I am making an application with TabBar. But TabBarController is not RootViewController. In the Tab Bar there are 4 tabs. One of those tabs is history which is linked with a table view which shows history. I want to refresh that view every time when i click that so that i can get updated tableview. How can i do that? Thanks in advance.
use - (void) viewWillAppear:(BOOL)animated to update any content in your view.
- (void) viewWillAppear:(BOOL)animated {
[super viewWillAppear:animated];
// You code here to update the view.
}
This method will be called every time the view is about to be displayed.
below code added plz ^^
If you change a tabBarIndex, At the same time -(void)viewWillAppear called.
-(void)viewWillAppear:(BOOL)animated
{
// force the tableview to load
[tableView reloadData];
}
refer a Apple Sample Code: that is amazing great tutorial for you about UITabBarController
http://developer.apple.com/library/ios/#samplecode/TheElements/Introduction/Intro.html
Apple Sample Code is no added [super viewWillAppear:animated];
-(void)viewDidAppear:(BOOL)animated
{
[super viewDidAppear:YES];
if ([Globals sharedInstance].isFromFindSimiler)
{
[self.view addSubview:_findSimilerView];
[_historyTableView setFrame:CGRectMake(0, 85, 320, 490)];
}
else
{
[self history_webservice];
}
}
I have achieved this. In this case, whenever user tabs on History screen I call web service for history and update tableview.
instead of using (void)ViewDidLoad use viewWillAppear:(BOOL)animated
- (void) viewWillAppear:(BOOL)animated {
[super viewWillAppear:animated];
//your code
}
Related
i have a screen having navigation controller and text field. when i move next and come back i want the keyboard should be hidden in first screen. I am hiding keyboard like on textfield event.
- (BOOL)textFieldShouldReturn:(UITextField *)textField {
[textField resignFirstResponder];
return NO;
}
But how to do that in View related events so that whenever my view appears keyboard is hidden..
Pls guide/Help.
thanks in adv.
I think this is also a good way to remove keyboard with in iOS App if your UITextView or UITextField not connected through the IBOutlet.
If you want to Hide Keyboard with UIViewController LifeCycle Events like with viewWillAppear or etc. Follow this
-(void)viewWillAppear:(BOOL)animated {
[super viewWillAppear:animated];
[[self view] endEditing:YES];
}
Otherwise if you object connected using IBOutLet this code will work fine as you describe too.
[yourTextField resignFirstResponder];
Add this code to your ViewWillAppear :
for(id obj in self.view.subviews)
{
if([obj isKindOfClass:[UITextField class]])
{
[obj resignFirstResponder];
}
}
This would take in all the textfields in that particular view here it is the whole view and add the code you had written previously for removing the keyboard.
A good habit is to write this code in your screen's -viewWillDisappear. So, when you navigate from one screen to another at that time it will remove the keyboard from that screen.
- (void)viewWillDisappear:(BOOL)animated
{
[self.view endEditing:YES];
[super viewWillDisappear:animated];
}
For multiple textFields, it is better to use -endEditing for that particular view instead of -resignFirstResponder for any single textField. Take a look at my Answer.
//This is for Swift
override func viewWillAppear(animated: Bool)
{
self.view.endEditing(true)
}
The thing that you are doing wrong is , when you are moving back previous controller to the current controller , the keyboard is up due to the selected textfield of previous controller .
And in the current controller the code:
-(void)viewWillAppear:(BOOL)animated {
[super viewWillAppear:animated];
[[self view] endEditing:YES];
}
It will not work as no textfield is selected at this controller. So what you need to do is write the same code in the previous controller viewWillDisappear Method it will surely resolve your Problem .
- (void)viewWillDisappear:(BOOL)animated
{
[self.view endEditing:YES];
[super viewWillDisappear:animated];
}
I am using tab bar based iPhone application.I have set NSTimer in first two tabs.i want to invalidate this timer. so i am invalidating in viewDidDisappear. But when i am clicking on different tab, it will never call viewDidDisappear. I don't know how to call this method?please help me...thanking you in advance...
are you put [super viewWillDisappear:animated]; in viewWillDisappear some time it happaned becouse we forget to put this line in to viewWillDisappear
- (void) viewWillDisappear:(BOOL) animated {
[super viewWillDisappear:animated];
}
set time invalid in viewWillDisappear: method , like bellow..
-(void)viewWillDisappear:(BOOL)animated
{
[yourTimer invalidate];
yourTimer = nil;
}
I need to fully UNLOAD the flipview don't ask me why but i NEED to. i have tried [super release]; and it didnt work below is my back button and then the did finish. Please help me to unload the view.
on the first view which gets activated once the flipview has finished.
