add maxline restriction in single line mode textCtrl. let textctrl will fire wxEVT_TEXT_MAXLEN and not recive the chars when the text length beyond the maxlength

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@77819 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

tests/controls/textctrltest.cpp

@@ -223,6 +223,7 @@ void TextCtrlTestCase::MaxLength()
     EventCounter maxlen(m_text, wxEVT_TEXT_MAXLEN);
 
     m_text->SetFocus();
+    wxYield();
     m_text->SetMaxLength(10);
 
     wxUIActionSimulator sim;