iOS
मल्टीकास्ट डेलिगेट्स

परिचय

मल्टीकास्ट किसी भी नियंत्रण के लिए प्रतिनिधियों

अग्रेषित संदेशों को एक वस्तु दूसरे को प्रतिनिधियों द्वारा, इन संदेशों को कई पर्यवेक्षकों को मल्टीकास्टिंग करते हुए ।।

चरण 1: - RRMulticastDelegate का NSObject क्लास बनाएं

चरण 2: - RRMulticastDelegate.h फ़ाइल में कोड लागू करें

#import <Foundation/Foundation.h>

@interface RRMulticastDelegate : NSObject

{
    //Handle multiple observers of delegate
    NSMutableArray* _delegates;
}

// Delegate method implementation to the list of observers
- (void)addDelegate:(id)delegate;
- (void)removeDelegate:(id)delegate;

// Get multiple delegates
-(NSArray *)delegatesObjects;

@end

चरण 3: - RRMulticastDelegate.m फाइल में निम्नलिखित कोड लागू RRMulticastDelegate.m हैं

#import "RRMulticastDelegate.h"

@implementation RRMulticastDelegate

- (id)init
{
    if (self = [super init])
    {
        _delegates = [NSMutableArray array];
    }
    return self;
}

-(NSArray *)delegatesObjects
{
    return _delegates;
}

- (void)removeDelegate:(id)delegate
{
    if ([_delegates containsObject:delegate])
        [_delegates removeObject:delegate];
}

- (void)addDelegate:(id)delegate
{
    if (![_delegates containsObject:delegate])
        [_delegates addObject:delegate];
}

- (BOOL)respondsToSelector:(SEL)aSelector
{
    if ([super respondsToSelector:aSelector])
        return YES;
    
    // if any of the delegates respond to this selector, return YES
    for(id delegate in _delegates)
    {
        if (!delegate)
            continue;
        
        if ([delegate respondsToSelector:aSelector])
        {
            return YES;
        }
    }
    return NO;
}

- (NSMethodSignature *)methodSignatureForSelector:(SEL)aSelector
{
    // can this class create the sinature?
    NSMethodSignature* signature = [super methodSignatureForSelector:aSelector];
    
    // if not, try our delegates
    if (!signature)
    {
        for(id delegate in _delegates)
        {
            if (!delegate)
                continue;
            
            if ([delegate respondsToSelector:aSelector])
            {
                return [delegate methodSignatureForSelector:aSelector];
            }
        }
    }
    return signature;
}

- (void)forwardInvocation:(NSInvocation *)anInvocation
{
    // forward the invocation to every delegate
    for(id delegate in _delegates)
    {
        if (!delegate)
            continue;
        
        if ([delegate respondsToSelector:[anInvocation selector]])
        {
            [anInvocation invokeWithTarget:delegate];
        }
    }
}

@end

चरण 4: - RRProperty का NSObject श्रेणी वर्ग बनाएं

चरण 5: - NSObject+RRProperty.h फ़ाइल में निम्नलिखित कोड लागू करें

#import <Foundation/Foundation.h>

#import "RRMulticastDelegate.h"

@interface NSObject (RRProperty)<UITextFieldDelegate,UITableViewDataSource>

-(void)setObject:(id)block forKey:(NSString *)key;
-(id)objectForKey:(NSString *)key;

#pragma mark - Multicast Delegate

- (RRMulticastDelegate *)multicastDelegate;
- (RRMulticastDelegate *)multicastDatasource;

-(void)addDelegate:(id)delegate;
-(void)addDataSource:(id)datasource;

@end

चरण 6: - NSObject+RRProperty.m फ़ाइल में कोड लागू करने के बाद

#import "NSObject+RRProperty.h"

#import <objc/message.h>
#import <objc/runtime.h>

#pragma GCC diagnostic ignored "-Wprotocol"

static NSString *const MULTICASTDELEGATE = @"MULTICASTDELEGATE";
static NSString *const MULTICASTDATASOURCE = @"MULTICASTDATASOURCE";

@implementation NSObject (RRProperty)

-(void)setObject:(id)block forKey:(NSString *)key
{
    objc_setAssociatedObject(self, (__bridge const void *)(key), block, OBJC_ASSOCIATION_RETAIN);
}

-(id)objectForKey:(NSString *)key
{
    return objc_getAssociatedObject(self, (__bridge const void *)(key));
}

#pragma mark - Multicast Delegate

- (RRMulticastDelegate *)multicastDelegate
{
    id multicastDelegate = [self objectForKey:MULTICASTDELEGATE];
    if (multicastDelegate == nil) {
        multicastDelegate = [[RRMulticastDelegate alloc] init];
        
        [self setObject:multicastDelegate forKey:MULTICASTDELEGATE];
    }
    
    return multicastDelegate;
}

- (RRMulticastDelegate *)multicastDatasource
{
    id multicastDatasource = [self objectForKey:MULTICASTDATASOURCE];
    if (multicastDatasource == nil) {
        multicastDatasource = [[RRMulticastDelegate alloc] init];
        
        [self setObject:multicastDatasource forKey:MULTICASTDATASOURCE];
    }
    
    return multicastDatasource;
}

-(void)addDelegate:(id)delegate
{
    [self.multicastDelegate addDelegate:delegate];
    
    UITextField *text = (UITextField *) self;
    text.delegate = self.multicastDelegate;
}

-(void)addDataSource:(id)datasource
{
    [self.multicastDatasource addDelegate:datasource];
    UITableView *text = (UITableView *) self;
    text.dataSource = self.multicastDatasource;
}

@end

अंत में आप किसी भी नियंत्रण के लिए मल्टीकास्ट डेलगेट का उपयोग करते हैं ...

पूर्व के लिए ...

NSObject+RRProperty.h फ़ाइल में अपने NSObject+RRProperty.h वर्ग को आयात करें ताकि मल्टीकास्ट डेलीगेट या डेटासोर्स सेट करने के लिए उसके तरीकों का उपयोग किया जा सके।

UITextView *txtView = [[UITextView alloc]initWithFrame:txtframe];
[txtView addDelegate:self];
    
UITableView *tblView = [[UITableView alloc]initWithFrame:tblframe];
[tblView addDelegate:self];
[tblView addDataSource:self];