一、创建主菜单m_main。
二、创建主窗口w_main，并将其属性Window Type设置为mdihelp!,将MenuName属性设置为m_main。
三、创建图片窗口w_pic，并在该窗口中放置picture控件，起名为p_1；设置w_pic的属性，把Window Type的属性设置为popup!，选择visible，其它属性全部取消。
四、编写w_pic代码：
⑴、定义实例变量（instance variables）
boolean isfullscreen
integer oldwidth,oldheight
⑵、编写open()事件：
isfullscreen=true
oldwidth=p_1.width
oldheight=p_1.height
⑶、编写resize()事件
if isfullscreen then
p_1.x=0
p_1.y=0
p_1.resize(newwidth,newheight)
else
p_1.resize(oldwidth,odlheight)
integer ax,ay
ax=(newwidth-oldwidth)/2
if ax<0 then ax=0
ay=(newheight-oldheight)/2
if ay<0 then ay=0
p_1.x=ax
p_1.y=ay
end if
⑷、定义function: init(string as_picture,boolean as_isfullscreen) return (none)
参数：
access:public return type:none function name:init
pass by:value argument type:string argument name:as_picture
pass by:value argument type:boolean argument name:as_isfullscreen
代码：
p_1.originalsize=ture
p_1.picturename=as_picture
oldheight=p_1.height
oldwidth=p_1.width
p_1.originalsize=false
this.resize(this.width,this.height)
五、编写w_main代码：
⑴、定义实例变量（instance variables)
w_pic mdipicture
string mdipicturename
boolean mdiisfullscreen
⑵、定义function: setpicture()
参数：
access:public return type:(none) function name:setpicture
pass by:value argument type:string argument name:as_picture
pass by:value argument type:boolean argument name:as_isfullscreent
代码：
mdipicturename=as_picture
mdiisfullscreen=as_isfullscreen
if isvalid(mdipicture) then
mdipicture.init(mdipicturename,mdiisfullscreen)
mdipicture.resize(this.width,this.height)
end if
⑶、编写resize()事件：
if isvalid(mdipicture) = false then
opensheet(mdipicture,this)
mdipicture.init(mdipicturename,mdiisfullscreen)
mdipicture.x=0
mdipicture.y=0
end if
mdipicture.resize(newwidth,newheight)
六、编写application的open()事件
open(w_main)
w_main.setpicture("back.bmp",true)
图1：最小化窗口
图2：最大化窗口
