點擊按鈕后調用方法完成塊

Question

我在單獨的類中創建了一個帶按鈕的popupView。 當在彈出視圖中點擊按鈕時，它應該進入完成處理程序內。

例。 UIAlertAction actionWithTitle：...：handler ^ {}; 這將使用OK按鈕打開alertView。 當點擊按鈕時，我將在完成處理程序中工作。

是否可以這樣創建，如果可以的話，如何在Objective-C中創建它。

我知道如何使用@protocol創建和設置類協議並調用方法。 我需要為許多視圖控制器使用此類，所以我不想在實現該類的任何地方調用協議方法。

Answer 1

您可以嘗試使用塊（目標C）

創建一個帶塊的屬性，在創建彈出視圖的地方編寫以下代碼。

@property (nonatomic, strong) void (^actionHandler)(void);

在操作按鈕中-

- (IBAction)doneButtonAction:(id)sender {
     _actionHandler();
}

//當顯示popView時，您定義處理程序

[popView setActionHandler:^{
        // DO Whatever you want, you just need to write this whenever you show pop view, rest code only once. 
}];

Answer 2

使用完成處理程序創建函數

-迅捷3-

func action(completion:@escaping (_:Bool) -> Void) {

}

action { (success) in

}

-目標C-

- (void)action:(void (^)(bool success))completionHandler {

}

[self action:^(bool success) {

}];

Answer 3

我創建了兩個單獨的類，ViewController.h和PopupViewController.h

請查看代碼：

ViewController.h

#import <UIKit/UIKit.h>

@interface ViewController : UIViewController


@end

ViewController.m

#import "ViewController.h"
#import "PopupViewController.h"

@interface ViewController ()

@end

@implementation ViewController

- (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.
}

-(IBAction)btnOkPressed:(id)sender
{
    PopupViewController *master=[PopupViewController sharedInstance];
    [self presentViewController:master animated:YES completion:^{

    }];
    [master callCompletion:^(NSString *str) {
        NSLog(@"%@",str);
        [master dismissViewControllerAnimated:YES completion:^{

        }];
    }];
}


@end

PopupViewController.h

#import <UIKit/UIKit.h>

typedef void(^Completionhandler)(NSString* str);

@interface PopupViewController : UIViewController

+(PopupViewController*)sharedInstance;
-(void)callCompletion:(Completionhandler)handler;

@end

PopupViewController.m

#import "PopupViewController.h"

@interface PopupViewController ()
{
    @private
    Completionhandler _myHandler;
}

@end

@implementation PopupViewController

+(PopupViewController*)sharedInstance
{
    static PopupViewController *popup=nil;
    static dispatch_once_t onceToken;
    dispatch_once(&onceToken, ^{
        popup = [[PopupViewController alloc] initWithNibName:@"PopupViewController" bundle:nil];
    });
    return popup;
}

- (void)viewDidLoad {
    [super viewDidLoad];
    // Do any additional setup after loading the view.
}

- (void)didReceiveMemoryWarning {
    [super didReceiveMemoryWarning];
    // Dispose of any resources that can be recreated.
}

-(IBAction)btnOkPressed:(id)sender
{
    _myHandler(@"test msg");
}

-(void)callCompletion:(Completionhandler)handler
{
    _myHandler = handler;
}

@end

我希望你能得到答案，如果您有任何疑問，請隨時問我.. :)