iOS：请求用户通过ActionSheet确认发送调度队列请求之前

Question

我还是iOS的新手，在我开发的应用程序中，当用户从外部源导入文件时出现此视图。我想有只执行导入的用户确认，在动作片， 的hiearchy如下之后：

• 用户从他的电子邮件的动产在应用程序中打开该文件。

• 然后，他切换到progressView（在导入过程中编程方式成为根视图）。

• 该过程完成并且默认rootview被设置回。

我想是询问用户是否真的想尽快导入为progressView表演，如果不是他要取消它（我不知道该怎么做）

谢谢你，

下面是函数：

- (void)handleImportURL:(NSURL *)url 
{ 



    __block JASidePanelController * controller = (JASidePanelController *)self.window.rootViewController; 

    // Show progress window 
    UIStoryboard * storyboard = [UIStoryboard storyboardWithName:@"MainStoryboard" bundle:nil]; 

    __block PVProgressViewController * progressController = [storyboard instantiateViewControllerWithIdentifier:@"kProgressViewController"]; 


    self.window.rootViewController = progressController; 
    // I think here somethings needs to be done with UIActionsheet  
    // Perform import operation 
    dispatch_async(dispatch_get_global_queue(0, 0), ^{ 

     NSError *outError; 
     NSString * csvString = [NSString stringWithContentsOfURL:url encoding:NSUTF8StringEncoding error:&outError]; 
     NSArray * array = [csvString csvRows]; 
     [[PVDatabaseController sharedController] importArray:array progressHandler:^(float progress) { 
      progressController.progressBar.progress = progress; 
     }]; 

     dispatch_async(dispatch_get_main_queue(), ^{ 
      self.window.rootViewController = controller; 
     }); 
    }); 
} 

更新：所以这是我试图用行动表做：

//First the function that calls the handleImport 
    -(BOOL) application:(UIApplication *)application openURL:(NSURL *)url sourceApplication:(NSString *)sourceApplication annotation:(id)annotation 
    { 
     // Handle CSV Import 
     if (url != nil && [url isFileURL]) { 
      [self handleImportURL:url]; 
      [self confirmImportAlert]; 

     } 
     return YES; 
    } 

//要显示动作片

- (void)confirmImportAlert { 
    UIActionSheet *myActionSheet = [[UIActionSheet alloc] initWithTitle:@"Proceed through Import?" delegate:self cancelButtonTitle:@"Cancel" destructiveButtonTitle:nil otherButtonTitles:@"Yes", @"Maybe", nil]; 
    [myActionSheet showInView: self.window]; 
} 

// what to do 
    -(void)actionSheet:(UIActionSheet *)actionSheet clickedButtonAtIndex:(NSInteger)buttonIndex{ 
     if(buttonIndex == 0){ 
      // Avoid Import 
     } 
     else{ 
      [self handleImportURL:_importURL]; 

      //initiate import 
     } 
    } 

更新2：所以我添加和更改的两种方法（I似乎无法调用应用程序代理的ActionSheetWilldismiss功能）：

-(void)actionSheet:(UIActionSheet *)actionSheet clickedButtonAtIndex:(NSInteger)buttonIndex{ 

    NSString *choice = [ actionSheet buttonTitleAtIndex:buttonIndex]; 
    if(buttonIndex == 0){ 
     //initiate import 
     [self handleImportURL:_importURL]; 
    } 
    else{ 
     //don't initiate import 
    } 
} 

//This methods creats the action sheet 
    - (void)confirmImportAlert { 
     // importActionSheet is a property in the appdelegate.h 

     if (!self.importActionSheet){ 
      UIActionSheet *myActionSheet = [[UIActionSheet alloc] initWithTitle:@"Proceed through Import?" delegate:self cancelButtonTitle:@"Cancel" destructiveButtonTitle:nil otherButtonTitles:@"Yes", nil]; 
      [myActionSheet showInView: self.window]; 
      myActionSheet.delegate = self; 

      self.importActionSheet = myActionSheet; 
     } 


    } 

并将调用导入的功能改为：

-(BOOL) application:(UIApplication *)application openURL:(NSURL *)url sourceApplication:(NSString *)sourceApplication annotation:(id)annotation 
{ 
    // Handle CSV Import 
    if (url != nil && [url isFileURL]) { 

     [self confirmImportAlert]; 
     //[self handleImportURL:url]; 



    } 
    return YES; 
} 

Answer 1

无论什么动作确实会触发-handleImportURL:的呼叫，而应创建一个UIActionSheet并显示它。

如果是例如按钮：

-(void)buttonTapped:(UIButton *)sender 
{ 
    // [self handleImportURL:someURL]; 
    UIActionSheet *actionSheet = [[UIActionSheet alloc] initWithTitle:nil 
                  delegate:self 
                cancelButtonTitle:@"Cancel" 
               destructiveButtonTitle:nil 
                otherButtonTitles:@"Confirm",nil]; 
    [actionSheet showInView:self.view]; 
} 

然后，你需要实现的委托方法：

-(void)actionSheet:(UIActionSheet *)actionSheet clickedButtonAtIndex:(NSInteger)buttonIndex 
{ 
    if (actionSheet.cancelButtonIndex != buttonIndex) { 
     [self handleImportURL:someURL]; 
    } 
} 

Answer 2

您应该在您的方法中创建并显示UIActionsheet，但不会执行任何当前的代码。当前代码中的所有代码都应该移到另一个方法中，并且应该调用该方法，如果用户点击了正确的按钮，请使用代理方法actionSheet:willDismissWithButtonIndex:。