Question

我正在尝试将数组传递给另一个视图控制器。但是，在接收方法已经执行之后，数据到达那里很好。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];


 }

这里我收到了数组

  //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

您将数据传入以下方法：

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

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

另外，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（这两个对象似乎不适合使用数组，但至少可以解决当前null的问题。

Answer 2

在您发布的代码中，您正在调用

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

在您实际发送此行中的数组之前：

userProfileViewController.membersDetailArray   = self.membersArray;

只需切换这两行，fetchMarkerData:nameOfUser:应该具有self. membersDetailArray的正确值。

此外，您应该知道viewDidLoad在导航控制器要显示该视图之前不会运行，在您调用的情况下是

[self.revealSideViewController popViewControllerWithNewCenterController:nv animated:YES];

Answer 3

尝试替换这些行：

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

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

为此：

     //using the setter to pass your data before you call the fetchMarkerData
     [serProfileViewController setMembersDetailArray:self.membersArray]; // This is what I am sending 

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

将数据传递到另一个View Controller不起作用

3 个答案: