1. 首頁
  2. 問答
  3. Block for UIAlertViewDelegate

Block for UIAlertViewDelegate

2012-04-10 57 views
25

我很新的目標C和我只是想弄清楚，如果我可以使用塊或選擇器作爲UIAlertViewDelegate UIAlertView參數 - 哪個更合適？Block for UIAlertViewDelegate

我試過以下，但它只是不工作，所以我不知道如果我在正確的軌道上？

UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"Checked In" 
    message:responseString 
    delegate:^(UIAlertView * alertView, NSInteger buttonIndex) 
                { 
                 NSLog(@"Done!"); 
                } 
    cancelButtonTitle:@"OK" 
    otherButtonTitles: nil];

謝謝！

來源

2012-04-10 jb007

+0

蘋果不提供，但它是一個好主意。做到這一點的方法是一個子類。我會盡快發佈併發布。 – danh 2012-04-10 02:32:43

+0

danh的答案有效，但不支持多個按鈕。請參閱下面的答案。 – Besi 2012-08-25 16:44:08

回答

28

好主意。這裏是。就像警報視圖一樣，除了添加一個在警報解除時調用的block屬性。 （編輯 - 我已經簡化，因爲原來的答案該代碼這是我現在使用的項目。）

// AlertView.h 
// 

#import <UIKit/UIKit.h> 

@interface AlertView : UIAlertView 

@property (copy, nonatomic) void (^completion)(BOOL, NSInteger); 

- (id)initWithTitle:(NSString *)title message:(NSString *)message cancelButtonTitle:(NSString *)cancelButtonTitle otherButtonTitles:(NSArray *)otherButtonTitles; 

@end 

// 
// AlertView.m 

#import "AlertView.h" 

@interface AlertView() <UIAlertViewDelegate> 

@end 

@implementation AlertView 

- (id)initWithTitle:(NSString *)title message:(NSString *)message cancelButtonTitle:(NSString *)cancelButtonTitle otherButtonTitles:(NSArray *)otherButtonTitles { 

    self = [self initWithTitle:title message:message delegate:self cancelButtonTitle:cancelButtonTitle otherButtonTitles:nil]; 

    if (self) { 
     for (NSString *buttonTitle in otherButtonTitles) { 
      [self addButtonWithTitle:buttonTitle]; 
     } 
    } 
    return self; 
} 

- (void)alertView:(UIAlertView *)alertView didDismissWithButtonIndex:(NSInteger)buttonIndex { 

    if (self.completion) { 
     self.completion(buttonIndex==self.cancelButtonIndex, buttonIndex); 
     self.completion = nil; 
    } 
} 

@end

您可以擴展這個想法提供其他委託方法塊，但didDismiss是最常見的。

這樣稱呼它：

AlertView *alert = [[AlertView alloc] initWithTitle:@"Really Delete" message:@"Do you really want to delete everything?" cancelButtonTitle:@"Nevermind" otherButtonTitles:@[@"Yes"]]; 

alert.completion = ^(BOOL cancelled, NSInteger buttonIndex) { 
    if (!cancelled) { 
     [self deleteEverything]; 
    } 
}; 
[alert show];

來源

2012-04-10 02:52:39 danh

+2

下面是一個（完整）danh的想法實現：http://blog.mugunthkumar.com/coding/ios-code-block-based-uialertview-and-uiactionsheet/ – thelaws 2012-04-10 02:56:45

+0

您是否嘗試添加多個按鈕？ ':-)'見下面的答案。 – Besi 2012-08-25 16:43:20

+1

謝謝@Besi。更新了答案，以正確處理var args來合併代碼。 – danh 2012-08-25 17:05:09

1

這是對danh實現的更新，由於無法添加多個按鈕，因此這是不完整的。路過的va_list的功能是有點棘手:-)

所以，你可以做到這一點，爲了能夠將多個按鈕添加到UIAlertView：

- (id)initWithTitle:(NSString *)title message:(NSString *)message completion:(void (^)(NSInteger buttonIndex))completion cancelButtonTitle:(NSString *)cancelButtonTitle otherButtonTitles:(NSString *)otherButtonTitles, ... { 

    self = [super initWithTitle:title message:message delegate:self cancelButtonTitle:cancelButtonTitle otherButtonTitles:nil ]; 


    if(self){ 
     _completion = completion; 

     va_list _arguments; 
     va_start(_arguments, otherButtonTitles); 

     for (NSString *key = otherButtonTitles; key != nil; key = (__bridge NSString *)va_arg(_arguments, void *)) { 
       [self addButtonWithTitle:key]; 
     } 
     va_end(_arguments); 

    } 

    return self; 
}

更新：有可能將va_list傳遞給super的更好方法。我想提一下，對我來說va_list s有一些神祕的東西給他們:-)

來源

2012-08-25 16:42:19 Besi

+2

這很好。感謝va arg提示。我會編輯我的答案，以防這一錯過。 – danh 2012-08-25 16:59:23

-2

我不得不編輯調用示例一點，以停止編譯器錯誤。只是一個小小的調整和Xcode很高興。

UIAlertViewBlock *alert = [[UIAlertViewBlock alloc] initWithTitle:@"hi" 
                  message:@"hi there" 
                 completion:^(BOOL canceled,NSInteger buttonIndex) { 
                  NSLog(@"canceled=%d", canceled); 
                  NSLog(@"pressed=%d", buttonIndex); 
                 } 
               cancelButtonTitle:@"cancel" 
               otherButtonTitles:@"ok", nil]; 
[alert show];

來源

2012-10-31 02:41:31 nolimitsdude

0

只需使用REKit。它與BlocksKit類似，但功能更強大。

來源

2013-02-14 07:38:28 Kazki

1

真棒想法。我剛剛完成你的想法使用分類模式，沒有子類，直接調用UIAlertView。請按照下列步驟操作：

  1. 類別UIAlertView in。.h文件

    @interface UIAlertView (AlertWithBlock) 

    - (void (^)(UIAlertView *alertView, NSInteger buttonIndex))delegateBlock; 
    - (void)setDelegateBlock:(void (^)(UIAlertView *alertView, NSInteger buttonIndex))delegateBlock; 

    + (id)alertWithTitle:(NSString *)title message:(NSString *)message cancelButtonTitle:(NSString *)cancelButtonTitle otherButtonTitles:(NSArray *)otherButtonTitles delegate:(void (^)(UIAlertView *alertView, NSInteger buttonIndex))delegate; 

@end

  2. 在.m文件

    @implementation UIAlertView(AlertWithBlock) 

static char const *delegateBlockTagKey = "delegateBlockTagKey"; 

- (void (^)(UIAlertView *alertView, NSInteger buttonIndex))delegateBlock 
{ 
    return objc_getAssociatedObject(self, delegateBlockTagKey); 
} 

- (void)setDelegateBlock:(void (^)(UIAlertView *alertView, NSInteger buttonIndex))delegateBlock 
{ 
    objc_setAssociatedObject(self, delegateBlockTagKey, delegateBlock, OBJC_ASSOCIATION_RETAIN_NONATOMIC); 
} 

+ (id)alertWithTitle:(NSString *)title message:(NSString *)message cancelButtonTitle:(NSString *)cancelButtonTitle otherButtonTitles:(NSArray *)otherButtonTitles delegate:(void (^)(UIAlertView *alertView, NSInteger buttonIndex))delegate 
{ 
    UIAlertView *alert = [[UIAlertView alloc] initWithTitle:title message:message delegate:nil cancelButtonTitle:cancelButtonTitle otherButtonTitles:nil]; 
    alert.delegate = alert; 
    alert.delegateBlock = [delegate copy]; 

    for (NSString *buttonTitle in otherButtonTitles) 
    { 
     [alert addButtonWithTitle:buttonTitle]; 
    } 

