hide/unhide textfield by clicking bar button item in navigation - ios

Question

I have one viewcontroller. At top i am having one textfield.And also i am having one bar button item(add button) at navigation bar. In viewdidload initially my texfield will be hidden. when user press that bar button (add button) my textfield should be visible. now its working well.
Needer:
when user pressed (first time) my bar button (add button) should visible. then again when user press that same bar button item (add button) its should be again hidden.i did in visible .but i don't know again how to make its hidden...i am very beginner please help me out
i know that its should be done in if statement.but i don't know what condition should use ...help me this
Thanks in advance !
#import "ViewController.h"
#interface ViewController () {
UIBarButtonItem *addButton;
}
#end
#implementation ViewController
#synthesize tableView;
#synthesize textField;
- (void)viewDidLoad {
[super viewDidLoad];
addButton = [[UIBarButtonItem alloc] initWithBarButtonSystemItem:UIBarButtonSystemItemAdd target:self action:#selector(addButtonPressed:)];
self.navigationItem.rightBarButtonItem = addButton;
txtField.hidden = YES;
}
- (void)addButtonPressed:(id)sender
{
txtField.hidden = NO;
}
#end

Answer 1

Ok for that you have to define a Bool variable, change the status of that Boolean variable on the click of your button like this
#import "ViewController.h"
#interface ViewController () {
Bool isShowingTF;
UIBarButtonItem *addButton;
}
#end
#implementation ViewController
#synthesize tableView;
#synthesize textField;
- (void)viewDidLoad {
[super viewDidLoad];
isShowingTF = NO;
addButton = [[UIBarButtonItem alloc] initWithBarButtonSystemItem:UIBarButtonSystemItemAdd target:self action:#selector(addButtonPressed:)];
self.navigationItem.rightBarButtonItem = addButton;
txtField.hidden = YES;
}
- (void)addButtonPressed:(id)sender
{
if (isShowingTF) {
txtField.hidden = YES;
} else {
txtField.hidden = NO;
}
isShowingTF = ! isShowingTF;
}
#end

Answer 2

you can do this in many ways just like set BOOL for yes:No condition, else identify with Tags else use some common NSString like
#interface ViewController () {
UIBarButtonItem *addButton;
NSString *GettouchStr;
}
- (void)viewDidLoad {
[super viewDidLoad];
addButton = [[UIBarButtonItem alloc] initWithBarButtonSystemItem:UIBarButtonSystemItemAdd target:self action:#selector(addButtonPressed:)];
self.navigationItem.rightBarButtonItem = addButton;
txtField.hidden = YES;
GettouchStr=#"hidden";
}
- (void)addButtonPressed:(id)sender
{
if ([GettouchStr isEqualToString:#"hidden"])
{
[UIView animateWithDuration:0.3 animations:^{
txtField.alpha = 1;
} completion: ^(BOOL finished) {
txtField.hidden = NO;
GettouchStr=#"UNhidden";
}];
}
else
{
[UIView animateWithDuration:0.3 animations:^{
txtField.alpha = 0;
} completion: ^(BOOL finished) {
txtField.hidden = YES;
GettouchStr=#"hidden";
}];
}
}
Choice - 2 for additional animation
- (void)addButtonPressed:(id)sender
{
if ([GettouchStr isEqualToString:#"hidden"])
{
txtField.alpha = 1;
[UIView animateWithDuration:2.f delay:0.f options:UIViewAnimationOptionCurveEaseIn animations:^{
txtField.alpha = 0;
} completion:^(BOOL finished) {
[UIView animateWithDuration:2.f delay:0.f options:UIViewAnimationOptionCurveEaseInOut animations:^{
txtField.alpha = 1;
txtField.hidden = NO;
GettouchStr=#"UNhidden";
} completion:nil];
}];
}
else
{
txtField.alpha = 0;
[UIView animateWithDuration:2.f delay:0.f options:UIViewAnimationOptionCurveEaseIn animations:^{
txtField.alpha = 1;
} completion:^(BOOL finished) {
[UIView animateWithDuration:2.f delay:0.f options:UIViewAnimationOptionCurveEaseInOut animations:^{
txtField.alpha = 0;
txtField.hidden = YES;
GettouchStr=#"hidden";
} completion:nil];
}];
}
}
Choice-3
see this link may be help with you

Answer 3

In Swift 4, If you have only one bar button item in the right side you can use this one,
self.navigationItem.rightBarButtonItem = nil; //To Hide
self.navigationItem.rightBarButtonItem = barButtonItem //To show
Suppose if you have multiple bar button in the right side, for example suppose you have two bar button items(search button and filter button) in the right side of your navigation item. And now you have to hide only search button, you can use like,
self.navigationItem.rightBarButtonItems = [filterItem]
Now what happening is, you can completely hide the search button from the navigation item and the filter item comes in the place of search item
Then if you want to show the hided bar button,
self.navigationItem.rightBarButtonItems = [searchItem, filterItem]
Now in the navigationItem searchItem comes as the first item, filterItem comes as the second item.