I have view controller with UIImageView . In view did load i want to set image on image view for particular time interval.After that image view should be cleared and application should switch to next screen. I have tried following code which is not working:
welcomeImage.image=[UIImage imageNamed:#"abc.png"];
sleep(5);
homeScreenController *controller=[[homeScreenController alloc]initWithNibName:#"homeScreenController" bundle:nil];
controller.modalTransitionStyle=UIModalTransitionStyleCrossDissolve;
[self presentModalViewController:controller animated:YES];
In this case it is sleeping before view did load and it is not going to the next screen also. So what is wrong with the code?
Use the below code/..
- (void)viewDidLoad
{
[super viewDidLoad];
[self performSelector:#selector(goToNextView) withObject:nil afterDelay:5.0];
}
- (void)goToNextView
{
homeScreenController *controller=[[homeScreenController alloc]initWithNibName:#"homeScreenController" bundle:nil];
controller.modalTransitionStyle=UIModalTransitionStyleCrossDissolve;
[self presentModalViewController:controller animated:YES];
}
The easiest solution is to fire a event after a time. I would recommend using performSelector.
- (void) hide {
//For example.
[self dismissModalViewController];
}
- (void) viewDidLoad {
//Setup my image.
[self performSelector:#selector(hide) withObject:nil afterDelay:3];
}
you can use NSTimer
something like this
- (void) viewDidLoad {
.......
NSTimer *timer = [[NSTimer scheduledTimerWithTimeInterval:(2.5)
target:self selector:#selector(hideImage)
userInfo:nil repeats:NO] retain];
....
}
- (void)hideImage
{
yourImage.hidden = YES;
}
Also, you made a sleep(5) inside the Main Thread, that's bad.
try something like
[self performSelectorOnBackground:#selector(hide) withObject:nil]
and do the thing you want (and the sleep(5)) inside the method -(void)hide like
-(void) hide {
sleep(5)
// ...
}
Good luck ;)
Related
In one stack I am displaying the MBProgressHUD and if by using the other stack when some calculation called I want MBProgressHUD to remove from the view but it is not been removed from the hud ..check what mistake I am doing..
first stack called LoginViewController.m
- (void)viewWillAppear:(BOOL)animated {
[super viewWillAppear:animated];
[MBProgressHUD showHUDAddedTo:self.view animated:YES];
}
-(void)myTask {
// Do something usefull in here instead of sleeping ...
[MBProgressHUD hideHUDForView:self.view animated:YES];
[self.hud hide:YES];
self.hud=nil;
[self.hud removeFromSuperview];
//[self.hud showWhileExecuting:#selector(myTask1) onTarget:self withObject:nil animated:YES];
}
now theViewController get calls but view will be same Previous and
after some calculation and I want that in ViewController I want to remove theHUD from the view by calling the method in the LoginViewController..check code
- (void)didReceiveResponseFromServer:(NSString *)responseData
{
login=[[LoginViewController alloc]init];
[self.login myTask];
}
Set UP MBProgressHUD
- (void) setupHUD
{
//setup progress hud
self.HUD = [[MBProgressHUD alloc] initWithFrame:self.window.bounds];
[self.SpurView addSubview:self.HUD]; // add it as here.
self.HUD.dimBackground = YES;
self.HUD.minSize = CGSizeMake(150.f, 150.f);
self.HUD.delegate = self;
self.HUD.labelText = #"Loading...";
}
Then use for hide [self.HUD hide:YES]; as describe in your code .
like me ,
I tyr [MBProgressHUD hideHUDForView:bAnimatedView animated:YES]
but it will no work at times when I quick push in and back out .
So I add something to check the view of MBProgressHUD.
MBProgressHUD *HUD = [MBProgressHUD HUDForView:bAnimatedView];
if (HUD!= nil) {
[HUD removeFromSuperview];
HUD=nil;
}
I am trying to hide the navigation bar 'back' button during an animation. When the animation completes, the button re-appears.
my code is as follows:
- (void) animateResults {
[self hideNavBarButtons];
[self animatePlayer1];
[self animatePlayer2];
[self performSelector:#selector(showNavBarButtons) withObject:nil afterDelay:3.0];
}
- (void) hideNavBarButtons {
[self.navigationItem setHidesBackButton:YES animated:YES];
}
- (void) showNavBarButtons {
[self.navigationItem setHidesBackButton:NO animated:YES];
}
This works fine on the simulator... but I get weird results on the device. It is very inconsistent, and stops hiding the 'back' button after a few tries. I am assuming I have some delegates messed up.. but I am lost. Any help is appreciated.
Thanks.
i have an action that allows me to present a ModalViewController and show the UITextField as a first responder, the problem is when this ModalViewController will come up it takes a little time, the cause is the keyboard, and when i grab the code to the viewDidAppear the keyboard take a little time to show up, so how can i do to make the UIViewController comes up quickly?
