c# - How does the debugger get type information about an object initialized to null? -

-


c# - How does the debugger get type information about an object initialized to null? -

if object initialized null, not possible type information because reference doesn't point anything.

however, when debug , hover on variable, shows type information. static methods shown, still, seems know type. in release builds.

does debugger utilize other info reflection of sort find out datatype? how come knows more i? , if knows this, why isn't capable of showing datatype in nullreferenceexception?

it seems you're confusing type of reference type of value points to. type of reference embedded dll metadata , readily accessible debugger. there aditional info stored in associated pdb debugger leverages provide improve experience. hence null references debugger can determine info type , name.

as nullreferenceexception. tell type on querying field / method ... possibly. i'm not familiar internals of part of clr there doesn't seem inherent reason why couldn't so.

but i'm not sure added cost clr worth benefit. share frustration lack of info null ref exception. more type involved want names! don't care icomparable, wanted know leftcustomer.

names somethnig clr doesn't have access portion of them live in pdb , not metadata. hence can't provide them great reliability (or speed)

c# .net debugging

Comments

Post a Comment

Popular posts from this blog

How do I check if an insert was successful with MySQLdb in Python? -

-
How do I check if an insert was successful with MySQLdb in Python? - i have code: cursor = conn.cursor() cursor.execute(("insert new_files (videos_id, filename, " "is_processing) values (%s,%s,1)"), (id, filename)) logging.warn("%d", cursor.rowcount) if (cursor.rowcount == 1): logging.info("inserted values %d, %s", id, filename) else: logging.warn("failed insert values %d, %s", id, filename) cursor.close() fun is, cursor.rowcount always one, though updated database create videos_id unique key. is, insert fails because in tests same videos_id going appear (and when check database, nil inserted). whatever reason, rowcount 1 - logging.warn have spits out rowcount of 1. so, question: can utilize rowcount work out if insert went fine? if so, (presumably) doing wrong? otherwise, how check if insert went fine? your code not commit after modifications (your modifications rolled back). should...
Read more

delphi - blogger via idHTTP : error 400 bad request -

-
delphi - blogger via idHTTP : error 400 bad request - i'm trying post blogger using idhttp component, however, i'm getting "http/1.0 400 bad request" error. procedure tform1.button1click(sender: tobject); var request,response,req : tstringlist; auth,blogid : string; begin blogid := '00000000000000000000000'; request := tstringlist.create; response := tstringlist.create; req := tstringlist.create; idhttp1.request.connection := 'keep-alive'; idhttp1.request.contenttype := 'application/x-www-form-urlencoded'; idssliohandlersocket1.ssloptions.method := sslvsslv23; request.clear(); request.values['accounttype'] := 'google'; request.values['email'] := 'xxx@gmail.com'; request.values['passwd'] := 'yyy'; request.values['service'] := 'blogger'; response.text :=idhttp1.post('https://www.google.com/accounts/clientlogin',request); auth := resp...
Read more

postgresql - ERROR: operator is not unique: unknown + unknown -

-
postgresql - ERROR: operator is not unique: unknown + unknown - i have postgis database , have compute new values rows in new column. these values should average of values of several columns. query: insert bdps (da_m) values (avg('da_1'+'da_2'+'da_3'+'da_4'+'da_5'+'da_6'+'da_7')); in query bdps database, da_m new column , da_1 da_7 existing columns have double precision type. da_m created using alter table bdps add together column da_m double precision; i next error: error: operator not unique: unknown + unknown line 2: values (avg('da_1'+'da_2'+'da_3'+'da_4'+'da_5'+'da_6'+'da_7... ^ hint: not take best candidate operator. might need add together explicit type casts. ********** error ********** error: operator not unique: unknown + unknown sql state: 42725 hint: not take best candidate operator. might need add togethe...
Read more