Color.ToArgb Metodo
Definizione
Importante
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Ottiene il valore ARGB a 32 bit di questa struttura Color.
public:
int ToArgb();public int ToArgb ();member this.ToArgb : unit -> intPublic Function ToArgb () As IntegerRestituisce
Valore ARGB a 32 bit di questo Color.
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 punto elenco. Vengono visualizzati anche il nome del KnownColor e i relativi valori del componente.
In questo esempio vengono visualizzati determinati colori noti, i nomi dei colori e i relativi quattro valori dei componenti. Il metodo ToArgb viene usato come passaggio preliminare per visualizzare i valori del componente.
void ToArgbToStringExample1( 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 ToArgbToStringExample1(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 ToArgbToStringExample1(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
L'ordinamento dei byte del valore ARGB a 32 bit è AARRGGBB. Il byte più significativo (MSB), rappresentato da AA, è il valore del componente alfa. Il secondo, terzo e quarto byte, rappresentato rispettivamente da RR, GG e BB, sono i componenti di colore rosso, verde e blu, rispettivamente
