ios - Swift 3: prepare(for:sender:) -

-



this question has answer here:

i have simple entity:

extension team {  @nonobjc public class func fetchrequest() -> nsfetchrequest<team> {     return nsfetchrequest<team>(entityname: "team") }  @nsmanaged public var name: string? @nsmanaged public var phone: string? @nsmanaged public var department: string? @nsmanaged public var position: string?  }

picture easy understanding:

enter image description here

i load current entity core data app successfully. furthermore, have uitableviewcontroller property members (it's storage of fetch result team entity).

var members: [team] = []

after app launching (viewdidload(_:)) members.count equal 7 , right. also, these elements of members using uitableview in uitableviewcontroller:

enter image description here

my task open detailed view controller retrieve data tapped cell. delegation use classic prepare(for:sender:) method in uitableviewcontroller (who segue.source in current case):

// mark: - navigation  extension teamlistviewcontroller {  override func prepare(for segue: uistoryboardsegue, sender: any?) {     guard segue.identifier == segueidentifier,         let memberdetailsviewcontroller = segue.destination as? memberdetailsviewcontroller else {         fatalerror("wrong destination!")     }      guard let selectedindex = tableview.indexpathforselectedrow?.row else {         fatalerror("out of range")     }      guard let name       = members[selectedindex].name,           let phone      = members[selectedindex].phone,           let department = members[selectedindex].department,           let position   = members[selectedindex].position else {          fatalerror("no correct data")     }      memberdetailsviewcontroller.membernamelabel.text!        = name     memberdetailsviewcontroller.memberphonenumberlabel.text! = phone     memberdetailsviewcontroller.memberdepartmentlabel.text!  = department     memberdetailsviewcontroller.memberpositionlabel.text!    = position  }  }

so, app launches, tap cell whichever want open more details and.. app crashes!

fatal error: unexpectedly found nil while unwrapping optional value

enter image description here

however, variables (name, phone, department, position) ok. values!

enter image description here

oh, yes. try retrieve data uilabels in memberdetailsviewcontroller below:

// mark: - iboutlets @iboutlet weak var membernamelabel:        uilabel! @iboutlet weak var memberphonenumberlabel: uilabel! @iboutlet weak var memberdepartmentlabel:  uilabel! @iboutlet weak var memberpositionlabel:    uilabel!

what can problem here?

because of set data in prepare(for segue: uistoryboardsegue, sender: any?) method in teamlistviewcontroller memberdetailsviewcontroller not loaded thats way got nil.

my suggestion is: add object var members: team? in memberdetailsviewcontroller , pass teamlistviewcontroller error not appear.





wiki

Comments

Post a Comment

Popular posts from this blog

Asterisk AGI Python Script to Dialplan does not work -

-
i'm stuck project have check database of sip extension incoming caller id , dial sip extension. below receive when run script on asterisk cli. -- registered sip '9125' @ 192.168.1.102:50142 > saved useragent "zoiper rv2.8.40" peer 9125 [2017-08-22 13:53:33] notice[5095]: chan_sip.c:24558 handle_response_peerpoke: peer '9125' reachable. (17ms / 2000ms) == using sip rtp tos bits 184 == using sip rtp cos mark 5 -- executing [0112617769@from-trunk:1] answer("sip/obitrunk1-0000000d", "") in new stack > 0x1ca50d0 -- probation passed - setting rtp source address 192.168.1.98:16834 -- executing [0112617769@from-trunk:2] agi("sip/obitrunk1-0000000d", "test.py") in new stack -- launched agi script /var/lib/asterisk/agi-bin/test.py args: ['/var/lib/asterisk/agi-bin/test.py'] env line: agi_request: test.py env line: agi_channel: sip/obitrunk1-0000000d env line: agi_language: en env line: a
Read more

python - Read npy file directly from S3 StreamingBody -

-
i have many .npy (numpy) , .json files saved in s3, need download , load these files. for json files downloading files , loading dictionary using following code: obj = s3.object(bucket, key) response = obj.get() body = response['body'].read().decode('utf-8') data = json.loads(body) that way avoid writing .json file disk , reading it. now want same .npy files, equivalent? currently downloading file, saving temp file on disk , loading np.load avoid if possible. following https://stackoverflow.com/a/28196540/3509999 : obj = s3.object(bucket, key) io.bytesio(obj.get()["body"].read()) f: # rewind file f.seek(0) arr = np.load(f) wiki
Read more

kotlin - Out-projected type in generic interface prohibits the use of metod with generic parameter -

-
i start using kotlin , defined interface this: interface aadapter<vh : recyclerview.viewholder> { fun oncreateaviewholder(parent: viewgroup): vh fun onbindaviewholder(v: vh, position: int) } and when try use on code: class klasa ( private val adapter: aadapter<*> ) { fun dosth(){ //... val vh = this.adapter.oncreateaviewholder(parent) //on below line error adapter.onbindaviewholder(v, position) //... } } i error out-projected type 'aadapter<*>' prohibits use of 'public abstract fun onbindaviewholder(v: t, position: int): unit i tied add "in" or "out" definition i'm confused. how allow it. replace aadapter<*> aadapter<recyclerview.viewholder> . class klasa ( private val adapter: aadapter<recyclerview.viewholder> ) { // ... because have declared aadapter has type parameter vh type subclass of recyclerview.
Read more