I have a picker view in my first view controller.
-(void)pickerView:(UIPickerView *)pickerView didSelectRow:(NSInteger)row inComponent(NSInteger)component{
switch(row){
case 1:
isOne = true;
break;
case 2:
isTwo = true;
break;
case 3:
isThree = true;
break;
}
}
I want to read this boolean value in my second view controller. How should I do this?
thanks in advance
finally, I found the answer:
I just have to define a variable string in my first view controller as retain
#property (nonatomic, retain) NSString *aString;
in the implementaion file set:
#synthesize aString;
in the picker view method:
-(void)pickerView:(UIPickerView*)pickerView didSelectRow:(NSInteger)row inComponent:(NSInteger)component {
switch (row) {
case 0:
self.aString = [NSString stringWithString:#"One"];
break;
.....
}
do 1 & 2 in the seconde view controller. and set the selected value from picker view if you switch to the second controller:
SecondViewController * secController = [[SecondViewController alloc] initWithNibName:nil bundle:nil];
secController.modalTransitionStyle = UIModalTransitionStyle;
[secController setAString:self.aString];
[self presentModalViewController:secController animated:YES];
I don't know if this is the best solution but it works for me right now.
Related
I have set up my class with UITabBarDelegate and implemented its method didSelectItem to detect when a certain tabBar item is pressed. Works great. In each tabBar item I have one containerView that can show a "you have to login"-page if the user is not logged in, and another containerView that present viewControllers that are embedded in a navigationController.
I would like to keep track of the viewController that is presented in the current tab item, and/or the root viewController of that tab.
I have tried a number of different approaches, but most of them return nil or I can't get it to work. I think the whole container situation makes it harder to handle.
It looks something like this:
#interface MyTabBarController () <UITabBarDelegate>
- (void)tabBar:(UITabBar *)tabBar didSelectItem:(UITabBarItem *)item {
NSUInteger indexOfTab = [[tabBar items] indexOfObject:item];
switch (indexOfTab) {
case 0: {
NSLog(#"🐳PRESSIIING %lu", (unsigned long)[[tabBar items] indexOfObject:item]);
break;
}
case 1: {
NSLog(#"🐳PRESSIIING %lu", (unsigned long)[[tabBar items] indexOfObject:item]);
break;
}
case 2: {
NSLog(#"🐳PRESSIIING %lu", (unsigned long)[[tabBar items] indexOfObject:item]);
//These return nil
NSLog(#"🐳AAAAAA %#", ((UINavigationController*)_appD.window.rootViewController).visibleViewController);
NSLog(#"🐳AAAAAA %#", ((UITabBarController*)_appD.window.rootViewController).selectedViewController);
NSLog(#"🐳AAAAAA %#", self.navigationController.topViewController);
NSLog(#"🐳AAAAAA %#", self.navigationController.visibleViewController);
//This returns with a value, but can't get it to work with conditionals, that is, when I'm in root, the else is triggered
NSLog(#"🐳AAAAAA %#", self.tabBar.window.rootViewController);
if(!self.tabBar.window.rootViewController) {
NSLog(#"🐳🐳🐳THIS IS NOT ROOT🐳🐳🐳");
}else {
NSLog(#"🐳🐳🐳this is ROOT🐳🐳🐳");
}
// This returns nil
((UINavigationController*)_appD.window.rootViewController).visibleViewController;
((UITabBarController*)_appD.window.rootViewController).selectedViewController;
//Doesn't work
if([self.navigationController.viewControllers[0] isKindOfClass:[ExperiencesListViewController class]]) {
NSLog(#"🐳IS KIND OF CLASS LIST");
}
if([self.navigationController.viewControllers[0].childViewControllers isKindOfClass:[ExperiencesContainerViewController class]]) {
NSLog(#"🐳IS KIND OF CLASS CONTAINER");
}
break;
}
case 3: {
NSLog(#"🐳PRESSIIING %lu", (unsigned long)[[tabBar items] indexOfObject:item]);
break;
}
case 4: {
NSLog(#"🐳PRESSIIING %lu", (unsigned long)[[tabBar items] indexOfObject:item]);
break;
}
default:
break;
}
}
So, what else can I try? Seems like I have to use `self.tabBar.window.rootViewController` in some way, no?
***EDIT***
Oh, and I have tried the `tabBarController` delegate but that doesn't trigger. Also, the `tabBar` is constructed programmatically if that helps.
Sorry to have not read your question correctly. Here's what I suggest you do.
All of these view controllers that you're interested in keeping track of: you should have them send a custom notification from within their -viewDidAppear: (or -viewWillAppear:) method. Then let your ApolloTabBarController object register for that notification. When it gets the notification, you could then store a reference to the view controller. That reference will always point to the active view controller.
