ios - How do I put a UIActivityIndicatorView in a UIAlertController? -

we're moving away mbprogresshud because it's glitchy in our app, , doesn't have features such blocking user input or providing cancel button.

so, i've attempted implement swipesight's how display activity indicator in center of uialertcontroller?, , ran improper positioning of indicator:

^{it green because our app's tint green.}

as can see, it's not in white rectangle part of controller, grey background. uses similar "@62shark" solution:

// in implementation:  @property (nonatomic, strong) uiactivityindicatorview *spinner; @property (nonatomic, strong) uialertcontroller *alertcontroller;   // in init:  _alertcontroller = [uialertcontroller alertcontrollerwithtitle: @"loading"                                                          message: nil                                                   preferredstyle: uialertcontrollerstylealert]; _spinner = [uiactivityindicatorview new]; _spinner.translatesautoresizingmaskintoconstraints = false; _spinner.userinteractionenabled = false; _spinner.color = [themingassistant tintcolor]; _spinner.frame = _alertcontroller.view.bounds; _spinner.autoresizingmask = uiviewautoresizingflexiblewidth | uiviewautoresizingflexibleheight; [_spinner startanimating]; [_alertcontroller.view addsubview: _spinner];   // ...  - (void) showon: (uiviewcontroller *)target           title: (nsstring *)title         message: (nsstring *)message       cancancel: (bool)cancancel {     self.alertcontroller.title = title;     self.alertcontroller.message = message;      if (cancancel)     {         [self.alertcontroller addaction:[uialertaction actionwithtitle: @"cancel"                                                                  style: uialertactionstylecancel                                                                handler: ^(uialertaction *name){                                                                    [self customdismiss];                                                                }]];     }      nsdictionary *views = @{@"pending"   : self.alertcontroller.view,                             @"indicator" : self.spinner};     nsarray *constraints =     [nslayoutconstraint constraintswithvisualformat: @"v:[indicator]-(-50)-|"                                             options: 0                                             metrics: nil                                               views: views];     [constraints arraybyaddingobjectsfromarray:      [nslayoutconstraint constraintswithvisualformat: @"h:|[indicator]|"                                              options: 0                                              metrics: nil                                                views: views]];       [target presentviewcontroller: self.alertcontroller                          animated: true                        completion: nil]; } 

even if in white rectangle, fear might run text (also, when in there, want in middle-top, mbprogresshud does), i'll need way reserve space it.

so, question two-fold: how reserve space uiactivityindicatorview in uialertcontroller's white rectangle, , how place in there?

like jonasg mentioned here there property named contentviewcontroller , can use kvc access

example :

uiviewcontroller *v = [[uiviewcontroller alloc] init]; v.view.backgroundcolor = [uicolor redcolor];  [alertcontroller setvalue:v forkey:@"contentviewcontroller"]; 

so here how code should looks (tested , works fine) :

- (ibaction)buttonclicked:(id)sender {      self.alertcontroller = [uialertcontroller alertcontrollerwithtitle: @"loading"                                                            message: nil                                                     preferredstyle: uialertcontrollerstylealert];       [self.alertcontroller addaction:[uialertaction actionwithtitle: @"cancel" style: uialertactionstylecancel handler:nil]];       uiviewcontroller *customvc     = [[uiviewcontroller alloc] init];       uiactivityindicatorview* spinner = [[uiactivityindicatorview alloc] initwithactivityindicatorstyle:uiactivityindicatorviewstylegray];     [spinner startanimating];     [customvc.view addsubview:spinner];       [customvc.view addconstraint:[nslayoutconstraint                            constraintwithitem: spinner                            attribute:nslayoutattributecenterx                            relatedby:nslayoutrelationequal                            toitem:customvc.view                            attribute:nslayoutattributecenterx                            multiplier:1.0f                            constant:0.0f]];        [customvc.view addconstraint:[nslayoutconstraint                            constraintwithitem: spinner                            attribute:nslayoutattributecentery                            relatedby:nslayoutrelationequal                            toitem:customvc.view                            attribute:nslayoutattributecentery                            multiplier:1.0f                            constant:0.0f]];       [self.alertcontroller setvalue:customvc forkey:@"contentviewcontroller"];       [self presentviewcontroller: self.alertcontroller                          animated: true                        completion: nil];  } 

you can override -preferredcontentsize return custom size in view controller setting contentviewcontroller.

in our case it's customvc

result:

want text below indicator ?

i have created uiviewcontroller xib act custom controller our contentviewcontroller in first example have created view controller without xib file, can add views using interface builder, have added activity indicator , set constraints centered horizontally , vertically , label under activity indicator centered horizontally here interface builder:

we have less code now:

- (ibaction)buttonclicked:(id)sender {      self.alertcontroller = [uialertcontroller alertcontrollerwithtitle: nil                                                            message: nil                                                     preferredstyle: uialertcontrollerstylealert];      mycustomviewcontroller *v     = [[mycustomviewcontroller alloc] init];      [self.alertcontroller setvalue:v forkey:@"contentviewcontroller"];     [self presentviewcontroller: self.alertcontroller animated: true  completion: nil];  } 

result :