java - Empty JTextField User Input Error -

-

i'm trying create program takes user input through jtextfield , converts integer me calculate with. want prevent breaking program typing nothing jtextfield. how can detect when jtextfield empty? daniel

this spot use regular expression. here basic information on how use them.


Comments

Post a Comment

Popular posts from this blog

c++ - protocol buffers - generate NON-inline accessors -

-
we're using protocol buffers (2.4.1) in medium size embedded system w/ c# c++ code. use protobufs isolate our managed , native layers w/ easy maintain serialization layer (for curious, have used pinvoke, have run native code in separate process on test/simulators). our system has number of dll's, , have generated native protobuf code in it's own dll other parts of system can don't have link in generated code directly. the problem i'm having generated accessors inline , eg: inline const ::myprotoclassname::myfield& myprotoclassname::myfield() const { return myfield_ != null ? *myfield_ : *default_instance_->myfield_; } use generated api in size (the ' default_instance_ ' dereferenced , accessed if particular field not set). means can't link (lnk2001) clients using accessors because there not symbol default_instance_ i think typical use case protobufs have each component link in generated protobuf code (after all, serialization...
Read more

c# - issue attaching/adding an entity object which is detached from the DB Context? -

-
i new ef , seem have become bit stuck following issue.. i have following situation. two applications using same database, , have both loaded context @ same time displaying same information. application 1 goes , deletes entity , updates database savechanges. application 2 goes , saves same modified entity. we using updategraph recurse through tree , save entities database context. however, when come saving deleted entity, doesn't exist in db context obtained database want add database. i have tried doing add, gives multiplicity error trying add full tree context! any ideas please? the following code snippet updategraph extension method. ( http://github.com/refactorthis/graphdiff ) private static void recursivegraphupdate<t>(dbcontext context, t datastoreentity, t updatingentity, updatemember member) t:class { if (member.iscollection) { // dealing collection var updatevalues = (ienumerable)member.accessor.getvalue...
Read more