I want to set the delegate of tableview to another custom class in a UITableViewController,
It's ok with objectC,but get an error with Swift,detail as following images.
old objectC code is here:https://github.com/ninjinkun/NJKScrollFullScreen
1、OK in ObjectC:
#import "ViewController.h"
#import "UIViewController+NJKFullScreenSupport.h"
#interface ViewController ()
#property (nonatomic) NSArray *data;
#property (nonatomic) NJKScrollFullScreen *scrollProxy;
#end
#implementation ViewController
- (void)viewDidLoad
{
[super viewDidLoad];
_scrollProxy = [[NJKScrollFullScreen alloc] initWithForwardTarget:self]; // UIScrollViewDelegate and UITableViewDelegate methods proxy to ViewController
self.tableView.delegate = (id)_scrollProxy; // cast for surpress incompatible warnings
_scrollProxy.delegate = self;
}
....
#end
2、Error in Swift，I think maybe it's type convert problem:
error: see error
class GLBaseTableViewController : UITableViewController,NJKScrollFullscreenDelegate{
var dataSource = []
var scrollProxy:NJKScrollFullScreen!
override func viewDidLoad() {
super.viewDidLoad()
scrollProxy = NJKScrollFullScreen(forwardTarget: self)
self.tableView.delegate = scrollProxy
scrollProxy.delegate = self
}
3、Delegate ob：
#protocol NJKScrollFullscreenDelegate;
#interface NJKScrollFullScreen : NSObject<UIScrollViewDelegate>
#property (nonatomic, weak) id<NJKScrollFullscreenDelegate> delegate;
Related
I have two text views beside each other with multiple lines of text.
How can I make them both scroll together based on scrolling either one of them at the same time?
First
#interface ViewController : UIViewController <UITextViewDelegate>
second make both textViews delagates
tv1.delegate = self
tv2.delegate = self
Implement
-(void)scrollViewDidScroll:(UIScrollView *)inScrollView {
self.tv1.contentOffset = inScrollView.contentOffset;
self.tv2.contentOffset = inScrollView.contentOffset;
}
Here is a demo txView
Edit
.h
#import <UIKit/UIKit.h>
#interface ViewController : UIViewController <UITextViewDelegate>
#property (weak, nonatomic) IBOutlet UITextView *tv1;
#property (weak, nonatomic) IBOutlet UITextView *tv2;
#end
.m
#import "ViewController.h"
#interface ViewController ()
#end
#implementation ViewController
- (void)viewDidLoad {
[super viewDidLoad];
// Do any additional setup after loading the view, typically from a nib.
self.tv1.delegate = self;
self.tv2.delegate = self;
}
- (void)scrollViewDidScroll:(UIScrollView *)inScrollView {
self.tv1.contentOffset = inScrollView.contentOffset;
self.tv2.contentOffset = inScrollView.contentOffset;
}
I need to pass a string from a NSObject class to a UIViewController, I understand that the best way is delegation but the delegate method isn't being called. I'm trying to set the UILabel an DieFacesViewController as the selectedOption from TemporarySelection.
A tableview shows the value of CustomOptionStore, once it's tapped passes its value to TemporarySelection and opens the modal view DieFacesViewCountroller which should, at least in my mind, take the label value from TemporarySelection. The reason I created TemporarySelection is because the DieFacesViewController will be used by other classes, not only by CustomOptionStore, and it will need to load the label from all those classes when different tableViews are selected.
I tried to set the delegate as self in both viewDidLoad and viewWillAppear with no luck, I don't understand if the view loads before being able to call the delegate method or if there's something wrong the way I set the method up.
I've been stuck here for two days, this is the first time I post a question so please forgive me if it's a bit confused.