In your individual view controllers, do something like the following:
- (void)viewDidAppear:(BOOL)animated
{
[super viewDidAppear:animated];
NSNotificationCenter* nc = [NSNotificationCenter defaultCenter];
[nc postNotificationName:#"XYZViewControllerDidBecomeActiveNotification"
object:self];
}
Of course, you would want to use some kind of constant for the notification name.
In your ApolloTabBarController class, register for XYZViewControllerDidBecomeActiveNotification and implement something like:
- (void)viewControllerDidBecomeActive:(NSNotification *)notification
{
self.activeViewController = [notification object];
}
I hope that helps!
When you're setting up each view controller for each of the tabs, set the tag property of the UITabBarItem to correspond to the index of the view controller in the tab bar's viewControllers array.
UIViewController* myFirstVC = [[UIViewController alloc] init];
UIViewController* mySecondVC = [[UIViewController alloc] init];
// "self" is your ApolloTabBarController.
[self setViewControllers:#[myFirstVC, mySecondVC]];
myFirstVC.tabBarItem =
[[UITabBarItem alloc] initWithTitle:#"First" image:nil tag:0];
mySecondVC.tabBarItem =
[[UITabBarItem alloc] initWithTitle:#"Second" image:nil tag:1];
Then, you'll be able to grab a reference to view controller.
// In your example, your ApolloTabBarController acts as its own delegate.
- (void)tabBar:(UITabBar *)tabBar didSelectItem:(UITabBarItem *)item
{
UIViewController* activeVC =
[[self viewControllers] objectAtIndex:[item tag]];
}
I have made the basic build and it includes a picker. So whatever units of conversion the user selects from the picker, the labels should be updated to show the names of the units for that conversion and once the user enters the number in the text box and hits the button, the answer should be displayed in the second text box. Now the code executes, but the problem is no matter what I pick in the picker, it always does the weight conversion. I know I need a switch statement in there, but I'm not sure how or where I need to implement it.
Another problem is that the labels update, but only when the "Convert" button is pressed, so please help me fix this.
This is my ViewController.h file
#import <UIKit/UIKit.h>
#interface ViewController : UIViewController
<UIPickerViewDelegate, UIPickerViewDataSource> {
IBOutlet UITextField *field1;
IBOutlet UITextField *field2;
IBOutlet UIPickerView *picker;
IBOutlet UILabel *label1;
IBOutlet UILabel *label2;
}
#property (weak, nonatomic) IBOutlet UILabel *textLabelData1;
#property (weak, nonatomic) IBOutlet UILabel *textLabelData2;
#property (nonatomic, retain) UIPickerView *picker;
-(IBAction) currencyConvert:(id)sender;
-(IBAction) weightConvert:(id)sender;
-(IBAction) distanceConvert:(id)sender;
#end
This is my ViewController.m file
#import "ViewController.h"
#interface ViewController ()
#end
#implementation ViewController
#synthesize picker;
static NSString *pd[3] = {#"Currency", #"Weight", #"Speed"};
- (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.
}
#pragma mark UIPickerViewDelegate & UIPickerViewDataSource methods
-(NSInteger)numberOfComponentsInPickerView:(UIPickerView *)pickerView
{
return 1;
}
-(NSInteger)pickerView:(UIPickerView *)pickerView
numberOfRowsInComponent:(NSInteger)component
{
return 3;
}
-(NSString *)pickerView:(UIPickerView *)pickerView titleForRow:
(NSInteger)row forComponent:(NSInteger)component;
{
return pd[row];
}
-(void)pickerView:(UIPickerView *)pickerView didSelectRow:
(NSInteger)row inComponent:(NSInteger)component
{
NSLog(#"didSelectRow %li, inComponent: %li", row, component);
}
-(IBAction)currencyConvert:(id)sender
{
if (pd[0])
{
self.textLabelData1.text = #"Dollar";
self.textLabelData2.text = #"Rupees";
float dollar = [[field1 text] floatValue];
float rupees = dollar * 64.15;
[field2 setText: [NSString stringWithFormat: #"%3.3f", rupees]];
}
/* self.textLabelData1.text = #"Dollar";
self.textLabelData2.text = #"Rupees";
float dollar = [[field1 text] floatValue];
float rupees = dollar * 64.15;
[field2 setText: [NSString stringWithFormat: #"%3.3f", rupees]]; */
}
-(IBAction)weightConvert:(id)sender
{
if (pd[1])
{
self.textLabelData1.text = #"Kilogram";
self.textLabelData2.text = #"Lbs";
float kilogram = [[field1 text] floatValue];
float pounds = kilogram * 2.20462;
[field2 setText: [NSString stringWithFormat: #"%3.3f", pounds]];
}
}
-(IBAction)distanceConvert:(id)sender
{
if (pd[2])
{
self.textLabelData1.text = #"Mile";
self.textLabelData2.text = #"Kilometer";
float miles = [[field1 text] floatValue];
float kilometers = miles * 1.60934;
[field2 setText: [NSString stringWithFormat: #"%3.3f", kilometers]];
}
}
/* Pseudocode for switch statement
-- I tried doing this here, but it gives me an
error saying that "row" is undefined. I understand that
it is a local variable, but how else would I write the
switch statement?
