I have a little problem, because I can't pass data to another view controller.
-(void)barcodeData:(NSString *)barcode type:(int)type
{
mainTabBarController.selectedViewController=self;
[status setString:#""];
[status appendFormat:#"Type: %d\n",type];
[status appendFormat:#"Type text: %#\n",[dtdev barcodeType2Text:type]];
[status appendFormat:#"Barcode: %#",barcode];
[displayText setText:status];
codede1String = barcode;
NSLog(#"%#",codede1String);
[self updateBattery];
}
In the code above I put a barcode in the String codeString1. So far no problem, but when I send this data to the other viewController barCodeString suddenly is NULL.
I pass data to viewcontroller like this:
-(void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender{
if ([segue.identifier isEqualToString:#"barcode"]) {
main =[ segue destinationViewController];
main.code1.text = codede1String;
}
}
So how do I solve this problem?
I assume that code1 is a text field, text view or label. If so, the reason this doesn't work, is that the outlets for main are not yet set at the time of prepareForSegue. You need to create a string property in main and set its value to code1String in prepareForSegue. Then, in main's viewDidLoad or viewDidAppear, set code1's text value to that string.
Note that IBOutlets of the destination view controller are not set yet in prepareForSegue. So if main.code1 represents a UILabel, it will be nil because the view is not yet loaded. You should pass the string directly using a setter method: [main setCodeString:codede1String] and then configure the user interface in viewDidLoad: self.code1.text = [self codeString].
Do this in the viewDidLoad of the view controller, then it works fine
- (void)viewDidLoad
{
codedeString=[[NSString alloc] init];
}
Try doing this, it helped me once for the same kinda issue (but with xibs)
Add one more line, just before any assignments
[main.view setAlpha:1.0f];
main.code1.text = codede1String;
Hope this will help you as well.
Related
I have an app in which I am loading variable view controllers depending on where the user is in the app. This is my code.
-(IBAction)buttonPressed:(id)sender;{
if (mission <1) {
gameViewController *detailViewController = [[gameViewController alloc] initWithNibName:#"gameViewController" bundle:nil];
[self.navigationController pushViewController:detailViewController animated:YES];
detailViewController.which2 = which;
}
else if (mission > 0) {
NSString *viewController = #"gameViewController";
NSString *missionViewController = [viewController stringByAppendingString:missionNo];
Class controllerClass = NSClassFromString (missionViewController);
id detailViewController = [[controllerClass alloc] initWithNibName:#"gameViewController" bundle:nil];
NSLog(#"missionViewController;%#",missionViewController);
[self.navigationController pushViewController:detailViewController animated:YES];
detailViewController .which2 = which;
}
}
everything work great except I want to pass a string from the first view controller to the second view controller which ever one that may be.
As you can see I have put in the code just above detailViewController.which2 = which;
I have created the property and synthesized NSString *which in my first view controller and NSString *which2 in all the subsequent view controllers. in the first instance where mission is <1 everything works ok and NSLog shows the string being passed. However with the second detailViewController (which is the variable view controller) I get the error Property 'which2' not found on object of type"_strong id' Does anyone have any suggestion on how to resolve this?
the other viewControllers are gameViewController1, gameViewController2, etc. Each is rather long and complex. But they all load into the same xib file gameViewController. There is a UIlabel that update to one higher once the user finishes that gameView so they can go on the the next on in the series or go back to the main menu. If they go back to the main menu the number is added to "gameViewController" so the correct one is loaded. So I can't specify which view controller is going to load since it depends on the user's place. Thus the missionViewController with the # of mission added to load the correct view controller. Each of the subsequent view controllers has a which2 created and synthesized. What if we pretend that all subsequent view controllers just had a UILabel that is going to display the string "which2 in it. All I want to do is pass the string "which" to the next viewController (whichever one that is) as "which2".
Dynamic binding allows you to send messages to an id as long as the selector exists in the project, but dot-syntax is not allowed.
