In a tabbar view when I call the tab to load useing self.tabBarController.selectedIndex the viewWillAppear is not called If i am been to the tab before hand is there a way to force the view to reload.
self.tabBarController.selectedIndex = 3;
[self.tabBarController.selectedViewController viewDidAppear:YES];
I was also thanking of dumping memory ever time i change tab's and that way when i get back to that view it reloads from the database.
you can implement
- (void)tabBarController:(UITabBarController *)tabBarController didSelectViewController:(UIViewController *)viewController
in the UITabBarControllerDelegate (probably your app delegate). Then in there you can manually call the methods you want on whichever index's viewController you selected.
Related
I would like to know when we are setting setSelectedIndex for uitabbbarviewcontroller,
Which delegate method will be called.
In my app, i have list of songs to purchase.when user taps buy button for any song, i will show the downloading tab.for that i am setting [self.tabBarController setSelectedIndex:3];there i am showing the song details and progressview that how much is downaloded etc.
This is fine upto this.in the meanwhile of downaloding poem the user can go and tap buy another poem.
here i want to reload the tableview.but i dont know in which delegate method i should call reload data for tableview.
I tried viewwillappear and viewdidappear. but these are not called.
So please tell me which delegate method will be called.
Thanks a lot
override UITabBarController setSelectedIndex:
-(void)setSelectedIndex:(NSUInteger)selectedIndex
{
//must call super function.
[super setSelectedIndex:selectedIndex];
[self myMethod];
}
- (void)tabBarController:(UITabBarController *)tabBarController didSelectViewController:(UIViewController *)viewController
{
[self myMethod];
}
- (void)tabBarController:(UITabBarController *)tabBarController didSelectViewController:(UIViewController *)viewController;
is called only when user taps it, when you programmatically set this, it is not called.
You can fire a custom delegate method or notification as soon as you do it programmatically and do what ever you need to do...
If I normally load up a UITabBarController and switch between views, it calls the viewWillAppear of each view controller.
But it is not so.
I want to switch to another tab as soon as another tab is touched.
If I specify a tab to load up - for example [self.tabBarController setSelectedIndex:0] in the viewWillAppear of one of the tabs (say tab 4)... It goes immediately back to tab 0.
But after that.... it does not call the viewWillAppear on any of the tabs when I switch between them.
For example, if I again go to tab 4, it does not come back to tab 0. I expect it to by a never ending cycle as I expect tab 0 to load up as soon as tab 4 is touch.
But it runs JUST ONCE !!
Why ??
Note: Question has been edited.
I think I found a solution. It works every time you click on your tab and it calls viewWillAppear on both tabs.
You can do this in your AppDelegate (or somwhere else in UITabBarController's delegate):
- (void)tabBarController:(UITabBarController *)tabBarController didSelectViewController:(UIViewController *)viewController
Sample code:
- (void)tabBarController:(UITabBarController *)tabBarController didSelectViewController:(UIViewController *)viewController {
if([self.tabBarController.viewControllers indexOfObject:viewController] == 1) {
[self.tabBarController setSelectedIndex:0];
}
}
setting the selectedIndex won't change the selectedViewController. You will have to change selectedViewController itself. Look at the documentation for more details.
Hi
I am trying to add and remove tab bar elements dynamically. There are two arrays. One is shown first with an added tabbaritem with name "More" and other array is added to the tabbar when user presses More. User can come back to first array by pressing Less tabbaritem in second array. Problem is that when i frequently press More and Less tabbaritems in sequence More, Less, More, Less, More, Less - The app crashes after last Less. Array seems ok to me and so is tabbar controller. I am not able to figure out the problem.
Below is the code of tab bar delegate method.
- (void)tabBarController:(UITabBarController *)tabBarController didSelectViewController:(UIViewController *)viewController {
NSLog(#"selected view controller is :%#",viewController);
if(viewController.view.tag == -1){
[self.tabBarController setViewControllers:self.level2TabBarItems animated:YES];
[self.tabBarController setSelectedIndex:0];
}else if(viewController.view.tag == -2){
[self.tabBarController setViewControllers:self.level1TabBarItems animated:YES];
[self.tabBarController setSelectedIndex:0];
}
}
Can anyone please let me know where I am doing wrong?
Best Regards
I had similar problem. I guess that you construct new instance of VC in your array, so frequently switching more/less causes calling method from the old instance (is not replaced yet at that moment).
Unfortunatelly setViewControllers method (as documentation say) automatically remove old view controllers calling dealloc and it seems that there is no other way to reuse them.
In your case you can try to disable selecting tabs until tabBarController:didSelectViewController: execute implementing (I didn't test it):
- (void)tabBarController:(UITabBarController *)tabBarController didSelectViewController:(UIViewController *)viewController {
self.selectLock = YES;
// your code
self.selectLock = NO;
}
- (BOOL)tabBarController:(UITabBarController *)tabBarController shouldSelectViewController:(UIViewController *)viewController {
return !self.selectLock;
}
Make comment NSLog here. This is not proper format to print this.
May be your array's are empty. Try to set a breakpoint and you will find the solution which line is causing the crash.
I think Both if and else if are not satisfied with this condition
Just Check your Tag with this NSLog(#"%d",viewController.view.tag);
I've been reading through forum posts and banging my head for over 2hrs now and hopefully someone can help point me in the right direction.
I am using the UITabBarController and have 4 root views associated to it.
In the first view, the user can take a picture (UIImagePicker), after which the second view is displayed programmatically. Once the second view is displayed I want to make an ajax request to a server.
I am able to sucessfully select/display the second view with the following code:
self.tabBarController.selectedIndex = 1;
However the UITabBarControllerDelegate method (which is successfully called upon user tabBarContoller touches):
- (void)tabBarController:(UITabBarController *)tabBarController didSelectViewController:(UIViewController *)viewController
is not called, as Apple tabBarController:didSelectViewController documentation states:
In versions of iOS prior to version 3.0, this method is called only when the selected view controller actually changes. In other words, it is not called when the same view controller is selected. In addition, the method was called for both programmatic and user-initiated changes to the selected view controller.
So my question is: "How can I execute some code & make a request after programmatically switching to second view?"
I also tried putting traces in:
-(void)viewDidAppear
-(void)ViewWillAppear
-(void)viewDidLoad
but none of those are called when tabBarController.selectedIndex is set.
Many Thanks
viewWillAppear should be called.. I just tested it.
Another solution: use the UITabBarControllerDelegate with
- (void)tabBarController:(UITabBarController *)tabBarController didSelectViewController:(UIViewController *)viewController
for tracking changes.
I'm using a TabBarController to select the first view of that spec. part. From this I've to push other views which have to removed later. Example (ReviewDetailController is an UIViewController):
ReviewDetailController *ctr = [[ReviewDetailController alloc] initWithNibName:#"ReviewDetail" bundle:nil];
... do some initializing and then
self.tabBarController.selectedViewController = ctr;
[ctr release];
This works, but I find no way to go back to the previous view.
Because it is not a navigationController, I can't use pushViewController and later popViewController.
But to push and to pop is what I really need.
I don't know if I did understand this rightly, but maybe you can use this
- (void)tabBarController:(UITabBarController *)tabBarController
didSelectViewController:(UIViewController *)viewController;
Store your topfrontViewController and you can switch between them.
Remember to set the delegate.