重构ViewController（重复逻辑）

Question

在我的应用中，每个 ViewController 都有相同的逻辑。我想把它提取成一个 class.

这是我的案例。

每个 ViewController 都有多种发送 iMessage 的逻辑。 view controller的总数大概是50个。

这是第一个VC。

@interface FirstViewController : UIViewController <MFMessageComposeViewControllerDelegate>
....
- (void)sendMessage {
    MFMessageComposeViewController *mfvc = [[MFMessageComposeViewController alloc] init];
    .....
    [self presentViewController:mfvc animated:YES completion:^{}];
}

// Delegate
- (void)messageComposeViewController:(MFMessageComposeViewController *)controller 
             didFinishWithResult:(MessageComposeResult)result {
    [self dismissViewControllerAnimated:YES completion:^{}];
}

这是第二个VC。

@interface SecondViewController : UIViewController <MFMessageComposeViewControllerDelegate>
....
- (void)sendMessage {
    MFMessageComposeViewController *mfvc = [[MFMessageComposeViewController alloc] init];
    .....
    [self presentViewController:mfvc animated:YES completion:^{}];
}

// Delegate
- (void)messageComposeViewController:(MFMessageComposeViewController *)controller 
             didFinishWithResult:(MessageComposeResult)result {
    [self dismissViewControllerAnimated:YES completion:^{}];
}

大约有 50 个这样的视图控制器。

所以，我想按如下方式更改它。

@interface SendMessageHelper : XXX <MFMessageComposeViewControllerDelegate>
....
- (void)sendMessage:(NSString *messageBody) {
    // All the code that sends the iMessage include "presentViewController"
}

// Delegate
- (void)messageComposeViewController:(MFMessageComposeViewController *)controller 
                 didFinishWithResult:(MessageComposeResult)result {
    // Dismiss iMessage ViewController
}

///////////////////////////////////////////////////////////////////

@interface FirstViewController : UIViewController 
....
- (void)sendMessage {
    // Just call SendMessageHelper's sendMessage:
}

@interface SecondViewController : UIViewController 
....
- (void)sendMessage {
    // Just call SendMessageHelper's sendMessage:
}

....

@interface FiftiethViewController : UIViewController 
....
- (void)sendMessage {
    // Just call SendMessageHelper's sendMessage:
}

是否可以在单独的 classes 中处理所有 MFMessageComposeViewController 相关逻辑和委托？我该如何实施？

如果不行，请指教更好的方法

Answer 1

您有多种选择。您可以创建一个 UIViewController 的子类来实现您的方法，并使所有 50 个视图控制器成为该自定义子类的子类。

在这种情况下，在 UIViewController 上创建一个类别并添加这些方法可能会更好：

header:

@interface UIViewController (Messages);
  // Delegate
  - (void)messageComposeViewController:(MFMessageComposeViewController *) controller 
    didFinishWithResult:(MessageComposeResult)result;
@end

.m 文件：

@implementation UIViewController (Messages) {
  - (void)sendMessage {
      MFMessageComposeViewController *mfvc =[[MFMessageComposeViewController alloc] init];
      .....
      [self presentViewController:mfvc animated:YES completion:^{}];
  }

  // Delegate
  - (void)messageComposeViewController:(MFMessageComposeViewController *)controller 
    didFinishWithResult:(MessageComposeResult)result {
      [self dismissViewControllerAnimated:YES completion:^{}];
  }
@end

然后，如果您 #import header 文件，这些方法将可用。

重构ViewController（重复逻辑）

Refactoring ViewController(repetitive logic)

objective-c

uiviewcontroller

ios

mfmessagecomposeview

header:

.m 文件：