ruby tk中的grid布局

grid虽然简单，但是本人想通过grid，说些其它的问题。tk的资料本来就比较少，而ruby tk的资料当然就更少了，所以需要一点一点的去尝试。

先帖上一个图：

接下来帖上代码：

require 'tk' 

root = TkRoot.new {
   title "布局测试"
   minsize(200,200)
}

frame = TkFrame.new do
  relief 'sunken'
  borderwidth 3
  background "red"
  padx 15
  pady 20
  pack('side' => 'left')
end

TkButton.new(frame) do  
  text "按钮1"
  background "#ccc" 
  grid :column=>1,:row=>1,:ipadx=>10,:ipady=>10
end 

TkButton.new(frame) do  
  text "按钮2" 
  background "#ccc"
  grid :column=>2,:row=>2
end 

TkButton.new(frame) do  
  text "删除整个frame" 
  background "#ccc"
  command{
  	frame.unpack
  	TkLabel.new do
  		text "删除整个frame成功！"
  		pack
  	end
  }
  grid :column=>0,:row=>0,:rowspan=>5,:sticky=>"nsew"
end 

TkButton.new(frame) do  
  text "按钮4" 
  background "#ccc"
  grid :column=>2,:row=>1
end 

button5 = TkButton.new(frame) do  
  text "按钮5" 
  background "#ccc"
  grid :column=>1,:row=>2
end

TkButton.new(frame) do  
  text "删除按钮5" 
  background "#ccc"
  command{button5.grid_forget}
  grid :column=>1,:row=>4,:columnspan=>3,:sticky=>"nsew"
end 

Tk.mainloop

针对这段代码，讲几点：

1.使用grid布局后，就不要再使用pack方式了。

2.跨行、跨列使用columnspan、rowspan这两个属性，但是如果只使用这两个属性的话，按钮只会占据中间的一个格式，不会自动填满。如果要自动占满整行或整列，需要使用sticky属性。关于sticky这个属性，英文的描述是这样的：

The value associated with -sticky is a string containing the compass points to which the widget should "stick." If the widget should always "stick" to the top of the cell, you would use -sticky => "n". To force the widget to fill the cell completely, use -sticky => "nsew". To make the widget as tall as the cell but only as wide as it needs to be, use -sticky => "ns". The string value can contain commas and whitespace, but they will be ignored. These two statements are equivalent:

3.关于ipadx、ipady，其实前一篇博客已经说了，再引用一下吧:

-ipadx => amount $widget becomes larger in x direction by 2 ✕ amount.

-ipady => amount $widget becomes larger in y direction by 2 ✕ amount.

-padx => amount Buffer space equal to amount is placed to left and right of widget.

-pady => amount Buffer space equal to amount is placed on top and bottom of widget.

4.其实本人最想说的，是关于怎么来删除按钮或者整个frame，在上面的图中，就实现了这两个功能。删除按钮，使用的是grid_forget方法，而删除frame，使用的是unpack。这两个功能是很重要的，在JAVA 的SWING中，一般通过设置显示或隐藏的方法（专门有设置一个组件显示或隐藏的方法），而在TK中，翻遍了所有资料，就是没找到，最后在翻看ruby源代码时，看见这个方法有点像，试了下果然行，真是不容易！