View flashes when popToRootViewController - ios

Question

I am having a problem with popToRootViewController. I have a root view A and a table view B. And when a row is selected in the table view I pass a string back to the root view and depending on the string. I change the title of buttons on A.
I have made a very simple version of this and put it on gitHub at this link: https://github.com/spennyf/didSelect_test. I am doing this because it is very hard to explain until you actually run this on your phone of the simulator. And see the flash. I don't know why it is happening or how to fix it. Any help would be greatly appreciated I will also post most of the code below, but if you could see the flash for yourself I think it would help explain the problem. Heres the code:
viewControllerA.h
#import <UIKit/UIKit.h>
#interface ViewController : UIViewController
#property (strong, nonatomic) IBOutlet UIButton *btn1;
#property (strong, nonatomic) IBOutlet UIButton *btn2;
#property (strong, nonatomic) IBOutlet NSString *object;
#end
viewControllerA.m
#import "ViewController.h"
#interface ViewController ()
#end
#implementation ViewController
- (void)viewDidLoad
{
[super viewDidLoad];
// Do any additional setup after loading the view, typically from a nib.
}
- (void)didReceiveMemoryWarning
{
[super didReceiveMemoryWarning];
// Dispose of any resources that can be recreated.
}
-(void)viewWillAppear:(BOOL)animated {
NSLog(#"object: %#", _object);
if ([_object isEqualToString:#"object1"]) {
[_btn1 setTitle:#"new1" forState:UIControlStateNormal];
}
if ([_object isEqualToString:#"object2"]) {
[_btn2 setTitle:#"new2" forState:UIControlStateNormal];
}
}
#end
tableviewB.m
#import "TableViewController.h"
#import "ViewController.h"
#interface TableViewController () {
NSMutableArray *_objects;
}
#end
#implementation TableViewController
- (void)viewDidLoad
{
[super viewDidLoad];
_objects = [[NSMutableArray alloc] init];
NSDictionary *obj1 = [[NSDictionary alloc] initWithObjectsAndKeys:#"object1", #"title", nil];
NSDictionary *obj2 = [[NSDictionary alloc] initWithObjectsAndKeys:#"object2", #"title", nil];
// NSDictionary *obj3 = [[NSDictionary alloc] initWithObjectsAndKeys:#"rpi", #"title", nil];
[_objects addObject:obj1];
[_objects addObject:obj2];
}
#pragma mark - Table view data source
- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView
{
// Return the number of sections.
return 1;
}
- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
{
// Return the number of rows in the section.
return _objects.count;
}
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
static NSString *CellIdentifier = #"Cell";
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
if (cell == nil) {
cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleSubtitle reuseIdentifier:CellIdentifier];
cell.accessoryType = UITableViewCellAccessoryDisclosureIndicator;
}
//NSLog(#"%#", _objects);
cell.textLabel.text = [[_objects objectAtIndex:indexPath.row] objectForKey:#"title"];
return cell;
}
-(void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath {
ViewController *myController = (ViewController *)[self.navigationController.viewControllers objectAtIndex:0];
myController.object = [[_objects objectAtIndex:indexPath.row] objectForKey:#"title"];
[self.navigationController popToRootViewControllerAnimated:YES];
}
#end
Again thanks for the help.

Answer 1

There is no problem with your code. It is intended behavior for UIButtons of type UIButtonTypeSystem to flash when its title is changed.
A simple workaround is to set the type of your buttons to UIButtonTypeCustom.
Edit:
You can change the type of the button in Interface Builder: