我是iOS编程的新手,我在视图控制器之间传递数据时遇到了麻烦。
我有一个视图控制器,它在地图视图上对注释进行地理编码,并将地址设置为注释视图的标题。注释视图有一个callout按钮,可以将另一个视图推送到具有标签的堆栈,我希望地理编码的地址显示为标签。这是一些代码:
这是我放下引脚的地方:
-(void)press:(UILongPressGestureRecognizer *)recognizer
{
CGPoint touchPoint = [recognizer locationInView:worldView];
CLLocationCoordinate2D touchMapCoordinate = [worldView convertPoint:touchPoint toCoordinateFromView:worldView];
geocoder = [[CLGeocoder alloc]init];
CLLocation *location = [[CLLocation alloc]initWithCoordinate:touchMapCoordinate
altitude:CLLocationDistanceMax
horizontalAccuracy:kCLLocationAccuracyBest
verticalAccuracy:kCLLocationAccuracyBest
timestamp:[NSDate date]];
[geocoder reverseGeocodeLocation:location
completionHandler:^(NSArray *placemarks, NSError *error) {
NSLog(@"reverseGeocoder:completionHandler: called");
if (error) {
NSLog(@"Geocoder failed with error: %@", error);
}
if (placemarks && placemarks.count > 0)
{
CLPlacemark *place = [placemarks objectAtIndex:0];
_address = [NSString stringWithFormat:@"%@ %@, %@ %@", [place subThoroughfare], [place thoroughfare], [place locality], [place administrativeArea]];
if (UIGestureRecognizerStateBegan == [recognizer state]) {
_addressPin = [[MapPoint alloc]initWithCoordinate:touchMapCoordinate
title:_address];
[worldView addAnnotation:_addressPin];
}
}
}];
}
以下是我希望地址显示的视图代码:
#import <UIKit/UIKit.h>
@class MapPoint;
@interface PinViewController : UIViewController <UINavigationControllerDelegate, UIImagePickerControllerDelegate,UITextFieldDelegate>
{
__weak IBOutlet UILabel *addressLabel;
}
@property (weak, nonatomic) IBOutlet UIImageView *imageView;
@property (strong, nonatomic) MapPoint *pin;
-(void)takePicture:(id)sender;
-(void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event;
@end
#import "PinViewController.h"
#import "MapPoint.h"
@interface PinViewController ()
@end
@implementation PinViewController
@synthesize imageView, pin;
-(void)viewWillAppear:(BOOL)animated
{
[super viewWillAppear:animated];
[addressLabel setText:[pin title]];
}
MapPoint类具有title属性和subtitle属性。当PinViewController被推到堆栈的顶部时,我尝试将标签的文本设置为引脚的标题,但标签不显示任何文本。有人能帮帮我,告诉我我错过了什么吗?非常感谢您的帮助。
答案 0 :(得分:2)
您必须为此问题分享更多代码块:)。而不是你必须更多地了解面向对象程序中的通信
您可以阅读有关在视图类之间传递数据的良好教程here
阅读在两个视图之间传递对象的最佳方法here
我在Developer.apple中找到了一份关于CommunicatingWithObjects
的好文档您还可以观看精彩视频here
答案 1 :(得分:1)
只需为标签创建属性,并从callout tapped方法
传递标签文本- (void)mapView:(MKMapView *)mapView annotationView:(MKPinAnnotationView *)view calloutAccessoryControlTapped:(UIControl *)control {
Details *det=[[Details alloc]init];
det.label.text=annotation.title;
[self.navigationController pushViewController:det animated:YES];
[det release];
}