Changing
detailViewController.which2 = which;
to
[detailViewController setWhich2:which];
should suppress the warning.
write this : `detailViewController .which2 = which;
just before you push navigation controller.`
UPDATE:
Use Protools to update the value.
#protocol MissionProtocol
#required
-(void) updateValue:(NSSTring*) value;
#end
Implement the protocols in your ViewControllers. i.e.
#interface MissionViewController:UIViewController<MissionProtocol>
....
#end
In your implementation file, implement the method updateValue.
-(void) updateValue:(NSString*) value
{
self.which2=value;
}
Then change your original code to:
NSString *viewController = #"gameViewController";
NSString *missionViewController = [viewController stringByAppendingString:missionNo];
Class controllerClass = NSClassFromString (missionViewController);
id<MissionProtocol> detailViewController = [[controllerClass alloc] initWithNibName:#"gameViewController" bundle:nil];
[detailViewController updateValue:which];
I am trying to grab the string off an object in a table row when it is clicked. I have seen tutorials about getting the string and passing it to synthesized label however I am unable to pass the same string to a synthesized string in my modal view. Is this possible? My code in the parent view is as follows.
- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath
{
Modules *selectedModule;
selectedModule = [fixedArray objectAtIndex:indexPath.row];
NSString *moduleComponent = [selectedModule valueForKey:#"name"];
DetailViewController *detail = [self.storyboard instantiateViewControllerWithIdentifier:#"Detail"];
[self.navigationController pushViewController:detail animated: YES];
detail.number.text = moduleComponent;
detail.moduleLabel.text = moduleComponent;
detail.module = moduleComponent;
}
The detail.moduleLabel.text displays correctly however when I try to alert or draw a label using the detail.module I receive null. Any help is greatly appreciated.
Move [self.navigationController pushViewController:detail animated: YES]; after assigning the value to the detail controller.
EDIT:
Another point to note is when exactly do you try to alert it - viewDidLoad, viewWillAppear, viewDidAppear. Try in the different methods to see what the result is. I apologize but I am unable to test it now and give you the result itself, but have experienced similar behavior (not assigned value) depending on the specific event (viewDidLoad, viewWillAppear, viewDidAppear) where I try to access the value.
I have this in one view:
-(void)viewWillDisappear:(BOOL)animated
{
RootViewController *rVC = [[RootViewController alloc] initWithNibName:#"RootViewController" bundle:nil];
[rVC setMessage:[label text]];
NSLog(#"ihere - %#",rVC.message);
}
The NSLog returns the correct string. How would I reload the data in the RootViewController to update the string message there?
doing this doesn't work in my RootViewController (which i go back to in navcontroller):
-(void)viewWillAppear
{ [[self message] reloadData]; }
because the message is just a string. Can somebody show me how to fix this please?
Hi can someone else try to help me please?
In the viewWillAppear event, i need to reloadData on a NSString. So i need to convert it somehow to an object before i can use reloadData on it.
That's because NSString doesn't have a reloadData method.
And as it is immutable it wouldn't make sense if it did.
What you probably want to do is display your string in viewWillAppear and change the model property in the controller where it gets this from.
Delegation is the usual way to do this and I've written a couple of examples that might help you see what is happening;
DelegationExample
TableViewDelegation
Presuming you're using a NavigationController: Consult your navigation controller's stack (property navigationController in your current controller) to access the element for your root view controller (this would generally be the zeroth element -- use viewControllers). Set your message property using that pointer. Then be sure that your root view controller, in viewWillAppear, uses the property you just set to reset the text of the label of interest (using a simple assignment statement -- self.myLabel.text = self.message;.
Hi to all,
I passed a variable from first.m to seViewController.m. I'm able to print that variable using NSLog(#variable) but I'm unable to use textField.text=variable. How to print that variable in a textbox?
