Color.FromKnownColor(KnownColor) Metoda

Definice

Obor názvů:

System.Drawing

Sestavení:

System.Drawing.Primitives.dll

Zdroj:

Color.cs

Vytvoří Color strukturu ze zadané předdefinované barvy.

public:
 static System::Drawing::Color FromKnownColor(System::Drawing::KnownColor color);

public static System.Drawing.Color FromKnownColor (System.Drawing.KnownColor color);

static member FromKnownColor : System.Drawing.KnownColor -> System.Drawing.Color

Public Shared Function FromKnownColor (color As KnownColor) As Color

Parametry

color

KnownColor

Prvek KnownColor výčtu.

Návraty

Color

Color, kterou tato metoda vytvoří.

Příklady

Následující příklad kódu je určený pro použití s Windows Forms a vyžaduje PaintEventArgse, což je parametr obslužné rutiny události Paint. Kód provede následující akce:

• Vytvoří instanci struktury Color, redShade, která se použije pro porovnání.

• Iteruje přes KnownColor výčtové prvky najít všechny známé barvy, které mají stejnou světlost jako redShade. Iterace jsou ukončeny při nalezení 15 shod nebo hodnota čítače smyčky je větší než poslední KnownColor prvek.

• Během každé iterace uloží prvek KnownColor – pokud odpovídá kritériím – v poli.

• Používá štětec k malování obdélníků.

První obdélník je malován barvu reprezentovanou redShade. Každý z ostatních obdélníků je malován KnownColor, který odpovídá světlu redShade.

void KnownColorBrightnessExample1( PaintEventArgs^ e )
{
   Graphics^ g = e->Graphics;

   // Color structures. One is a variable used for temporary storage. The other
   // is a constant used for comparisons.
   Color someColor = Color::FromArgb( 0 );
   Color redShade = Color::FromArgb( 255, 200, 0, 100 );

   // Array to store KnownColor values that match the brightness of the
   // redShade color.
   array<KnownColor>^colorMatches = gcnew array<KnownColor>(15);

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

   // Iterate through the KnownColor enums until 15 matches are found.
   for ( KnownColor enumValue = (KnownColor)0; enumValue <= KnownColor::YellowGreen && count < 15; enumValue = enumValue + (KnownColor)1 )
   {
      someColor = Color::FromKnownColor( enumValue );
      if ( someColor.GetBrightness() == redShade.GetBrightness() )
               colorMatches[ count++ ] = enumValue;
   }

   // Display the redShade color and its argb value.
   SolidBrush^ myBrush1 = gcnew SolidBrush( redShade );
   System::Drawing::Font^ myFont = gcnew System::Drawing::Font( "Arial",12 );
   int x = 20;
   int y = 20;
   someColor = redShade;
   g->FillRectangle( myBrush1, x, y, 100, 30 );
   g->DrawString( someColor.ToString(), myFont, Brushes::Black, (float)x + 120, (float)y );
   
   // 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.
   for ( int i = 0; i < count; i++ )
   {
      y += 40;
      someColor = Color::FromKnownColor( colorMatches[ i ] );
      myBrush1->Color = someColor;
      g->FillRectangle( myBrush1, x, y, 100, 30 );
      g->DrawString( someColor.ToString(), myFont, Brushes::Black, (float)x + 120, (float)y );
   }
}

public void KnownColorBrightnessExample1(PaintEventArgs e)
{
    Graphics     g = e.Graphics;
             
    // Color structures. One is a variable used for temporary storage. The other
    // is a constant used for comparisons.
    Color   someColor = Color.FromArgb(0);
    Color   redShade = Color.FromArgb(255, 200, 0, 100);
             
    // Array to store KnownColor values that match the brightness of the
    // redShade color.
    KnownColor[]  colorMatches = new KnownColor[15];
     
    // Number of matches found.
    int  count = 0;   
          
    // Iterate through the KnownColor enums until 15 matches are found.
    for (KnownColor enumValue = 0;
        enumValue <= KnownColor.YellowGreen && count < 15; enumValue++)
    {
        someColor = Color.FromKnownColor(enumValue);
        if (someColor.GetBrightness() == redShade.GetBrightness())
            colorMatches[count++] = enumValue;
    }
             
    // Display the redShade color and its argb value.
    SolidBrush  myBrush1 = new SolidBrush(redShade);
    Font        myFont = new Font("Arial", 12);
    int         x = 20;
    int         y = 20;
    someColor = redShade;
    g.FillRectangle(myBrush1, x, y, 100, 30);
    g.DrawString(someColor.ToString(), myFont, Brushes.Black, x + 120, y);
             
    // 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.
    for (int i = 0; i < count; i++)
    {
        y += 40;
        someColor = Color.FromKnownColor(colorMatches[i]);
        myBrush1.Color = someColor;
        g.FillRectangle(myBrush1, x, y, 100, 30);
        g.DrawString(someColor.ToString(), myFont, Brushes.Black, x + 120, y);
    }
}

Public Sub KnownColorBrightnessExample1(ByVal e As PaintEventArgs)
    Dim g As Graphics = e.Graphics

    ' Color structures. One is used for temporary storage. The other
    ' is a constant used for comparisons.
    Dim someColor As Color = Color.FromArgb(0)
    Dim redShade As Color = Color.FromArgb(255, 200, 0, 100)

    ' Array to store KnownColor values that match the brightness of the
    ' redShade color.
    Dim colorMatches(15) As KnownColor

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

    ' iterate through the KnownColor enums until 15 matches are found.
    Dim enumValue As KnownColor
    For enumValue = 0 To KnownColor.YellowGreen
        someColor = Color.FromKnownColor(enumValue)
        If (someColor.GetBrightness()) = (redShade.GetBrightness()) Then
            colorMatches(count) = enumValue
            count += 1
            If count > 15 Then
                Exit For
            End If
        End If
    Next enumValue

    ' Display the redShade color and its argb value.
    Dim myBrush1 As New SolidBrush(redShade)
    Dim myFont As New Font("Arial", 12)
    Dim x As Integer = 20
    Dim y As Integer = 20
    someColor = redShade
    g.FillRectangle(myBrush1, x, y, 100, 30)
    g.DrawString(someColor.ToString(), myFont, Brushes.Black, _
    x + 120, y)

    ' Iterate through the matches that were found and display each
    ' color that corresponds with the enum value in the array.
    ' Display the name of the KnownColor.
    Dim i As Integer
    For i = 0 To count - 1
        y += 40
        someColor = Color.FromKnownColor(colorMatches(i))
        myBrush1.Color = someColor
        g.FillRectangle(myBrush1, x, y, 100, 30)
        g.DrawString(someColor.ToString(), myFont, Brushes.Black, _
        x + 120, y)
    Next i
End Sub

Poznámky

Předdefinovaná barva se také nazývá známá barva a je reprezentována prvkem KnownColor výčtu.