string - Textbox for price/cash/currency on C# -

i have problem haunting me while. tried solutions didn't worked.

i have textbox cash input ($999,99 example). need automatically input "," , "." display value correctly.

i tried 2 solutions. 1 of them this:

   private void tx_valorunidade_textchanged(object sender, eventargs e)     {         string value = tx_valorunidade.text.replace(",", "").replace("r$", "");         decimal ul;         //check indeed handling number         if (decimal.tryparse(value, out ul))         {             //unsub event don't enter loop             tx_valorunidade.textchanged -= tx_valorunidade_textchanged;             //format text currency             tx_valorunidade.text = string.format(system.globalization.cultureinfo.createspecificculture("pt-br"), "{0:c2}", ul);             tx_valorunidade.textchanged += tx_valorunidade_textchanged;         }     } 

the result, however, weird. words may fail on one, recorded video: http://www.screenr.com/2slh

the other 1 this:

    private void tx_valorunidade_keyup(object sender, keyeventargs e)     {           if (!string.isnullorempty(tx_valorunidade.text))           {               system.globalization.cultureinfo culture = new system.globalization.cultureinfo("en-us");               int valuebefore = int32.parse(tx_valorunidade.text, system.globalization.numberstyles.allowthousands);               tx_valorunidade.text = string.format(culture, "{0:n0}", valuebefore);               tx_valorunidade.select(tx_valorunidade.text.length, 0); *           }     } 

this 1 kinda works, there issue: if user wants insert somethink $10,00 can't. crashes after 5 numbers. video that: http://www.screenr.com/1slh

for original reference, got 2 codes other questions here.

how can fix it? using examples wrong? thought welcome.

i think better off when formatting when user moves next control, e.g. below. otherwise confusing text change user typing:

    private void textbox1_leave(object sender, eventargs e)     {         double value;         if (double.tryparse(textbox1.text, out value))             textbox1.text = string.format(system.globalization.cultureinfo.currentculture, "{0:c2}", value);         else             textbox1.text = string.empty;     }