my delegator class TemporarySelection.h is
#import <Foundation/Foundation.h>
#import "CustomOptionsStore.h"
#class DieFacesViewController;
#protocol TemporarySelectionDelegate <NSObject>
-(void)sendSelection;
#end
#interface TemporarySelection : NSObject
#property (nonatomic, weak) id <TemporarySelectionDelegate> delegate;
#property (nonatomic, strong) NSString *selectedOption;
-(void)addSelection: (CustomOptionsStore *) selection;
#end
and my TemporarySelection.m is
#import "TemporarySelection.h"
#implementation TemporarySelection
-(void)addSelection: (CustomOptionsStore *) selection{
self.selectedOption = selection.description;
[self.delegate sendSelection];
}
#end
the delegate class DiewFacesViewController.h is
#import <UIKit/UIKit.h>
#import "SelectedStore.h"
#import "TemporarySelection.h"
#interface DieFacesViewController : UIViewController <TemporarySelectionDelegate>
#property (strong, nonatomic) IBOutlet UILabel *SelectionName;
#end
and the DieFacesViewController.m is
#import "DieFacesViewController.h"
#interface DieFacesViewController ()
#end
#implementation DieFacesViewController
- (void)viewDidLoad {
TemporarySelection *ts = [[TemporarySelection alloc]init];
ts.delegate = self;
[super viewDidLoad];
}
-(void)sendSelection{
TemporarySelection *ts = [[TemporarySelection alloc]init];
self.SelectionName.text = ts.selectedOption;
}
-(void)viewWillAppear:(BOOL)animated {
[super viewWillAppear:YES];
}
You are not setting the delegate object properly.Check the above code
#import "DieFacesViewController.h"
#interface DieFacesViewController ()<TemporarySelectionDelegate>
{
//global object
TemporarySelection *ts;
}
#end
#implementation DieFacesViewController
- (void)viewDidLoad {
ts = [[TemporarySelection alloc]init];
ts.delegate = self;
[super viewDidLoad];
}
-(void)sendSelection{
//Use the object to extract
self.SelectionName.text = ts.selectedOption;
}
-(void)viewWillAppear:(BOOL)animated {
[super viewWillAppear:YES];
}
I have four classes MainVC, ParentClient and ChildClient1, ChildClient2(which are subclasses of ParentClient). ParentClient has a delegate to MainVC such that in MainVC
- (void)viewDidLoad
{
[super viewDidLoad];
[ParentClient instance].mainViewDelegate = self;
}
And then the ParentClient looks like this
#interface BaseClient : NSObject
#property (assign) id<MainVCInteraction> mainViewDelegate;
+(instancetype) instance;
#end
Now I want to access mainViewDelegate from ChildClient1, ChildClient2 and it returns me nil while [ParentClient instance].mainViewDelegate returns the correct value
Here is what I did I removed the BaseClient Class so that ChildClient1, ChildClient2 were no longer subclasses of BaseClient. I defined a objective-c protocol file MainVCInteaction.h and made Client1, Client2 look like this:
#import "MainVCInteraction.h"
#interface ChildClient1 : NSObject
#property (assign) id<MainVCInteraction> mainViewDelegate;
+(instancetype) instance;
#end
#import "MainVCInteraction.h"
#interface ChildClient2 : NSObject
#property (assign) id<MainVCInteraction> mainViewDelegate;
+(instancetype) instance;
#end
And then MainVC implements this protocol, I assigned the delegate like this
- (void)viewDidLoad
{
[super viewDidLoad];
[ChildClient1 instance].mainViewDelegate = self;
[ChildClient2 instance].mainViewDelegate = self;
}
I'm trying to separate the UITextViewDelegate methods from the main class of my project, I created a class to manage the delegate methods, but I can not change the values of the IBOulets from the main class.
I made a test project with a ViewController and a TextFieldController, in the Storyboard I add a text field and a label. What I want to do is change the text of the label when I start to write in the text field. Here is the code:
ViewController.h:
#import <UIKit/UIKit.h>
#import "TextFieldController.h"
#interface ViewController : UIViewController
#property (strong, nonatomic) IBOutlet UITextField *textField;
#property (strong, nonatomic) IBOutlet UILabel *charactersLabel;
#end
ViewController.m:
#import "ViewController.h"
#interface ViewController ()
#property (nonatomic, strong) TextFieldController *textFieldController;
#end
#implementation ViewController
- (void)viewDidLoad
{
[super viewDidLoad];
_textFieldController = [[TextFieldController alloc] init];
_textField.delegate = _textFieldController;
}
- (void)didReceiveMemoryWarning
{
[super didReceiveMemoryWarning];
}
#end
TextFieldController.h:
#import <UIKit/UIKit.h>
#import "ViewController.h"
#interface TextFieldController : UIViewController <UITextFieldDelegate>
#end
Text Field Controller.m:
#import "TextFieldController.h"
#interface TextFieldController ()
#property ViewController *viewController;
#end
#implementation TextFieldController
- (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil
{
self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil];
if (self) {
// Custom initialization
}
return self;
}
- (void)viewDidLoad
{
[super viewDidLoad];
// Do any additional setup after loading the view.
