ios - 将数据传递给另一个 View Controller 不起作用

Question

我正在尝试将一个数组传递给另一个 View Controller 。但是，在接收方法已经执行之后，数据可以很好地到达那里。所以在接收方法中，我正在处理一个空数组。

我在这里发送。

   - (void)mapView:(GMSMapView *)mapView didTapInfoWindowOfMarker:(GMSMarker *)marker
  {
      UIStoryboard *mainStoryboard = [UIStoryboard storyboardWithName:@"MainStoryboard"
                                                         bundle: nil];
     UserProfileViewController *userProfileViewController = (UserProfileViewController *)[mainStoryboard instantiateViewControllerWithIdentifier:@"UserProfileViewController"];


     [userProfileViewController fetchMarkerData:marker.snippet nameOfUser:marker.title];

userProfileViewController.membersDetailArray   = self.membersArray; // This is what I am sending

     UINavigationController *nv = [[UINavigationController alloc]initWithRootViewController:userProfileViewController];
    [self.revealSideViewController popViewControllerWithNewCenterController:nv animated:YES];


 }

我在这里接收数组

  //This executes first and shows null ... the viewDidLoad NSLog output shows after this.
   -(void)fetchMarkerData:(NSString *)typeOfMarker nameOfUser:(NSString *)username
  {
   NSLog(@"members detail array in fetch marker data - %@ ", self.membersDetailArray); // shows null
   }
    - (void)viewDidLoad
   {
     [super viewDidLoad];
     NSLog(@"members detail array  in View Did Load- %@ ", self.membersDetailArray);//shows data  
   }

Answer 1

您正在将数据传递到以下方法:

-(void)fetchMarkerData:(NSString *)typeOfMarker nameOfUser:(NSString *)username {
    NSLog(@"members detail array in fetch marker data - %@ ", self.membersDetailArray); // shows null
}

但是您没有更新任何属性，例如 self.membersDetailArray(假设它填充了两个 typeOfMarker 和 username 对象.

此外，不要忘记初始化数组:

-(void)fetchMarkerData:(NSString *)typeOfMarker nameOfUser:(NSString *)username {
   self.membersDetailArray = @[typeOfMarker, username];
    NSLog(@"members detail array in fetch marker data - %@ ", self.membersDetailArray);
}

我不确定您希望如何存储数据(数组似乎不适合这两个对象，但至少可以解决您当前的 null 问题。