当前页面位置: » 丰搜网 » 文档中心 » 详细内容
为asp.net控件添加设计时支持(12)
列表 4：blog_dt.vb
'支持设计时特性
imports system.componentmodel
'支持颜色结构
imports system.drawing
'支持 uitypeeditor 类型
imports system.drawing.design
'支持 streamwriter 类型
imports system.io
imports system.web.ui
'支持 controldesigner 类型
' 请注意，必须添加程序集
' system.design 的引用，才能导入此命名空间
imports system.web.ui.design
'支持使用 html 控件
imports system.web.ui.htmlcontrols
'支持使用 web 控件
imports system.web.ui.webcontrols
＜assembly: tagprefix("blogcontrol", "blogcontrol")＞
public enum blogmode
add
display
end enum
＜description("simple blog control.supports display " & _
"of web log / news items from an xml file."), _
designer("blogcontrol.blogdesigner"), _
toolboxdata("＜{0}:blog_dt runat=server＞＜/{0}:blog_dt＞")＞ _
public class blog_dt
inherits panel
implements inamingcontainer
protected blogds as dataset
protected titletb as textbox
protected blogtext as textbox
private _addredirect as string
private _email as string
private _mode as blogmode
private _separatorcolor as color = color.black
＜browsable(true), _
category("behavior"), _
description("url to which the page should redirect after successful submission of a new blog entry."), _
editor("system.web.ui.design.urleditor", _
gettype(uitypeeditor))＞ _
public property addredirect() as string
get
return me._addredirect
end get
set(byval value as string)
me._addredirect = value
end set
end property
＜browsable(true), _
category("behavior"), _
description("email address the control will use for listing in new blog entries.")＞ _
public property email() as string
get
return me._email
end get
set(byval value as string)
me._email = value
end set
end property
＜browsable(true), _
category("behavior"), _
description("controls whether existing blogs are displayed, or fields for creating a new blog entry.")＞ _
public property mode() as blogmode
get
return me._mode
end get
set(byval value as blogmode)
me._mode = value
end set
end property
＜browsable(true), _
category("appearance"), _
description("controls the color of the line that separates blog entries when in display mode.")＞ _
public property separatorcolor() as color
get
return me._separatorcolor
end get
set(byval value as color)
me._separatorcolor = value
end set
end property
protected overrides sub oninit(byval e as eventargs)
loaddata()
mybase.oninit(e)
end sub
protected overrides sub createchildcontrols()
if not me._mode = blogmode.add then
displayblogs()
else
newblog()
end if
end sub
protected sub loaddata()
blogds = new dataset()
try
blogds.readxml(page.server.mappath("blog.xml"))
catch fnfex as filenotfoundexception
createblankfile()
loaddata()
end try
end sub
protected sub displayblogs()
dim blogdate as datetime
dim currentdate as datetime = new datetime()
dim blogrows as datarowcollection = _
blogds.tables(0).rows
dim blogdr as datarow
for each blogdr in blogrows
dim bdate as string = blogdr("date").tostring()
blogdate = new datetime _
(convert.toint32(bdate.substring(4, 4)), _
convert.toint32(bdate.substring(0, 2)), _
convert.toint32(bdate.substring(2, 2)))
if not currentdate = blogdate then
dim tempdate as label = new label()
tempdate.text = blogdate.tolongdatestring()
tempdate.font.size = fontunit.large
tempdate.font.bold = true
me.controls.add(tempdate)
me.controls.add _
(new literalcontrol("＜br/＞＜br/＞"))
currentdate = blogdate
end if
dim anchor as htmlanchor = new htmlanchor()
anchor.name = "#" + blogdr("anchorid").tostring()
me.controls.add(anchor)
dim title as label = new label()
title.text = blogdr("title").tostring()
title.font.size = fontunit.larger
title.font.bold = true
me.controls.add(title)
me.controls.add(new literalcontrol("＜p＞"))
dim blogtext as literalcontrol = _
new literalcontrol("＜div＞" & _
blogdr("text").tostring() & "＜/div＞")
me.controls.add(blogtext)
me.controls.add(new literalcontrol("＜/p＞"))