Also, is the placement of the switch statement appropriate here
or will I need to implement it in a function?
switch (row)
{
case 1:
call currencyConvert
case2:
call weightConvert
case3:
call distanceConvert
}
*/
The link to the picture of my Main.storyboard
This isn't the ideal UI and creates inefficiencies, but its your app. I just wanted to point out that you might want to spend time working on its design and structure.
As for a solution to your problem, I cant fix everything for you, but I'll point out some things to make it easier for you.
The reason your labels are not updating is because you are not updating anything until you hit the convert button. The below function is where you'll get the event for the picker's new row
-(void)pickerView:(UIPickerView *)pickerView didSelectRow:
(NSInteger)row inComponent:(NSInteger)component
{
NSLog(#"didSelectRow %li, inComponent: %li", row, component);
}
Try this instead:
-(void)pickerView:(UIPickerView *)pickerView didSelectRow:
(NSInteger)row inComponent:(NSInteger)component
{
NSLog(#"didSelectRow %li, inComponent: %li", row, component);
switch (row) {
case 0:
self.textLabelData1.text = #"Dollar";
self.textLabelData2.text = #"Rupees";
break;
case 1:
// and so on
}
}
Your next issue is that you're not telling your "convert" functions what row is currently selected, and your conditional if does nothing.
In obj-c conditional statements used directly on a variable are basically just checks for initialization. if(x) simply means has x been initialized as a variable = true, if not = false. That's probably not the logic you're looking for in this case.
Next, It appears you're trying to link 3 different functions to the same button press? This is where your above if related issue is causing problems, all three functions are firing at the same time... but only one gets the last say. Presumably the one you linked last, though i cant say for sure. I'd suggest a single function that handles the button press and then relays to the correct methods.
Last, you're never telling the functions anything about the state of the picker. You need to set it as an IBOutlet so your variables will have access to it. Then you can use the picker's selected row function to determine which conversion to use.
The things I highlighted will fix your problems, BUT I would highly recommend checking out some tutorials so you'll learn more about why things do what. I'd recommend: https://www.raywenderlich.com/
Hope that helps!
I have two UIViewControllers, one is a UIPickerViewController, the Other a UITableViewController. Ideally the Picker should get a request from the user to add x amount of some item to the tableView. The Picker gets user inputs and assigns them to variables val1, val2, val3, where val1 is the number of items (number of rows) and val2 is the name or label for the item.
PickerViewController.m
- (IBAction)add:(id)sender
{
TableViewController *tvc = [[TableViewController alloc] init];
[tvc setValues:self.val1 :self.val2 :self.val3];
[self presentViewController:tvc animated:YES completion:nil];
}
TableViewController.m
-(void)setValues:(NSString *)newVal1 :(NSString *)newVal2 :(NSString *)newVal3
{
self.val1 = newVal1;
self.val2 = newVal2;
self.val3 = newVal3;
}
- (void)viewDidLoad
{
[super viewDidLoad];
[self.tableView registerClass:[UITableViewCell class] forCellReuseIdentifier:#"UITableViewCell"];
// This is just a header which holds my "Add" button
UIView *header = self.headerView;
[self.tableView setTableHeaderView:header];
[self addNew:self.val1 :self.val2 :self.val3];
}
- (void)addNew:(NSString *)newVal1 :(NSString *)newVal2 :(NSString *)newVal3
{
if(!self.numberOfRows){
NSLog(#"Initially no of rows = %d", self.numberOfRows);
self.numberOfRows = [self.val1 intValue];
NSLog(#"Then no of rows = %d", self.numberOfRows);
}
else
{
self.numberOfRows = self.numberOfRows + [newVal1 intValue];
NSLog(#"New no rows = %d", self.numberOfRows);
}
NSIndexPath *indexPath = [NSIndexPath indexPathForRow:self.numberOfRows inSection:0];
// Only run when called again .. not initially
if(self.run != 0){
[self.tableView beginUpdates];
[self.tableView insertRowsAtIndexPaths:#[indexPath]withRowAnimation:UITableViewRowAnimationBottom];
self.run ++;
[self.tableView endUpdates];
}
}
// "ADD" button which should go back to the picker and get new items to add to the table
- (IBAction)testAdd:(id)sender
{
PickerViewController *pvc = [[PickerViewController alloc] init];
[self presentViewController:pvc animated:YES completion:nil];
}
Now, I realize every time I call the next view controller I am creating a new instance of it, but I don't know how else to do it, I figure this is the main problem. As of right now, I expect when I leave the tableview for the picker view and return the console should log "New no of rows = x" but that doesn't happen.
