vb.net - .NET COM assembly interacting with Excel via BackgroundWorker -

-

i writing (and teaching myself how write) experimental assembly in vb.net 3.5 exposed via com , called excel vba code initiate instance of class traps excel events , perform functions on active workbook in excel.

to initiate class, reference excel application passed vba (i using pia excel in assembly).

i needed perform time-consuming operation on active workbook assembly decided use backgroundworker in winform can display progress dialog operation whilst operation completes in background.

i know if there problems interacting excel via com using background worker in way? reason asking main class in assembly holds reference excel application object, , passed backgroundworker can determine active workbook , perform operations on it. accessing workbook (not other objects) through 1 procedure.

for reason have in head excel might not - right?

if refering this:

  • getting method call vba vb.net code
  • spin off new thread (or worker thread) , handing on reference workbook (or excel.application, range; doesn't matter) (via parameters, statics... doesn't matter)
  • use original thread show ui while background thread accesses excel

then, no; cannot that.

excel vba sta environment. access excel object model, in , out, must happen same thread. don't pick thread either; has thread called method begin with.

to run code accessing excel worker thread, have "marshal" interface pointer worker thread. mashalling creates pair of com wrappers (called 'proxy/stub' pairs) shuttle method call accross threads needed - similar happens when use form.invoke() method in .net. don't know off top of head how in .net. not first approach anyway.

another alternative not access excel object worker thread, use helpers in main form object (you want form, don't you?). let worker thread call helpers via form.invoke() make sure run ui thread (the thread vba used call you). functionally same first alternative, except .net work, instead of com.

a third approach, not use worker threads @ - vb way: create ui 1 , thread; show it, , work load event of form. call application.doevents() once in while (a few times second) let ui operate reseamblance of smoothness.

a fourth alternative turn problem around. use brand new thread instead of pool thread (which backgroundworker) , handle ui there. reverse roles here: main thread fancy work, while thread creates form , shows ui. again, make sure use form.invoke() update progress window. make sure dispose() thread when you're done. might preferred approach.

or use hourglass mouse pointer... how "slow" "slow"?


Comments

Post a Comment

Popular posts from this blog

linux - Mailx and Gmail nss config dir -

-
i trying send mail linux command line using mailx command. can send local domain no problem want set mail send gmail account receive mail sent gmail account. after configuring mail.rc so: account gmail { set smtp=smtps://smtp.gmail.com:587 set smtp-auth=login set smtp-auth-user=username@gmail.com set smtp-auth-password=password set ssl-verify=ignore } i error: resolving host smtp.gmail.com . . . done. connecting 74.125.25.109 . . . connected. missing "nss-config-dir" variable. "/home/username/dead.letter" 11/354 . . . message not sent. after looking "nss-config-dir" here , located certn.db , keyn.db files , added mail.rc so: account gmail { set smtp=smtps://smtp.gmail.com:587 set smtp-auth=login set smtp-auth-user=username@gmail.com set smtp-auth-password=password set ssl-verify=ignore set nss-config-dir=/home/user/.mozilla/firefox/location.default } now when try send mail using command: echo "sent gmail account" | mailx -v -a
Read more

c# - Is it possible to remove an existing registration from Autofac container builder? -

-
something along lines: builder.registertype<mytype>().as<itype>(); builder.registertype<mytype2>().as<itype>(); builder.deregistertype<mytype>().as<itype>() var container = builder.build(); var types = container.resolve<ienumerable<itype>>(); assert.istrue(types.count == 1); assert.istrue(types[0].gettype == typeof(mytype2)); scenario: go through bunch of assemblies , go register types want make sure have 1 implementation of given type. need before create container. track on own nice if autofac me bit. this cannot done directly using containerbuilder , unless start on new one. mind you, having first built container should able construct new container filtering away unwanted types , reusing registrations first container. this: ... var container = builder.build(); builder = new containerbuilder(); var components = container.componentregistry.registrations .where(cr => cr.activator.limittype != typ
Read more

php - Mysql PK and FK char(36) vs int(10) -

-
i have read mysql can handle indexes , searches better if tables keys integers rather char(36) uuid's. is worth converting int(10)? note: use 1 server , have have plans use multiple databases concurrently therefore removing 1 of big reasons using uuid. our tables innodb if makes difference. thanks in advance. usually rdbms can handle integer keys pk more efficient, other datatypes. reason how build index column, yes: long dont require string (or other typed) keys, should use integers. however: char(36) , int(10) far away being equal, because int(10) much smaller, char(36). dont know, if require many different keys, should keep in mind. update, complete last paragraph: int(10) 32-bit, char(36) 36 - ^byte^ (= 288-bit). not mean, int consumes less space, means, char(36) has 4 times more different keys.
Read more