ios - 从联系人选择器中创建单例

Question

我开始使用我的应用程序中的方法创建单例，这些方法需要被不同的 viewController 重用。

我这里有一个方法可以访问用户的联系人，并允许他们通过 SMS 发送消息。这工作得很好，我现在想把代码变成一个可以被其他 viewController 访问的单例。

到目前为止，这是我的代码。我不确定如何开始。任何建议将不胜感激!

发送短信.h

#import <UIKit/UIKit.h>
#import "SMContactsSelector.h"
#import <MessageUI/MessageUI.h>

@interface SendSMS : UIViewController

- (IBAction)button:(id)sender;

@end

发送短信.m

#import "SendSMS.h"

@interface SendSMS ()

@end

@implementation SendSMS

NSMutableArray *phoneArray;

- (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)viewDidAppear:(BOOL)animated {

    NSString *phoneString = [[NSUserDefaults standardUserDefaults] 
    stringForKey:@"phoneString"];

    if (!([phoneString isEqualToString:@""])) {

        [[NSUserDefaults standardUserDefaults] setObject:@"" forKey:@"phoneString"];
        [[NSUserDefaults standardUserDefaults] synchronize];

        //check if the device can send text messages
        if(![MFMessageComposeViewController canSendText]) {
            UIAlertView * alert = [[UIAlertView alloc] initWithTitle:@"Error" 
            message:@"Your device cannot send text messages" delegate:nil 
            cancelButtonTitle:@"OK" otherButtonTitles:nil];
            [alert show];
            return;
        }

        //set receipients
        NSArray *recipients = [phoneString componentsSeparatedByString:@","];

        //set message text
        NSString *message = @"message";
        MFMessageComposeViewController *messageController = 
        [[MFMessageComposeViewController alloc] init];
        messageController.messageComposeDelegate = self;
        [messageController setRecipients:recipients];
        [messageController setBody:message];

        [self presentViewController:messageController animated:YES completion:nil]; 
    }
}

- (IBAction)button:(id)sender {

    SMContactsSelector *controller = [[SMContactsSelector alloc] 
    initWithNibName:@"SMContactsSelector" bundle:nil];
    controller.delegate = self;
    controller.requestData = DATA_CONTACT_TELEPHONE; // DATA_CONTACT_ID 
    DATA_CONTACT_EMAIL , DATA_CONTACT_TELEPHONE
    controller.showModal = YES; //Mandatory: YES or NO
    controller.showCheckButton = YES; //Mandatory: YES or NO

    [self presentModalViewController:controller animated:YES];
}

- (void)numberOfRowsSelected:(NSInteger)numberRows withData:(NSArray *)data 
andDataType:(DATA_CONTACT)type {

    if (type == DATA_CONTACT_TELEPHONE) {

        for (int i = 0; i < [data count]; i++) {

            NSString *str = [data objectAtIndex:i];                
            str = [str reformatTelephone];
            [phoneArray addObject:str];

            NSString *phoneStringAppended1 = [[NSUserDefaults standardUserDefaults] 
            stringForKey:@"phoneString"];
            NSString *phoneStringAppended2 = [phoneStringAppended1 
            stringByAppendingString: str];
            NSString *phoneString = [phoneStringAppended2 stringByAppendingString:@", 
            "];
            [[NSUserDefaults standardUserDefaults] setObject:phoneString 
            forKey:@"phoneString"];
            [[NSUserDefaults standardUserDefaults] synchronize];
        }
    }
}

#pragma mark - MFMailComposeViewControllerDelegate methods
- (void)messageComposeViewController:(MFMessageComposeViewController *)controller 
didFinishWithResult:(MessageComposeResult) result {
    switch (result) {
        case MessageComposeResultCancelled: break;
        case MessageComposeResultFailed: break;
        case MessageComposeResultSent: break;
        default: break;
    }
    [self dismissViewControllerAnimated:YES completion:nil];
}

@end

Answer 1

做一个 viewcontroller 单例是不行的。

将您需要的代码放在一个新类中，该类应该是单例的并且可以被所有 View Controller 访问。

我给你一个单例模式

SmsManager.h

#import <foundation/Foundation.h>

@interface SmsManager : NSObject {
    NSString *someProperty;
}

@property (nonatomic, retain) NSString *someProperty;

+ (id)sharedManager;

@end

短信管理器.m

#import "SmsManager.h"

@implementation SmsManager

@synthesize someProperty;

#pragma mark Singleton Methods

+ (id)sharedManager {
    static MyManager *sharedMyManager = nil;
    static dispatch_once_t onceToken;
    dispatch_once(&onceToken, ^{
        sharedMyManager = [[self alloc] init];
    });
    return sharedMyManager;
}

- (id)init {
  if (self = [super init]) {
      // initialization
  }
  return self;
}
@end

只需调用 SmsManager *smsManager = [SmsManager sharedInstance]; 任何你需要的地方