我有一个名为“setTimeViewController”的视图控制器。我有另一个名为“setEventViewController”的视图控制器。用户点击 setTimeViewController 中表格中的一行,然后被发送到仅包含 UIPickerView 和保存按钮的 setEventViewController。当用户点击保存按钮时,它会将他们带回 setTimeViewController。
我希望从 setEventViewController 的选择器中选择的值能够从 setTimeViewController 访问,但返回(null)给我。我在 .h setEventViewController 中声明了一个 NSString *theVariable,这是我试图从另一个视图控制器检索并保留其属性的变量,但它仍然为空。
我已经从 setEventViewController 中的 viewDidDisappear 进行了测试(NSLog 变量),以查看当视图消失时它是否为空,但它可以正常工作。
这是我的代码,如果有人可以帮助我,我将永远感激不尽。谢谢!
setEventViewController.m
- (void)pickerView:(UIPickerView *)pickerView
didSelectRow:(NSInteger)row inComponent:(NSInteger)component
{
theVariable= [currentItemsInPicker objectAtIndex:row];
//[theVariable retain]; //Tried this as well but did not work
}
-(IBAction) Save
{
//simply dismisses the view controller back to setTimeViewController. Have also tried to set another NSString equal to theVariable but this did not work.
[self.navigationController popViewControllerAnimated:YES];
}
设置时间视图控制器
-(void) retrieveTheEvent
{
setEventViewController *eventViewController= [[setEventViewController alloc] init];
NSString *testString= eventViewController.theVariable;
NSLog (@"the event is %@", testString); //shows null
}