}
- (void)didReceiveMemoryWarning
{
[super didReceiveMemoryWarning];
// Dispose of any resources that can be recreated.
}
- (BOOL) textFieldShouldBeginEditing:(UITextField *)textField {
NSLog(#"hello");
_viewController.charactersLabel.text = #"hello";
return YES;
}
#end
When I start writing in the text field the message "Hello" is printed in the log, but the text of the label does not change. I want to know how to change the label text value from the other class.
First change the TextFieldController.h like this:
#import <UIKit/UIKit.h>
#import "ViewController.h"
#interface TextFieldController : NSObject <UITextFieldDelegate>
{
}
#property (nonatomic, assign) ViewController *viewController;
#end
Then change your TextFieldController.m file like this:
#import "TextFieldController.h"
#interface TextFieldController ()
#end
#implementation TextFieldController
- (BOOL) textFieldShouldBeginEditing:(UITextField *)textField {
NSLog(#"hello");
self.viewController.charactersLabel.text = #"hello";
return YES;
}
#end
In the ViewController.m do like that:
#import "ViewController.h"
#interface ViewController ()
#property (nonatomic, strong) TextFieldController *textFieldController;
#end
#implementation ViewController
- (void)viewDidLoad
{
[super viewDidLoad];
_textFieldController = [[TextFieldController alloc] init];
_textFieldController.viewController = self;
_textField.delegate = _textFieldController;
}
- (void)didReceiveMemoryWarning
{
[super didReceiveMemoryWarning];
}
#end
This will work but I personally dont like that way you took.
Good luck :)
It's failing because _viewController is nil. You need to assign the viewController property in your delegate in order to support the two way communication.
Also, I'd strongly recommend you make your delegate object a subclass of NSObject, and not UIViewController. It does nothing with controlling views. You can just manually instantiate it in your ViewController objects viewDidLoad.
In TextViewController I don't see where the viewController property (_viewController ivar) is being set so it is probably nil. You should set it when you create the TextViewController instance.
When you are navigating to other controllers using storyboad's segue then you need to implement prepareForSegue method to initialised its properties as follows
-(void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender
{
if([segue.identifier isEqualToString:#"segue for textFieldController"])
{
TextFieldController *_textFieldController = [segue destinationViewController];
_textField.delegate = _textFieldController;
}
}
But I was wondering, why are you setting textFieldDelegate here, why can't you set in TextFieldController's viewDidLoad method as then you didn't you to implement above prepareForSegue method call?
Besides you are keeping strong reference of each other and you are creating strong retain cycle.
One more thing, following code
_textField.delegate = _textFieldController;
will not work, until textFieldController is loaded and its viewDidLoad method is being called as you are only initialising it but its outlets will not be connected until view is loaded into navigation stack.
I was using MapView on Xcode, and everything was working fine, but when I added the following line
mapView.delegate = self;
to ViewController.m, I get the error
Assigning to 'id<MKMapViewDelegate>' from incompatible type 'ViewController *const
__strong'
Here is my code:
ViewController.m:
#import "ViewController.h"
#interface ViewController ()
#end
#implementation ViewController
#synthesize mapView;
- (void)viewDidLoad
{
[super viewDidLoad];
mapView.showsUserLocation = YES;
mapView.delegate = self; //The line I added that creates the error
// Do any additional setup after loading the view, typically from a nib.
}
#end
ViewController.h
#import <UIKit/UIKit.h>
#import <MapKit/MapKit.h>
#interface ViewController : UIViewController {
MKMapView *mapview;
}
#property (weak, nonatomic) IBOutlet MKMapView *mapView;
#end
You need to declare that your class implements the MKMapViewDelegate methods. In your ViewController.h header file, change the line
#interface ViewController : UIViewController {
to
#interface ViewController : UIViewController <MKMapViewDelegate> {
You need to declare that you respond to MKMapViewDelegate calls.
To do this, simply update the header file for the corresponding class (ViewController.h in your example) as follows:
#interface ViewController : UIViewController <MKMapViewDelegate> {