Color.GetBrightness 方法
定义
public:
float GetBrightness();
public float GetBrightness ();
member this.GetBrightness : unit -> single
Public Function GetBrightness () As Single
返回
此 Color 的亮度。The lightness of this Color. 亮度范围为 0.0 到 1.0,其中 0.0 表示黑色,1.0 表示白色。The lightness ranges from 0.0 through 1.0, where 0.0 represents black and 1.0 represents white.
示例
下面的代码示例旨在与 Windows 窗体一起使用,并且它需要作为 PaintEventArgs e Paint 事件处理程序的参数。The following code example is designed for use with Windows Forms, and it requires PaintEventArgs e, which is a parameter of the Paint event handler. 此代码执行以下操作:The code performs the following actions:
创建结构的实例,该实例 Color
redShade用于比较。Creates an instance of a Color structure,redShade, to be used for comparisons.循环访问 KnownColor 枚举元素,查找与亮度相同的所有已知颜色
redShade。Iterates through the KnownColor enumeration elements to find all known colors that have the same lightness asredShade. 如果找到15个匹配项或循环计数器的值大于最后一个元素,则将终止迭代 KnownColor 。The iterations are terminated when 15 matches are found or the value of the loop counter is greater than the last KnownColor element.在每次迭代过程中, KnownColor 如果元素与数组中的条件匹配,则保存元素。During each iteration, saves the KnownColor element - if it matches the criteria - in an array.
使用画笔绘制矩形。Uses a brush to paint rectangles.
第一个矩形绘制由表示的颜色 redShade 。The first rectangle is painted the color represented by redShade. 其中的每个矩形都绘制一个 KnownColor 与亮度匹配的 redShade 。Each of the other rectangles is painted a KnownColor that matches the lightness of the redShade.
void KnownColorBrightnessExample2( 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 KnownColorBrightnessExample2(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 KnownColorBrightnessExample2(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