String.Contains String.Contains String.Contains String.Contains Method

Definición

Sobrecargas

Contains(Char) Contains(Char) Contains(Char) Contains(Char)
Contains(String) Contains(String) Contains(String) Contains(String)

Devuelve un valor que indica si una subcadena especificada aparece dentro de esta cadena.Returns a value indicating whether a specified substring occurs within this string.

Contains(Char, StringComparison) Contains(Char, StringComparison) Contains(Char, StringComparison) Contains(Char, StringComparison)
Contains(String, StringComparison) Contains(String, StringComparison) Contains(String, StringComparison) Contains(String, StringComparison)

Contains(Char) Contains(Char) Contains(Char) Contains(Char)

public:
 bool Contains(char value);
public bool Contains (char value);
member this.Contains : char -> bool
Public Function Contains (value As Char) As Boolean

Parámetros

value
Char Char Char Char

Devoluciones

Contains(String) Contains(String) Contains(String) Contains(String)

Devuelve un valor que indica si una subcadena especificada aparece dentro de esta cadena.Returns a value indicating whether a specified substring occurs within this string.

public:
 bool Contains(System::String ^ value);
public bool Contains (string value);
member this.Contains : string -> bool
Public Function Contains (value As String) As Boolean

Parámetros

value
String String String String

Cadena que se va a buscar.The string to seek.

Devoluciones

Es true si el parámetro value aparece en esta cadena o si value es la cadena vacía (""); en caso contrario, es false.true if the value parameter occurs within this string, or if value is the empty string (""); otherwise, false.

Excepciones

Ejemplos

El ejemplo siguiente determina si la cadena "fox" es una subcadena de una cita conocida.The following example determines whether the string "fox" is a substring of a familiar quotation. Si "zorro" se encuentra en la cadena, también muestra su posición inicial.If "fox" is found in the string, it also displays its starting position.

using namespace System;

int main()
{
   String^ s1 = "The quick brown fox jumps over the lazy dog";
   String^ s2 = "fox";
   bool b = s1->Contains( s2 );
   Console::WriteLine( "Is the string, s2, in the string, s1?: {0}", b );
   if (b) {
      int index = s1->IndexOf(s2);
      if (index >= 0)
         Console::WriteLine("'{0} begins at character position {1}",
                            s2, index + 1);
   }
}
// This example displays the following output:
//    'fox' is in the string 'The quick brown fox jumps over the lazy dog': True
//    'fox begins at character position 17
using System;

class Example
{
    public static void Main() 
    {
       string s1 = "The quick brown fox jumps over the lazy dog";
       string s2 = "fox";
       bool b = s1.Contains(s2);
       Console.WriteLine("'{0}' is in the string '{1}': {2}",
                          s2, s1, b);
       if (b) {
          int index = s1.IndexOf(s2);
          if (index >= 0)
             Console.WriteLine("'{0} begins at character position {1}",
                               s2, index + 1);
       }
    }
}
// This example display the following output:
//    'fox' is in the string 'The quick brown fox jumps over the lazy dog': True
//    'fox begins at character position 17
Class Example
   Public Shared Sub Main()
      Dim s1 As String = "The quick brown fox jumps over the lazy dog"
      Dim s2 As String = "fox"
      Dim b As Boolean = s1.Contains(s2)
      Console.WriteLine("'{0}' is in the string '{1}': {2}",
                        s2, s1, b)
      If b Then
          Dim index As Integer = s1.IndexOf(s2)
          If index >= 0 Then
             Console.WriteLine("'{0} begins at character position {1}",
                               s2, index + 1)
          End If
       End If
   End Sub
End Class
'
' This example displays the following output:
'    'fox' is in the string 'The quick brown fox jumps over the lazy dog': True
'    'fox begins at character position 17

Comentarios

Este método realiza una comparación ordinal (distingue mayúsculas de minúsculas y cuenta la referencia cultural).This method performs an ordinal (case-sensitive and culture-insensitive) comparison. La búsqueda comienza en la posición del primer carácter de esta cadena y continúa a través de la última posición de carácter.The search begins at the first character position of this string and continues through the last character position.

