0x006b.
'Character     is hexadecimal 0x0020.
'Character 'b' is hexadecimal 0x0062.
'Character 'r' is hexadecimal 0x0072.
'Character 'o' is hexadecimal 0x006f.
'Character 'w' is hexadecimal 0x0077.
'Character 'n' is hexadecimal 0x006e.
'Character     is hexadecimal 0x0020.
'Character 'f' is hexadecimal 0x0066.
'Character 'o' is hexadecimal 0x006f.
'Character 'x' is hexadecimal 0x0078.
'Character '.' is hexadecimal 0x002e.
'Character     is hexadecimal 0x000d.
'Character     is hexadecimal 0x000a.
'
'Type a string of text then press Enter. Type '+' anywhere in the text to quit:
'
'^Z
'Value was either too large or too small for a character. Value read = -1.
'
'Type a string of text then press Enter. Type '+' anywhere in the text to quit:
'
'+
'Character '+' is hexadecimal 0x002b.
'

Comentarios

El Read método bloquea su devolución mientras escribe caracteres de entrada; finaliza cuando presiona la Enter tecla.The Read method blocks its return while you type input characters; it terminates when you press the Enter key. Al presionar entrar, se anexa una secuencia de finalización de línea dependiente de la plataforma a la entrada (por ejemplo, Windows anexa una secuencia de retorno de carro y avance de línea).Pressing Enter appends a platform-dependent line termination sequence to your input (for example, Windows appends a carriage return-linefeed sequence). Las llamadas subsiguientes al Read método recuperan la entrada de un carácter cada vez.Subsequent calls to the Read method retrieve your input one character at a time. Una vez recuperado el carácter final, vuelve Read a bloquear su retorno y el ciclo se repite.After the final character is retrieved, Read blocks its return again and the cycle repeats.

Importante

El ReadLine método, o la KeyAvailable propiedad y el ReadKey método son preferibles a utilizar el Read método.The ReadLine method, or the KeyAvailable property and ReadKey method are preferable to using the Read method.

Tenga en cuenta que el método no devuelve-1 a menos que realice una de las acciones siguientes:Note that the method does not return -1 unless you perform one of the following actions:

  • Presione simultáneamente la Control tecla modificadora y la Z tecla de consola (Ctrl + Z), que indica la condición de final de archivo.Simultaneously press the Control modifier key and Z console key (Ctrl+Z), which signals the end-of-file condition.

  • Presione una tecla equivalente que señale la condición de final de archivo, como la tecla de función F6 en Windows.Press an equivalent key that signals the end-of-file condition, such as the F6 function key in Windows.

  • Redirija el flujo de entrada a un origen, como un archivo de texto, que tiene un carácter de fin de archivo real.Redirect the input stream to a source, such as a text file, that has an actual end-of-file character.

Se aplica a

Consulte también