I know val3 isn't used and my addNew: may not be the best, but I just need it to handle the basic logging mentioned above and I should be able to take it from there.
Been stuck on this for days
Create a property for TableViewController, and only create it the first time you present it,
- (IBAction)add:(id)sender {
if (! self.tvc) {
self.tvc = [[TableViewController alloc] init];
}
[self.tvc setValues:self.val1 :self.val2 :self.val3];
[self presentViewController:self.tvc animated:YES completion:nil];
}
It's not entirely clear from you question, whether it's this presentation or the one you have in the table view class that you're talking about. It also looks like you're doing something wrong in terms of presentation -- you're presenting the picker view from the table view controller, and also presenting the table view controller from the picker. That's not correct, you should present which ever controller you want to appear second, and that controller should use dismissViewControllerAnimated to go back, not present another controller.
In testAdd you don't need to create a new instance and present it. If you want to go back to the presentingViewController, just use dismissViewControllerAnimated .
And you will go one controller up in the stack.
i have two views MainView and MainInvoicing
from MainView i am sending a int type variable value to MainInvoicing
this is my code
in MainInvoicing.h file i declared int type var
#property (nonatomic, assign) int myChoice;
in MainView.m file on a button click i am calling the MainInvoicing as
MainInvoicing *invoicing = [[MainInvoicing alloc] initWithNibName:#"Invoicing" bundle:nil];
[self presentViewController:invoicing animated:YES completion:nil];
invoicing.myChoice = 1;
from this my MainInvoicing is called perfectly, but myChoice is equal to zero '0'. while it should be '1'
i am receiving this value in MainInvoicing.m as
- (void)viewDidLoad
{
[super viewDidLoad];
[self Start];
}
and the start method is
- (void) Start
{
switch (myChoice)
{
case 1:
NSLog(#"value is %d",myChoice);
break;
case 2:
NSLog(#"value is %d",myChoice);
break;
default:
NSLog(#"Oooopppss...%d",myChoice);
break;
}
}
i am always on default part ….
where am i wrong or any suggestion to get the right value … please help…
You should assign value before you present view controller:
MainInvoicing *invoicing = [[MainInvoicing alloc] initWithNibName:#"Invoicing" bundle:nil];
invoicing.myChoice = 1;
[self presentViewController:invoicing animated:YES completion:nil];
As Greg said in his comment, it's all about order of code. If you look at your code you should see the order in which it is called.
MainInvoicing *invoicing = [[MainInvoicing alloc] initWithNibName:#"Invoicing" bundle:nil];
[self presentViewController:invoicing animated:YES completion:nil];
[self Start];
switch (myChoice)
{
case 1:
NSLog(#"value is %d",myChoice);
break;
case 2:
NSLog(#"value is %d",myChoice);
break;
default:
NSLog(#"Oooopppss...%d",myChoice);
break;
}
invoicing.myChoice = 1;
So you are trying to access the myChoice variable before you set it, which is why you are getting 0 instead of 1.
With all of that said, there is a possibility of your code working as it is written since the viewDidLoad function is not always called serially. But you should not expect it to always work and you should initialize variables before you call code that could use them immediately.
Accept Greg's answer, I was just adding a bit of explanation to the problem.
I have an app where a user can select the default tab they want loaded when they open the app.
I have a settings table view controller that I've created in a storyboard. I have it set to static cells and created a cell that the user can press and uses a push segue to display another tableview with cells that the user can select to select the default tab. On the cell in the main settings table view, I have a label displaying the currently selected tab and the text of that label is set when the view is loaded. The problem I'm having is that when the user goes into the tab selecting table view, selects a tab, then returns to the main settings tableview, the -(void)viewDidLoad method doesn't get called. How can I call that method, or replicate the contents in that method in a new method the is called when the user returns to the main settings tableview?
Here is the code I currently have in my viewDidLoad method:
- (void)viewDidLoad
{
[super viewDidLoad];
NSUserDefaults *theDefaults = [NSUserDefaults standardUserDefaults];
int theInt = [theDefaults integerForKey:#"defTab"];
NSString *theString;
switch (theInt) {
case 0:
theString = #"Home";
break;
case 1:
theString = #"2D";
break;
case 2:
theString = #"3D";
break;
case 3:
theString = #"Calculator";
break;
case 4:
theString = #"Extras";
break;
default:
break;
}
currentTabLabel.text = theString;
}
Thanks in advance.
use:
-(void)viewDidAppear:(BOOL)animated {
[self.tableView reloadData];
}
use.
-(void)viewWillAppear:(BOOL)animated {
[self.tableView reloadData];
}