First.m
-(void)buttonPressed01
{
seViewController *seView = [[seViewController alloc] init];
[seView insert:myString];
[self.navigationController popViewControllerAnimated:YES];
}
seviewcontroller.m
-(void)insert:(NSString*) myString
{
NSLog(#"%#",myString);
textField.text=[NSString stringWithFormat:#"%#",myString];
}
seViewController *seView = [[[seViewController alloc] initWithNibName:#"seViewController" bundle:nil] autorelease];
[seView insert:String];
[[self navigationController] pushViewController:seView animated:YES];
seviewcontroller.m
-(void)insert:(NSString*) myString
{
NSLog(#"%#",myString);
textField.text=myString;
}
Until your seViewController is loaded you can not use its outlets, here you are using textField. It won't set text because after seViewController *seView = [[seViewController alloc] init]; the view is initialized but still you need to load its view in memory in order to use its outlet. so if you are using its view then after addingSubview, or presenting modalView or, pushing it on navigation stack call that method.
or else you should have a string in seviewcontroller which you will set and when controller's will be loaded in memory viewDidLoad just do what you are doing right now in insert method, set TextField's text.
Also, I am not sure what you want to do with seView? why you are creating new instance and not using it ? May be you have created this controller earlier and you want to change that controller's textField text not the new one. Then in that case you should refer that controller not this one because its totally different object.
Thanks
When you pop from stack it loads the instance of the view controller you pushed in to stack. Here you created a new instance and set the text field and loads the instance in the stack. Thats why text field does not show the value to set. If you want to pass the value to the class you nee to pass the value using some singleton class or app delegate.
I think its not working because you are passing this variable to a new instance of your seViewController while you are popping it in the next line. You have to get the same instance as -
seViewController *seView = (seViewController*)[self parentViewController];
[seView insert:myString];
[self.navigationController popViewControllerAnimated:YES];
You can use this one if what I understood is correct,
you can retrieve the array of viewControllers from the navigation controller.
You dont need to initialize the view controller and this wont work as explained above.
I am creating a delegate view controller and presenting it to the user to perform an action but I would like to change a NSString on the delegate view controller based on the originating view controller. For example if the delegate view controller is a delegate of viewControllerA, then display Foo, but if its a delegate of viewControllerB then display Blah. ALthough I cant figure out how to pass some sort of information that indicates what the originating view controller is. I noticed that if i do an NSLog(#"I'm from %#",[self delegate]); it will tell me what the originating view controller is, as well as the memory address, but I cant seem to translate that into an NSString object to examine its value. If theres a way to make that work, or a better way to do this then that works too...
- (IBAction)editDate {
DatePickerViewController *datePickerView = [[DatePickerViewController alloc] init];
datePickerView.delegate = self;
datePickerView.modalTransitionStyle = UIModalTransitionStyleFlipHorizontal;
[self presentModalViewController:datePickerView animated:YES];
[datePickerView release];
}
It seems like you're using some terminology in ways that are different from what most Objective-C coders would mean.
Here you're instantiating a view controller to show as a modal view. That view controller has a property called delegate that allows it to call some methods to report changes to its state. That doesn't make it a "delegate view controller", that makes it "an object with a delegate".
You happen to be using another view controller class as the delegate, but any object that implements the methods that DatePickerViewController objects want to call to report changes could be assigned to that delegate property.
I think that the question you're asking is "how do I make the DatePickerViewController display different information depending on what kind of object it's reporting to?", and the answer is much the same as "how do I make a UILabel show different text depending on the view controller that created it?"—you set properties or call methods on in when you create it.
If you really just want to pass a string to DatePickerViewController, you could add an NSString* property to DatePickerViewController and set it with arbitrary text, with
datePickerView.myString = #"some information that you want";
You could use the class of the delegate.
if([[self delegate] isKindOfClass:[ViewControllerA class]]) {
[self doViewControllerAThings];
}
else {
...
}