Maxchars of textinput verifies the number of halfwidth and fullwidth characters

The textinput component has the maxchars attribute to limit the number of input texts, but does not support halfwidth and fullwidth. I checked the information online and finally got some results. The following example is provided for your reference:

 

<? XML version = "1.0" encoding = "UTF-8"?> <Br/> <s: Application xmlns: FX = "http://ns.adobe.com/mxml/2009" <br/> xmlns: S = "Library: // ns.adobe.com/flex/spark" <br/> xmlns: MX = "Library: // ns.adobe.com/flex/mx" <br/> minwidth = "955" minheight = "600"> <br/> <FX: SCRIPT> <br/> <! -- [CDATA [<br/> Import flash. desktop. clipboard; <br/> Import flash. desktop. clipboardformats; </P> <p> Import flashx. textlayout. edit. selectionstate; <br/> Import flashx. textlayout. operations. inserttextoperation; <br/> Import flashx. textlayout. operations. pasteoperation; </P> <p> Import spark. events. textoperationevent; <br/>/** <br/> * changinghandler <br/> * text input ing, full-width half-width text count verification <br/> * @ Param textoperat Ionevent event <br/> * @ return void <br/> ***/<br/> protected function changinghandler (Event: textoperationevent ): void <br/>{< br/> var target: textinput = event. currenttarget as textinput; </P> <p> If (target. maxchars <= 0) return; </P> <p> // original text <br/> var oldtext: String = target. text; </P> <p> // newly appended text <br/> var addtext: string; </P> <p> // The length of the selected text (the text to be overwritten) <br/> var dellen: int; </P> <p> // total text length <br/> var totallen: I NT; </P> <p> var insertop: inserttextoperation; <br/> var pasteop: pasteoperation; </P> <p> var selectstate: selectionstate; </P> <p> If (event. operation is inserttextoperation) {<br/> // text insertion <br/> insertop = event. operation as inserttextoperation; </P> <p> // obtain the newly appended text. <br/> addtext = insertop. text; </P> <p> // obtain the object of the selected text <br/> selectstate = insertop. deleteselectionstate; </P> <p> dellen = selectstate? Getbytelenbystr (oldtext. substring (selectstate. absolutestart, selectstate. absoluteend): 0; </P> <p> // total length <br/> totallen = getbytelenbystr (oldtext) + getbytelenbystr (addtext)-dellen; </P> <p> If (totallen> target. maxchars) event. preventdefault (); </P> <p>} else if (event. operation is pasteoperation) {<br/> // text paste <br/> pasteop = event. operation as pasteoperation; </P> <p> // obtain the pasted text <br/> addtext = clipboar D. generalclipboard. getdata (clipboardformats. text_format) as string; </P> <p> // obtain the object of the selected text <br/> selectstate = pasteop. originalselectionstate; </P> <p> dellen = selectstate? Getbytelenbystr (oldtext. substring (selectstate. absolutestart, selectstate. absoluteend): 0; </P> <p> // total length <br/> totallen = getbytelenbystr (oldtext) + getbytelenbystr (addtext)-dellen; </P> <p> If (totallen> target. maxchars) event. preventdefault (); </P> <p >}// if event. operation End </P> <p >}</P> <p>/** <br/> * getbytelenbystr <br/> * Get the length of string bytes (1 byte) 2 bytes) <br/> * @ Param string Val <br/> * @ Param String charset <br/> * @ return uint <br/> ***/<br/> Public Function getbytelenbystr (VAL: String, charset: String = "utf8 "): uint <br/>{< br/> If (! Val) return 0; </P> <p> var bytearr: bytearray = new bytearray (); </P> <p> bytearr. writemultibyte (Val, charset); <br/> bytearr. position = 0; </P> <p> return bytearr. length; <br/>}</P> <p>] --> <br/> </FX: SCRIPT> </P> <p> <FX: declarations> </P> <p> </FX: declarations> </P> <p> <s: layout> <br/> <s: verticallayout paddingtop = "10" paddingleft = "10"/> <br/> </S: layout> </P> <p> <s: label text = "maxchars for text input halfwidth and fullwidth"/> </P> <p> <s: hgroup verticalalign = "bottom"> <br/> <s: textinput changing = "changinghandler (Event) "width =" 100 "maxchars =" 10 "/> <br/> <s: label text = "10 characters in width and 5 Characters in width"/> <br/> </S: hgroup> </P> <p> </s: application> <br/>