    [alert show]; 

    return alert; 
} 

#pragma mark - Delegate 
-(void)alertView:(UIAlertView *)alertView clickedButtonAtIndex:(NSInteger)buttonIndex 
{ 
    if (alertView.delegateBlock) 
    { 
     alertView.delegateBlock(alertView, buttonIndex); 
    } 
} 

@end

  3. 這樣調用

    [UIAlertView alertWithTitle:@"Title" message:@"This is a message" cancelButtonTitle:@"Cancel" otherButtonTitles:@[@"Yes",@"No"] delegate:^(UIAlertView *alertView, NSInteger buttonIndex) { 
NSLog(@"Click at button index %ld", buttonIndex); 
}];

希望它能幫助。

來源

2015-01-07 08:36:18

+0

不錯！別忘了#import – Fracdroid 2015-09-11 19:39:50

1

我已經寫在斯威夫特的簡單延伸，希望它有幫助

import UIKit 

extension UIAlertView { 

    func show(completion: (alertView: UIAlertView, buttonIndex: Int) -> Void){ 
     self.delegate = AlertViewDelegate(completion: completion) 
     self.show() 
    } 

    class func showInput(title: String?, message: String?, cancellable: Bool, completion: (text: String?) -> Void){ 

     var strOK = NSLocalizedString("OK",comment: "OK") 
     var strCancel = NSLocalizedString("Cancel",comment: "Cancel") 
     var alert = UIAlertView(title: title, message: message, delegate: nil, cancelButtonTitle: cancellable ? strCancel : strOK) 
     alert.alertViewStyle = UIAlertViewStyle.PlainTextInput 
     if(cancellable) { 
      alert.addButtonWithTitle(strOK) 
     } 
     alert.show { (alertView, buttonIndex) -> Void in 
      if(cancellable && alertView.cancelButtonIndex == buttonIndex) { 
       completion(text: nil) 
       return 
      } 
      completion(text: alertView.textFieldAtIndex(0)?.text) 
     } 
    } 

    private class AlertViewDelegate : NSObject, UIAlertViewDelegate { 
     var completion : (alertView: UIAlertView, buttonIndex: Int) -> Void 
     var retainedSelf : NSObject? 
     init(completion: (UIAlertView, Int) -> Void) { 
      self.completion = completion 
      super.init() 

      self.retainedSelf = self 
     } 

     func alertView(alertView: UIAlertView, didDismissWithButtonIndex buttonIndex: Int) { 
      var retain = self 
      retain.retainedSelf = nil 
      retain.completion(alertView: alertView, buttonIndex: buttonIndex) 
     } 
    } 
}

來源

2015-02-06 03:16:50

2

一個蘋果文件說

一個UIAlertController對象顯示一條警告消息，用戶必須使用UIAlertController於這個方法。這個 類代替了顯示警報的 的UIActionSheet和U​​IAlertView類。在使用 動作和樣式配置警報控制器後，使用presentViewController：animated：completion：方法顯示它。

除了向用戶顯示消息之外，還可以將 操作與警報控制器相關聯，以便爲用戶提供一種響應方式。 對於使用addAction：方法添加的每個動作，警報控制器配置一個包含動作細節的按鈕。當用戶 點擊該動作時，警報控制器在創建動作對象時執行您提供的塊 。 Apple Docs.

UIAlertController* alert = [UIAlertController alertControllerWithTitle:@"My Alert" 


     message:@"This is an alert." 
            preferredStyle:UIAlertControllerStyleAlert]; 

    UIAlertAction* defaultAction = [UIAlertAction actionWithTitle:@"OK" style:UIAlertActionStyleDefault 
     handler:^(UIAlertAction * action) {}]; 

    [alert addAction:defaultAction]; 
    [self presentViewController:alert animated:YES completion:nil];

來源

2015-11-17 06:33:20

相關問題

 相關問題