wpf - TwoWay binding doesn't update controls -

the simplest example think of following:

textbox tb1 = new textbox(); textbox tb2 = new textbox();  this.content = new stackpanel() { children = { tb1, tb2 } };  binding binding = new binding("text") {     mode = bindingmode.twoway,     source = tb1,     updatesourcetrigger = updatesourcetrigger.propertychanged };  tb2.setbinding(textblock.textproperty, binding); 

when start application expect textboxes update text other textbox's text changes. neither source textbox nor target textbox updates text when changing other textbox. is there reason strange behavior , might there workaround?

(for specific reasons cannot use xaml, bindings worked me)

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update: when changing text of 1 of textboxes first time, output window says the thread 0x#### has exited code 259 (0x103).

you're using wrong dependencyproperty.

tb2.setbinding(**textblock**.textproperty, binding); 

copied code works expected when using textbox.textproperty