- (IBAction)goToModalViewController
{
ModalSearchViewController *msvc = [[ModalSearchViewController alloc] init];
self.msvc.context = context;
self.msvc.delegate = self;
[self.msvc setModalTransitionStyle:UIModalTransitionStyleCrossDissolve ];
[self presentModalViewController:msvc animated:YES];
}
The viewWillAppear of the ModalViewController:
- (void)viewWillAppear:(BOOL)animated
{
[super viewWillAppear:YES];
[findTextField becomeFirstResponder];
}
Try like this in the viewWillAppear.
- (void)viewWillAppear:(BOOL)animated
{
[super viewWillAppear:animated];
//[findTextField becomeFirstResponder];
[findTextField performSelector:#selector(becomeFirstResponder) withObject:nil afterDelay:0.3];
}
I want to display the view first and then load the data in a background thread. When I navigate from root controller to the view controller, I want to display the view first. As of now, it stays on the root controller until the view controller is loaded. Here's my code for the root controller.
- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath
{
ProductDetailViewController *tempProductDetail = [[ProductDetailViewController alloc] init];
[self.navigationController pushViewController:tempProductDetail animated:YES];
[tempProductDetail release];
}
ProductDetailViewController, here I want to display the view first and then load the data...
- (void)viewWillAppear:(BOOL)animated{
[super viewWillAppear:YES];
[self performSelectorOnMainThread:#selector(workerThread) withObject:nil waitUntilDone:NO];
}
-(void) workerThread{
NSAutoreleasePool *arPool = [[NSAutoreleasePool alloc] init];
[arPool release];
}
Don't know what I'm doing wrong. Please, help.
Use [self performSelectorInBackground:#selector(workerThread) withObject:nil]; instead of
[self performSelectorOnMainThread:#selector(workerThread) withObject:nil waitUntilDone:NO];
found the answer for this issue,
- (void)viewWillAppear:(BOOL)animated{
[super viewWillAppear:YES];
[self performSelectorInBackground:#selector(workerThread) withObject:nil];
}
- (void) workerThread
{
// Set up a pool for the background task.
NSAutoreleasePool* pool = [[NSAutoreleasePool alloc] init];
// only do data fetching here, in my case from a webservice.
//...
// Always update the components back on the main UI thread.
[self performSelectorOnMainThread:#selector(displayView) withObject:nil waitUntilDone:YES];
[pool release];
}
// Called once the background thread task has finished.
- (void) displayView
{
//here in this method load all the UI components
}
Consider using the following pattern instead for threading, in my opinion it's much cleaner:
- (void)viewWillAppear:(BOOL)animated
{
NSInvocationOperation *operation = [[NSInvocationOperation alloc]
initWithTarget:self
selector:#selector(someFunction)
object:nil];
[[NSOperationQueue currentQueue] addObject:operation]; // this will actually start the thread
[operation release];
}
- (void)someFunction
{
// don't need to initialize and release an autorelease pool here,
// you can just write a function as usual ...
[self updateUI];
}
- (void)updateUI
{
if (![NSThread isMainThread]) // if we need a UI update, force it on main thread
{
[self performSelectorOnMainThread:#selector(updateUI) withObject:nil waitUntilDone:YES];
return;
}
// do UI updates here
}
By writing code in this way, you can more dynamically decide which function you want to thread, since there is no autorelease pool requirement. If you need to do UI updates, the updateUI function will make sure for itself that it's running on the main thread, so the caller doesn't need to take this into account.
I'm trying to show a UIImagePickerController as soon as one of my view controller loads. I'd like to this without the user having to press a button so I overrode the viewDidLoad method as follows:
- (void)viewDidLoad {
[super viewDidLoad];
UIImagePickerController *imagePickerController = [[UIImagePickerController alloc] init];
imagePickerController.sourceType = UIImagePickerControllerSourceTypePhotoLibrary;
imagePickerController.allowsImageEditing = YES;
imagePickerController.delegate = self;
[self presentModalViewController:imagePickerController animated:YES];
[imagePickerController release];
}
This compiles and runs, however when the view controller is loaded the image picker is not displayed. This code works fine if I attach it to an event of a button for example. Any ideas?
Thanks.
I had the same problem but solved it. Try using
-(void) awakeFromNib {
}
It will load just after everything else loads.
Try putting the code in
-(void)viewDidAppear
That even runs every time the view appears on the screen though (including when it appears after you dismiss the UIImagePicker), so you might have to add a BOOL value to make it only happen the first time it shows, or when you want it (i.e. not after dismissing a modal view).
It seems that viewDidLoad is too early to use presentModalViewController:animated:. I'd sugget to fork off a one-shot timer to call the method from next run loop iteration:
[NSTimer
scheduledTimerWithTimeInterval:0
target:self
selector:#selector(onLoadTimer:)
userInfo:nil
repeats:NO];
add the following method:
- (void)onLoadTimer:(id)unused
{
[self presentModalViewController:imagePickerController animated:YES];
[imagePickerController release];
}