ASP.NET设计控件净化网站语言-.NET教程,Asp.Net开发

＜body＞

＜h1＞语言净化控件实例＜/h1＞＜br＞
＜form runat=server＞
＜custom:composite id = “composite” oncheck = “checktext”
filename = “bad_words.xml” runat = server/＞＜/form＞＜/body＞
＜/html＞

namespace customcontrols
public class composite
inherits control
implements inamingcontainer
private _filename as string = “bad_words.xml”
private label as label
private box1 as textbox

public property filename() as string
get
return _filename
end get
set
_filename = value
end set
end property

以用户提交的文本内容为输入参数。如果用户提交的内容包含攻击性言辞，
则返回修改后的版本，
否则，直接返回原始的文本。
public function checkstring(inputstring as string) as string
dim alwordlist as new arraylist
dim xmldocpath as string = mappathsecure(“bad_words.xml”)
dim xmlreader as xmltextreader = new xmltextreader(xmldocpath)
dim element as string
dim output as string
dim asterisks as string = “*************************”

将定义攻击性言辞的xml文件内容读入到一个arraylist
while (xmlreader.read())
if xmlreader.nodetype=xmlnodetype.text then
alwordlist.add(xmlreader.value)
end if
end while
xmlreader.close()

检查用户提交的文本内容，将攻击性言辞替换为适当数量的星号
for each element in alwordlist
inputstring=inputstring.replace(element,
asterisks.substring(1, (element.length)))
next

return inputstring

end function

public property text() as string
get
该方法首先检查childcontrolscreated属性的当前值。如果该值是false，
则调用createchildcontrols方法
ensurechildcontrols()
return label.text
end get
set
ensurechildcontrols()
label.text = value
end set
end property

public event check as checkeventhandler

protected overridable sub oncheck(ce as checkeventargs)
raiseevent check(me, ce)
end sub

创建composite控件的子控件
protected overrides sub createchildcontrols()

controls.add(new literalcontrol(“＜h3＞请在下面输入文字内容: “))

文本输入框
dim box1 as new textbox()
box1.text = “”
controls.add(box1)

controls.add(new literalcontrol(“＜/h3＞”))

按钮
dim button1 as new button()
button1.text = “提交”
controls.add(new literalcontrol(“＜br＞”))
controls.add(button1)

将一个事件句柄加入新创建的按钮对象
addhandler button1.click, addressof me.buttonclicked

controls.add(new literalcontrol(“＜br＞＜br＞”))
label = new label()
label.height = unit.pixel(50)
label.width = unit.pixel(500)
label.text = “”
controls.add(label)
end sub

protected overrides sub onprerender(e as eventargs)
ctype(controls(1), textbox).text = “”
end sub

private sub buttonclicked(sender as [object], e as eventargs)
oncheck(new checkeventargs(ctype(controls(1), textbox).text,
checkstring(ctype(controls(1), textbox).text)))
end sub
end class
end namespace

public sub new(string1 as string, string2 as string)
if string1=string2 then
_match = true
end if
end sub

public readonly property match() as boolean
get
return _match
end get
end property
end class

public delegate sub checkeventhandler(sender as object, ce as checkeventargs)
end namespace