Question

我试图通过segue传递NSMutableString。 mutableString是MKPolygon的标题。我已经完成了像这样的mutableString：self.titleString = [[NSMutableString alloc] initWithString:polygon.title];

我不确定如何区分字符串：我现在有了这个：

-(void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender
{

    if([[segue identifier] isEqualToString:@"PickerViewController"])
    {
        NSLog(@"delegated");

        //Get the new view controller using [segue destinationViewController].
        PickerViewController *vc =[segue destinationViewController];
        vc.titleString = titleString;
    }
}

我在vc.titleString = titleString;时遇到错误。不知道如何在PickerViewController segue中设置String。错误：Property 'titleString' not found on object of type 'PickerViewController *'

PerformSegueWithIdentifier就是这个方法：

- (void)alertView:(UIAlertView *)alertView clickedButtonAtIndex:(NSInteger)buttonIndex
{
    //this would be the yes button or cancel
    if (buttonIndex == 0 ){

        NSLog(@"ButtonIndex Okay");
    }
    if (buttonIndex == 1) {

        [self performSegueWithIdentifier:@"PickerViewController" sender:self];
    }
}

我确实知道如何设置一个物体，但是对于弦乐，我不会理解它。帮助将非常感谢！

更新1：

我已导入PickerViewController.h文件中的ViewController.h。
我已使用vc.titleString = titleString;

vc.titleString = self.titleString;

我已将@property (strong,nonatomic) NSMutableString *titleString;添加到PickerViewController.h

没有运气。

更新2：

尝试了另一种方法来消除字符串：[(PickerViewController *)[segue destinationViewController] setTitleString:self.titleString];

得到错误：No visible @interface for 'PickerViewController' declares the selector 'setTitleString:'

ViewController.h文件：

@property (strong, nonatomic) NSMutableString *titleString;

ViewController.m文件：

@synthesize titleString; self.titleString = [[NSMutableString alloc]init];

PickerViewController.h文件：

@property (strong, nonatomic) NSMutableString *titleString;

PickerViewController.m文件：

@synthesize titleString; self.titleString = [[NSMutableString alloc]init];

似乎还没有认出titleString。

更新3：

仍然没有运气的字符串。

也许它与此有关：

NSMutableString正在循环中使用。循环检查是否有GPS，注释或触摸在MKPolygon内。每个多边形都有自己的颜色，在polygon.title中命名：见下面的代码*。所以String保存了所选的＆＃39;多边形标题。请参阅下面的循环：

其中一个多边形：

    CLLocationCoordinate2D roodPoly[2];
    roodPoly[0] = CLLocationCoordinate2DMake(52.372445351278294, 4.876454472541809);
    roodPoly[1] = CLLocationCoordinate2DMake(52.37288748990477, 4.878369569778442);

    MKPolygon *roodpoly = [MKPolygon polygonWithCoordinates:roodPoly count:2];
    roodpoly.title = @"red";
    [myMapView addOverlay:roodpoly];

一点循环：

            if(CGPathContainsPoint(mpr , NULL, mapPointAsCGP, FALSE)){

                NSLog(@"Coordinate %f,%f is in polygon %@", tapCoord.latitude, tapCoord.longitude, polygon.title);

                self.titleString = [[NSMutableString alloc] initWithString:polygon.title];
                self.subtitleString = [[NSMutableString alloc] initWithString:polygon.subtitle];

                alertView = [[UIAlertView alloc]initWithTitle:@"Found it" message:subtitleString delegate:self cancelButtonTitle:@"Cancel" otherButtonTitles:@"Stel notificatie in", nil];
                [alertView show];

                NSLog(@"The color of the Polygram is: %@", titleString);

            }

            CGPathRelease(mpr);
        }
    }
}

我认为这可能会导致找不到字符串的问题：（

Answer 1

在你的＆＃34; PickerViewController.h＆＃34;应该是这样的：

#import <UIKit/UIKit.h>

@interface PickerViewController : UIViewController

@property (strong,nonatomic) NSMutableString * titleString;

@end

在你的＆＃34; ViewController.m＆＃34;文件：

#import "ViewController.h"
#import "PickerViewController.h"

@interface ViewController ()

@end

@implementation ViewController

- (void)viewDidLoad
{
    [super viewDidLoad];
    // Do any additional setup after loading the view, typically from a nib.
}

-(void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender{
    [(PickerViewController *) [segue destinationViewController] setTitleString:self.titleString];
}
@end

这里工作正常..

希望有所帮助：）

通过Segue传递字符串

1 个答案: