Color.ToString Metodo

public:
 override System::String ^ ToString();

public override string ToString ();

override this.ToString : unit -> string

Public Overrides Function ToString () As String

Restituisce

Stringa che corrisponde al nome di questa Color, se il Color viene creato da un colore predefinito utilizzando il metodo FromName(String) o il metodo FromKnownColor(KnownColor); in caso contrario, una stringa costituita dai nomi dei componenti ARGB e dai relativi valori.

Esempio

L'esempio di codice seguente è progettato per l'uso con Windows Form e richiede PaintEventArgse, che è un parametro del gestore eventi Paint. Il codice esegue le azioni seguenti:

• Scorre gli elementi di enumerazione KnownColor per trovare tutti i colori noti che hanno un componente verde diverso da zero e un componente rosso con valore zero e che non sono colori di sistema.

• Durante ogni iterazione, salva l'elemento KnownColor, se corrisponde ai criteri, in una matrice.

• Usa un pennello per disegnare rettangoli. Ogni rettangolo viene disegnato un KnownColor che corrisponde ai criteri indicati nel primo passaggio. Vengono visualizzati anche il nome del KnownColor e i relativi valori del componente.

In questo esempio vengono visualizzati determinati colori noti e vengono usati ToString per visualizzare i nomi dei colori e i relativi quattro valori dei componenti.

void ToArgbToStringExample2( PaintEventArgs^ e )
{
   Graphics^ g = e->Graphics;

   // Color structure used for temporary storage.
   Color someColor = Color::FromArgb( 0 );

   // Array to store KnownColor values that match the criteria.
   array<KnownColor>^colorMatches = gcnew array<KnownColor>(167);

   // Number of matches found.
   int count = 0;

   // Iterate through the KnownColor enums to find all corresponding colors
   // that have a nonzero green component and zero-value red component and
   // that are not system colors.
   for ( KnownColor enumValue = (KnownColor)0; enumValue <= KnownColor::YellowGreen; enumValue = enumValue + (KnownColor)1 )
   {
      someColor = Color::FromKnownColor( enumValue );
      if ( someColor.G != 0 && someColor.R == 0 &&  !someColor.IsSystemColor )
               colorMatches[ count++ ] = enumValue;
   }
   SolidBrush^ myBrush1 = gcnew SolidBrush( someColor );
   System::Drawing::Font^ myFont = gcnew System::Drawing::Font( "Arial",9 );
   int x = 40;
   int y = 40;

   // Iterate through the matches that were found and display each color that
   // corresponds with the enum value in the array. also display the name of
   // the KnownColor and the ARGB components.
   for ( int i = 0; i < count; i++ )
   {
      // Display the color.
      someColor = Color::FromKnownColor( colorMatches[ i ] );
      myBrush1->Color = someColor;
      g->FillRectangle( myBrush1, x, y, 50, 30 );
      
      // Display KnownColor name and the four component values. To display the
      // component values:  Use the ToArgb method to get the 32-bit ARGB value
      // of someColor, which was created from a KnownColor. Then create a
      // Color structure from the 32-bit ARGB value and set someColor equal to
      // this new Color structure. Then use the ToString method to convert it to
      // a string.
      g->DrawString( someColor.ToString(), myFont, Brushes::Black, (float)x + 55, (float)y );
      someColor = Color::FromArgb( someColor.ToArgb() );
      g->DrawString( someColor.ToString(), myFont, Brushes::Black, (float)x + 55, (float)y + 15 );
      y += 40;
   }
}

public void ToArgbToStringExample2(PaintEventArgs e)
{
    Graphics     g = e.Graphics;
             
    // Color structure used for temporary storage.
    Color   someColor = Color.FromArgb(0);
             
    // Array to store KnownColor values that match the criteria.
    KnownColor[]  colorMatches = new KnownColor[167];
    
    // Number of matches found.
    int  count = 0;   
             
    // Iterate through the KnownColor enums to find all corresponding colors
    // that have a nonzero green component and zero-value red component and
    // that are not system colors.
    for (KnownColor enumValue = 0;
        enumValue <= KnownColor.YellowGreen; enumValue++)
    {
        someColor = Color.FromKnownColor(enumValue);
        if (someColor.G != 0 && someColor.R == 0 && !someColor.IsSystemColor)
            colorMatches[count++] = enumValue;
    }
    SolidBrush  myBrush1 = new SolidBrush(someColor);
    Font        myFont = new Font("Arial", 9);
    int         x = 40;
    int         y = 40;
             
    // Iterate through the matches that were found and display each color that
    // corresponds with the enum value in the array. also display the name of
    // the KnownColor and the ARGB components.
    for (int i = 0; i < count; i++)
    {
        // Display the color.
        someColor = Color.FromKnownColor(colorMatches[i]);
        myBrush1.Color = someColor;
        g.FillRectangle(myBrush1, x, y, 50, 30);
             
        // Display KnownColor name and the four component values. To display the
        // component values:  Use the ToArgb method to get the 32-bit ARGB value
        // of someColor, which was created from a KnownColor. Then create a
        // Color structure from the 32-bit ARGB value and set someColor equal to
        // this new Color structure. Then use the ToString method to convert it to
        // a string.
        g.DrawString(someColor.ToString(), myFont, Brushes.Black, x + 55, y);
        someColor = Color.FromArgb(someColor.ToArgb());
        g.DrawString(someColor.ToString(), myFont, Brushes.Black, x + 55, y + 15);
        y += 40;
    }
}

Public Sub ToArgbToStringExample2(ByVal e As PaintEventArgs)
    Dim g As Graphics = e.Graphics

    ' Color structure used for temporary storage.
    Dim someColor As Color = Color.FromArgb(0)

    ' Array to store KnownColor values that match the criteria.
    Dim colorMatches(167) As KnownColor

    ' Number of matches found.
    Dim count As Integer = 0

    ' Iterate through KnownColor enums to find all corresponding colors
    ' that have a non-zero green component and zero-valued red
    ' component and that are not system colors.
    Dim enumValue As KnownColor
    For enumValue = 0 To KnownColor.YellowGreen
        someColor = Color.FromKnownColor(enumValue)
        If someColor.G <> 0 And someColor.R = 0 And _
        Not someColor.IsSystemColor Then
            colorMatches(count) = enumValue
            count += 1
        End If
    Next enumValue
    Dim myBrush1 As New SolidBrush(someColor)
    Dim myFont As New Font("Arial", 9)
    Dim x As Integer = 40
    Dim y As Integer = 40

    ' Iterate through the matches found and display each color that
    ' corresponds with the enum value in the array. Also display the
    ' name of the KnownColor and the ARGB components.
    Dim i As Integer
    For i = 0 To count - 1

        ' Display the color
        someColor = Color.FromKnownColor(colorMatches(i))
        myBrush1.Color = someColor
        g.FillRectangle(myBrush1, x, y, 50, 30)

        ' Display KnownColor name and four component values. To display
        ' component values:  Use the ToArgb method to get the 32-bit
        ' ARGB value of someColor (created from a KnownColor). Create
        ' a Color structure from the 32-bit ARGB value and set someColor
        ' equal to this new Color structure. Then use the ToString method
        ' to convert it to a string.
        g.DrawString(someColor.ToString(), myFont, Brushes.Black, _
        x + 55, y)
        someColor = Color.FromArgb(someColor.ToArgb())
        g.DrawString(someColor.ToString(), myFont, Brushes.Black, _
        x + 55, y + 15)
        y += 40
    Next i
End Sub

Commenti

Un colore predefinito è detto anche colore noto ed è rappresentato da un elemento dell'enumerazione KnownColor. Quando il metodo ToString viene applicato a una struttura Color creata usando il metodo FromArgb, ToString restituisce una stringa costituita dai nomi dei componenti ARGB e dai relativi valori, anche se il valore ARGB corrisponde al valore ARGB di un colore predefinito.

Si applica a