用IronRuby创建WPF应用程序
2010-10-09 08:15:31 来源:WEB开发网我曾在早期的博文中介绍过IronRuby。在文章中,我扩展了IronRuby的基础知识,来解释需要在Rail应用程序所做的额外工作,好让大家继续深入.NET所实现Ruby语言,但这方面的内容并不够。所以现在我想深入地谈谈IronRuby与项目的兼容性,以便开发全新的应用程序来说明IronRuby和.NET之间的互操作性。实际上,我们会使用WPF(Windows Presentation Foundation),它是.NET Framework的组件,我们可以用它创建富媒体和图形界面。
WPF基础
再次申明,WPF是.NET Framework组件之一,负责呈现富用户界面和其他媒体。它不是.NET Framework中唯一可完成该功能的函数库集,Window Form也可以完成类似工作,在我们需要创建炫目效果的时候,WPF会显得十分有用。无论是演示文档、视频、数据录入表格、某些类型的数据可视化(这是我最希望做的,尤其用IronRuby完成,后面的故事更精彩)抑或用动画把以上的都串联起来,你很可能会发现在给Windows开发这些应用程序的时候 WPF可以满足你的需求。
举例说明。某一天午饭时间,我创建了基于WPF的类似于时钟的应用程序——我喜欢参考WPF的“Hello,Wold”应用程序——于是决定使用IronRuby。
注:学习本示例的过程中,需要参考WPF文档。
示例程序
require 'WindowsBase'
require 'PresentationFramework'
require 'PresentationCore'
require 'System.Core, Version=3.5.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089'
class Clock
CLOCK_WIDTH = 150
CLOCK_HEIGHT = 150
LABEL_HEIGHT = CLOCK_HEIGHT / 7
LABEL_WIDTH = CLOCK_WIDTH / 7
RADIUS = CLOCK_WIDTH / 2
RADS = Math::PI / 180
MIN_LOCATIONS = {}
HOUR_LOCATIONS = {}
def run!
plot_locations
# build our window
@window = System::Windows::Window.new
@window.background = System::Windows::Media::Brushes.LightGray
@window.width = CLOCK_WIDTH * 2
@window.height = CLOCK_HEIGHT * 2
@window.resize_mode = System::Windows::ResizeMode.NoResize
@canvas = System::Windows::Controls::Canvas.new
@canvas.width = CLOCK_WIDTH
@canvas.height = CLOCK_HEIGHT
# create shapes to represent clock hands
@minute_hand = System::Windows::Shapes::Line.new
@minute_hand.stroke = System::Windows::Media::Brushes.Black
@minute_hand.stroke_thickness = 1
@minute_hand.x1 = CLOCK_WIDTH / 2
@minute_hand.y1 = CLOCK_HEIGHT / 2
@hour_hand = System::Windows::Shapes::Line.new
@hour_hand.stroke = System::Windows::Media::Brushes.Black
@hour_hand.stroke_thickness = 3
@hour_hand.x1 = CLOCK_WIDTH / 2
@hour_hand.y1 = CLOCK_HEIGHT / 2
# .. and stick them to our canvas
@canvas.children.add(@minute_hand)
@canvas.children.add(@hour_hand)
plot_face # draw a clock face
plot_labels # draw clock numbers
plot_hands # draw minute / hour hands
@window.content = @canvas
app = System::Windows::Application.new
app.run(@window)
# the Application object handles the lifecycle of our app
# including the execution loop
end
# determine 2 sets of equidistant points around the circumference of a circle
# of CLOCK_WIDTH and CLOCK_HEIGHT dimensions.
def plot_locations
for i in (0..60) # 60 minutes, and 12 hours
a = i * 6
x = (RADIUS * Math.sin(a * RADS)).to_i + (CLOCK_WIDTH / 2)
y = (CLOCK_HEIGHT / 2) - (RADIUS * Math.cos(a * RADS)).to_i
coords = [x, y]
HOUR_LOCATIONS[i / 5] = coords if i % 5 == 0 # is this also an 'hour' location (ie. every 5 minutes)?
MIN_LOCATIONS[i] = coords
end
end
# draws a circle to represent the clock's face
def plot_face
extra_x = (CLOCK_WIDTH * 0.15) # pad our circle a little
extra_y = (CLOCK_HEIGHT * 0.15)
face = System::Windows::Shapes::Ellipse.new
face.fill = System::Windows::Media::Brushes.White
face.width = CLOCK_WIDTH + extra_x
face.height = CLOCK_HEIGHT + extra_y
face.margin = System::Windows::Thickness.new(0 - (extra_x/2), 0 - (extra_y/2), 0, 0)
face.stroke = System::Windows::Media::Brushes.Gray # give it a slight border
face.stroke_thickness = 1
System::Windows::Controls::Canvas.set_z_index(face, -1) # send our circle to the back
@canvas.children.add(face) # add the clock face to our canvas
end
# at each point along the hour locations, put a number
def plot_labels
HOUR_LOCATIONS.each_pair do |p, coords|
unless p == 0
lbl = System::Windows::Controls::Label.new
lbl.horizontal_content_alignment = System::Windows::HorizontalAlignment.Center
lbl.width = LABEL_WIDTH
lbl.height = LABEL_HEIGHT
lbl.content = p.to_s
lbl.margin = System::Windows::Thickness.new(coords[0] - (LABEL_WIDTH / 2), coords[1] - (LABEL_HEIGHT / 2), 0, 0)
lbl.padding = System::Windows::Thickness.new(0, 0, 0, 0)
@canvas.children.add(lbl)
end
end
end
def plot_hands
time = Time.now
hours = time.hour
minutes = time.min
if !@minutes || minutes != @minutes
@hours = hours >= 12 ? hours - 12 : hours
@minutes = minutes == 0 ? 60 : minutes
# Dispatcher.BeginInvoke() is asynchronous, though it probably doesn't matter too much here
@minute_hand.dispatcher.begin_invoke(System::Windows::Threading::DispatcherPriority.Render, System::Action.new {
@minute_hand.x2 = MIN_LOCATIONS[@minutes][0]
@minute_hand.y2 = MIN_LOCATIONS[@minutes][1]
@hour_hand.x2 = HOUR_LOCATIONS[@hours][0]
@hour_hand.y2 = HOUR_LOCATIONS[@hours][1]
})
end
end
end
clock = Clock.new
timer = System::Timers::Timer.new
timer.interval = 1000
timer.elapsed { clock.plot_hands }
timer.enabled = true
clock.run!
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