Para determinar si una cadena contiene una subcadena especificada mediante el uso de un valor distinto de una comparación ordinal (por ejemplo, la comparación dependiente de la referencia cultural, o comparación ordinal de mayúsculas y minúsculas), puede crear un método personalizado.To determine whether a string contains a specified substring by using something other than ordinal comparison (such as culture-sensitive comparison, or ordinal case-insensitive comparison), you can create a custom method. El ejemplo siguiente muestra uno de estos métodos.The following example illustrates one such approach. Define un String método de extensión que incluye un StringComparison parámetro e indica si una cadena contiene una subcadena al usar el formulario especificado de comparación de cadenas.It defines a String extension method that includes a StringComparison parameter and indicates whether a string contains a substring when using the specified form of string comparison.

using System;

public static class StringExtensions
{
   public static bool Contains(this String str, String substring, 
                               StringComparison comp)
   {                            
      if (substring == null)
         throw new ArgumentNullException("substring", 
                                         "substring cannot be null.");
      else if (! Enum.IsDefined(typeof(StringComparison), comp))
         throw new ArgumentException("comp is not a member of StringComparison",
                                     "comp");

      return str.IndexOf(substring, comp) >= 0;                      
   }
}
Imports System.Runtime.CompilerServices

Module StringExtensions
   <Extension()>
   Public Function Contains(str As String, substring As String, 
                            comp As StringComparison) As Boolean
      If substring Is Nothing Then
         Throw New ArgumentNullException("substring", 
                                         "substring cannot be null.")
      Else If Not [Enum].IsDefined(GetType(StringComparison), comp)
         Throw New ArgumentException("comp is not a member of StringComparison",
                                     "comp")
      End If                               
      Return str.IndexOf(substring, comp) >= 0                      
   End Function
End Module

El ejemplo siguiente, a continuación, llama el Contains método de extensión para determinar si se encuentra una subcadena en una cadena al usar comparación ordinal y comparación de ordinales entre mayúsculas y minúsculas.The following example then calls the Contains extension method to determine whether a substring is found in a string when using ordinal comparison and case-insensitive ordinal comparison.

using System;

public class Example
{
   public static void Main()
   {
      String s = "This is a string.";
      String sub1 = "this";
      Console.WriteLine("Does '{0}' contain '{1}'?", s, sub1);
      StringComparison comp = StringComparison.Ordinal;
      Console.WriteLine("   {0:G}: {1}", comp, s.Contains(sub1, comp));
      
      comp = StringComparison.OrdinalIgnoreCase;
      Console.WriteLine("   {0:G}: {1}", comp, s.Contains(sub1, comp));
   }
}
// The example displays the following output:
//       Does 'This is a string.' contain 'this'?
//          Ordinal: False
//          OrdinalIgnoreCase: True
Public Module Example
   Public Sub Main
      Dim s As String = "This is a string."
      Dim sub1 As String = "this"
      Console.WriteLine("Does '{0}' contain '{1}'?", s, sub1)
      Dim comp As StringComparison = StringComparison.Ordinal
      Console.WriteLine("   {0:G}: {1}", comp, s.Contains(sub1, comp))
      
      comp = StringComparison.OrdinalIgnoreCase
      Console.WriteLine("   {0:G}: {1}", comp, s.Contains(sub1, comp))
   End Sub
End Module
' The example displays the following output:
'       Does 'This is a string.' contain 'this'?
'          Ordinal: False
'          OrdinalIgnoreCase: True

Si está interesado en la posición de la subcadena value en la instancia actual, se puede llamar a la IndexOf puede llamar al método para obtener la posición inicial de su primera aparición, o bien el LastIndexOf colocar el método para obtener el inicio de su última repetición.If you are interested in the position of the substring value in the current instance, you can call the IndexOf method to get the starting position of its first occurrence, or you can call the LastIndexOf method to get the starting position of its last occurrence. El ejemplo incluye una llamada a la IndexOf(String) método si se encuentra una subcadena en una instancia de cadena.The example includes a call to the IndexOf(String) method if a substring is found in a string instance.

Consulte también:

Contains(Char, StringComparison) Contains(Char, StringComparison) Contains(Char, StringComparison) Contains(Char, StringComparison)

public:
 bool Contains(char value, StringComparison comparisonType);
public bool Contains (char value, StringComparison comparisonType);
member this.Contains : char * StringComparison -> bool
Public Function Contains (value As Char, comparisonType As StringComparison) As Boolean

Parámetros

value
Char Char Char Char

Devoluciones

Contains(String, StringComparison) Contains(String, StringComparison) Contains(String, StringComparison) Contains(String, StringComparison)

public:
 bool Contains(System::String ^ value, StringComparison comparisonType);
public bool Contains (string value, StringComparison comparisonType);
member this.Contains : string * StringComparison -> bool
Public Function Contains (value As String, comparisonType As StringComparison) As Boolean

Parámetros

Devoluciones

Se aplica a