- (void)flipViewControllerDidFinish:(FlipViewController *)controller
{
[self dismissModalViewControllerAnimated:YES];
}
on the flip view which is a button that hides the flip view just hides doesn't unload
- (IBAction)Back:(id)sender
{
[self.delegate flipViewControllerDidFinish:self];
}
[myFlipViewController.view removeFromSuperview];
I need to hide something on the screen when the user has activates the application by switching it to the foreground.
I have tried inserting my code within applicationDidBecomeActive or applicationWillEnterForeground and although it runs OK the old screen with the text I want to hide is displayed momentarily.
How can I hide the field before the screen is redrawn?
Thanks
iphaaw
I think the problem is, iOS will capture a screenshot from your app in the moment it goes to the background, so the animation will work in an instant.
The only way in my opinion to do this is to hide / cover your view in moment the app goes to the background.
Write some code in applicationWillResignActive: to 'hide' whatever you need to hide.
I faced a similar situation but, instead of hiding, I wanted to show a block code screen to grant access. Anyway I think that the solution also applies to your needs.
I often implement a custom base view controller in my iOS applications. So instead of dealing with applicationDidBecomeActive: or applicationWillResignActive: I setup this view controller to listen for the equivalent notifications:
#interface BaseViewController : UIViewController
- (void)prepareForGrantingAccessWithNotification:(NSNotification *)notification;
- (void)grantAccessWithNotification:(NSNotification *)notification;
#end
#implementation BaseViewController
- (void)viewWillAppear:(BOOL)animated {
[super viewWillAppear:animated];
[self addNotificationHandler:#selector(grantAccessWithNotification:)
forNotification:UIApplicationDidBecomeActiveNotification];
[self addNotificationHandler:#selector(prepareForGrantingAccessWithNotification:)
forNotification:UIApplicationWillResignActiveNotification];
}
- (void)viewWillDisappear:(BOOL)animated {
[super viewWillDisappear:animated];
[[NSNotificationCenter defaultCenter] removeObserver:self];
}
- (void)prepareForGrantingAccessWithNotification:(NSNotification *)notification {
// Hide your views here
myCustomView.alpha = 0;
// Or in my case, hide everything on the screen
self.view.alpha = 0;
self.navigationController.navigationBar.alpha = 0;
}
- (void)grantAccessWithNotification:(NSNotification *)notification {
// This is only necessary in my case
[self presentBlockCodeScreen];
self.view.alpha = 1;
self.navigationController.navigationBar.alpha = 1;
...
}
#end
I have a strange problem with a UIView :
I want to show an Activity Indicator View that I created with Interface Builder to indicate long running activity.
In the viewDidLoad function of my principal viewController I init the ActivityIndicator View like this :
- (void)viewDidLoad {
[super viewDidLoad];
appDelegate = (MyAppDelegate *)[[UIApplication sharedApplication] delegate];
load = [[ActivityIndicatorViewController alloc] init];
...
When I push a button it call this IBAction :
- (IBAction)LaunchButtonPressed{
// Show the Activity indicator view.
[self.view addSubview:load.view];
// eavy work
[self StartWorking];
// Hide the loading view.
[load.view removeFromSuperview];
}
In the StartWorking function, I ask a request to an internet serveur and parse the XML file that it return me.
The problem is that if I Call my StartWorking function, the application do not start by showing the Activity Indicator view but with the StartWorking function.
Whereas if I remove the call to StartWorking function, the view is shown.
Is someone able to explain me why? :s
Have you tried to call the StartWorking method on a different thread?
Maybe its heavy process prevents other instructions to take place.
Look at the NSThread class, especially the detachNewThreadSelector:toTarget:withObject: method.
EDIT: About the pool problem, you need to create a pool in your StartWorking method, if it's called on a different thread:
- ( void )StartWorking
{
NSAutoreleasePool * pool = [ [ NSAutoreleasePool alloc ] init ];
/* Code here... */
[ pool release ];
}
Replace :
[self.view addSubview:load.view];
With :
[self performSelector:#selector(addLoadingSubview) afterDelay:0.1f];
And create the method :
-(void)addLoadingSubview{[self.view addSubview:load.view];}
Ok, I found a solution based on santoni answer :
- (IBAction)LaunchButtonPressed{
// Show the Activity indicator view.
[self performSelector:#selector(ShowActivityIndicatorView) withObject:nil afterDelay:0];
// eavy work
[self performSelector:#selector(StartWorking) withObject:nil afterDelay:2];
// Hide the loading view.
[load.view removeFromSuperview];
}
The Activity Indicator view is dislayed before the call to the eavy function.
Thank's for answering.