dim email as hyperlink = new hyperlink()
email.navigateurl = "mailto:" & _
blogdr("email").tostring()
email.text = "e-mail me"
me.controls.add(email)
me.controls.add(new literalcontrol(" "))
dim anchorlink as hyperlink = new hyperlink()
anchorlink.navigateurl = _
page.request.url.tostring() & "#" & _
blogdr("anchorid").tostring()
anchorlink.text = "link"
me.controls.add(anchorlink)
me.controls.add _
(new literalcontrol("＜hr color='" & _
colortranslator.tohtml(_separatorcolor) & _
"' width='100%'/＞＜br/＞"))
next
end sub
protected sub newblog()
dim title as label = new label()
title.text = "create new blog"
title.font.size = fontunit.larger
title.font.bold = true
me.controls.add(title)
me.controls.add(new literalcontrol("＜br/＞＜br/＞"))
dim titlelabel as label = new label()
titlelabel.text = "title: "
titlelabel.font.bold = true
me.controls.add(titlelabel)
titletb = new textbox()
me.controls.add(titletb)
me.controls.add(new literalcontrol("＜br/＞"))
dim blogtextlabel as label = new label()
blogtextlabel.text = "text: "
blogtextlabel.font.bold = true
me.controls.add(blogtextlabel)
blogtext = new textbox()
blogtext.textmode = textboxmode.multiline
blogtext.rows = 10
blogtext.columns = 40
me.controls.add(blogtext)
me.controls.add(new literalcontrol("＜br/＞"))
dim submit as button = new button()
submit.text = "submit"
addhandler submit.click, addressof me.submit_click
me.controls.add(submit)
end sub
protected sub submit_click(byval sender as object, _
byval e as eventargs)
ensurechildcontrols()
addblog()
end sub
protected sub addblog()
dim newblogdr as datarow
newblogdr = blogds.tables(0).newrow()
newblogdr("date") = formatdate(datetime.today)
newblogdr("title") = titletb.text
newblogdr("text") = blogtext.text
newblogdr("anchorid") = guid.newguid().tostring()
newblogdr("email") = _email
blogds.tables(0).rows.insertat(newblogdr, 0)
blogds.writexml(page.server.mappath("blog.xml"))
page.response.redirect(_addredirect)
end sub
protected function formatdate(byval dt as datetime) as string
dim retstring as string
retstring = string.format("{0:d2}", dt.month)
retstring &= string.format("{0:d2}", dt.day)
retstring &= string.format("{0:d2}", dt.year)
return retstring
end function
public sub createblankfile()
dim newxml as streamwriter = _
file.createtext(page.server.mappath("blog.xml"))
newxml.writeline("＜blogs＞")
newxml.writeline _
(" ＜!-- blog field describes a single blog --＞")
newxml.writeline(" ＜blog＞")
newxml.writeline(" ＜!-- date field contains" & _
" the creation date of the blog --＞")
newxml.writeline(" ＜date＞" & _
formatdate(datetime.today) & "＜/date＞")
newxml.writeline _
(" ＜title＞temporary blog＜/title＞")
newxml.writeline(" ＜!-- text field " & _
"should contain the blog text, including any " & _
"desired html tags --＞")
newxml.writeline(" ＜text＞this entry " & _
"indicates that the file blog.xml was not " & _
"found.a default version of this file has " & _
"been created for you.you can modify the " & _
"fields in this file as desired.if you set " & _
"the blog control to add mode (add the " & _
"attribute mode='add' to the control's " & _
"declaration), the control will " & _
"automatically populate the xml file when " & _
"you submit the form.＜/text＞")
newxml.writeline(" ＜!-- anchorid field " & _
"will be autopopulated by the control --＞")
newxml.writeline(" ＜anchorid＞＜/anchorid＞")
newxml.writeline(" ＜!-- email field should" & _
" contain the email address for feedback --＞")
newxml.writeline(" ＜email＞change this to a " & _
"valid email address＜/email＞")
newxml.writeline(" ＜/blog＞")
newxml.writeline("＜/blogs＞")
newxml.close()
end sub
end class
public class blogdesigner
inherits controldesigner
public overrides function getdesigntimehtml() as string
return "＜h1＞blog＜/h1＞＜hr/＞＜hr/＞"
end function
end class
