Ios 将字符串从viewcontroller1传输到viewcontroller2，并在uiwebview的文本框中显示条形码扫描（字符串）

我在一个viewcontroller中有一个条形码扫描仪，在第二个viewcontroller中有一个uiwebview。如何获取在第二个viewcontroller的第一个viewcontroller捕获中创建的字符串。我尝试了几种方法，并用nslog对其进行了测试，但字符串值总是显示为（nil）。请帮我摆脱这一切

这是我的密码：

igViewController.m：

#import <AVFoundation/AVFoundation.h>
#import "igViewController.h"
#import "ViewController.h"


@interface igViewController () <AVCaptureMetadataOutputObjectsDelegate>
{
    AVCaptureSession *_session;
    AVCaptureDevice *_device;
    AVCaptureDeviceInput *_input;
    AVCaptureMetadataOutput *_output;
    AVCaptureVideoPreviewLayer *_prevLayer;

    UIView *_highlightView;
   }
@end

@implementation igViewController
@synthesize detectionString;
@synthesize delegate;
@synthesize thedetected;
- (void)viewDidLoad
{
    [super viewDidLoad];

    _highlightView = [[UIView alloc] init];
    _highlightView.autoresizingMask = UIViewAutoresizingFlexibleTopMargin|UIViewAutoresizingFlexibleLeftMargin|UIViewAutoresizingFlexibleRightMargin|UIViewAutoresizingFlexibleBottomMargin;
    _highlightView.layer.borderColor = [UIColor greenColor].CGColor;
    _highlightView.layer.borderWidth = 3;
    [self.view addSubview:_highlightView];

    _label = [[UILabel alloc] init];
    _label.frame = CGRectMake(0, self.view.bounds.size.height - 40, self.view.bounds.size.width, 40);
    _label.autoresizingMask = UIViewAutoresizingFlexibleTopMargin;
    _label.backgroundColor = [UIColor colorWithWhite:0.15 alpha:0.65];
    _label.textColor = [UIColor whiteColor];
    _label.textAlignment = NSTextAlignmentCenter;
    _label.text = @"(nichts)";
    [self.view addSubview:_label];

    _session = [[AVCaptureSession alloc] init];
    _device = [AVCaptureDevice defaultDeviceWithMediaType:AVMediaTypeVideo];
    NSError *error = nil;

    _input = [AVCaptureDeviceInput deviceInputWithDevice:_device error:&error];
    if (_input) {
        [_session addInput:_input];
    } else {
        NSLog(@"Error: %@", error);
    }

    _output = [[AVCaptureMetadataOutput alloc] init];
    [_output setMetadataObjectsDelegate:self queue:dispatch_get_main_queue()];
    [_session addOutput:_output];

    _output.metadataObjectTypes = [_output availableMetadataObjectTypes];

    _prevLayer = [AVCaptureVideoPreviewLayer layerWithSession:_session];
    _prevLayer.frame = self.view.bounds;
    _prevLayer.videoGravity = AVLayerVideoGravityResizeAspectFill;
    [self.view.layer addSublayer:_prevLayer];

    [_session startRunning];

    [self.view bringSubviewToFront:_highlightView];
    [self.view bringSubviewToFront:_label];


}
-(void) viewWillAppear:(BOOL)animated{
    if(detectionString!=nil){

        UIStoryboard *mainStoryboard = [UIStoryboard storyboardWithName:@"Main" bundle:nil];
        UIViewController *top = [UIApplication sharedApplication].keyWindow.rootViewController;

        UIViewController *vc = [mainStoryboard instantiateViewControllerWithIdentifier:@"Controller1"];
        [top presentViewController:vc animated:YES completion:nil];
    }

}


- (void)captureOutput:(AVCaptureOutput *)captureOutput didOutputMetadataObjects:(NSArray *)metadataObjects fromConnection:(AVCaptureConnection *)connection
{
    CGRect highlightViewRect = CGRectZero;
    AVMetadataMachineReadableCodeObject *barCodeObject;
    detectionString = nil;
    NSArray *barCodeTypes = @[AVMetadataObjectTypeUPCECode, AVMetadataObjectTypeCode39Code, AVMetadataObjectTypeCode39Mod43Code,
            AVMetadataObjectTypeEAN13Code, AVMetadataObjectTypeEAN8Code, AVMetadataObjectTypeCode93Code, AVMetadataObjectTypeCode128Code,
            AVMetadataObjectTypePDF417Code, AVMetadataObjectTypeQRCode, AVMetadataObjectTypeAztecCode];

    for (AVMetadataObject *metadata in metadataObjects) {
        for (NSString *type in barCodeTypes) {
            if ([metadata.type isEqualToString:type])
            {
                barCodeObject = (AVMetadataMachineReadableCodeObject *)[_prevLayer transformedMetadataObjectForMetadataObject:(AVMetadataMachineReadableCodeObject *)metadata];
                highlightViewRect = barCodeObject.bounds;
                detectionString = [(AVMetadataMachineReadableCodeObject *)metadata stringValue];
                setSomeNumber:[(AVMetadataMachineReadableCodeObject *)metadata stringValue];
                break;
            }
        }

        if (detectionString != nil)
        {
            _label.text = detectionString;
          // ViewController *otherViewController=[[ViewController alloc] init];

            UIStoryboard *mainStoryboard = [UIStoryboard storyboardWithName:@"Main" bundle:nil];
            UIViewController *vc = [mainStoryboard instantiateViewControllerWithIdentifier:@"Controller1"];
            ViewController *otherViewController=[[ViewController alloc] init];

            [otherViewController barcodeverarbeiten:detectionString];
            NSLog(@"detectionstringssssss %@", detectionString);

            [self presentViewController:vc animated:YES completion:nil];


            break;
        }
        else
            _label.text = @"(nichts)";
    }

    _highlightView.frame = highlightViewRect;
}
- (void)setSomeNumber:(NSString *)tempString {
    _label.text = tempString;
}
-(NSString *) thedetected{


    return _label.text;
}

@end

igViewController.h：

#import <UIKit/UIKit.h>
@class ViewController;
@interface igViewController : UIViewController{
    ViewController *delegate;
@public
UILabel *_label;
    NSString *detectionString;
    //NSString *tempString;

}
@property (nonatomic, strong)NSString *detectionString;
@property (nonatomic, strong) ViewController *delegate;
@property (nonatomic, strong) NSString *thedetected;
//@property (nonatomic, strong)NSString *tempString;
- (void)setSomeNumber:(NSString *)tempString;
@end

#import <UIKit/UIKit.h>
#import "FavoritenController.h"
@class igViewController;


@interface ViewController : UIViewController <UITextFieldDelegate, UIWebViewDelegate, UIActionSheetDelegate>

{


    UIWebView *Webseite;
    UIBarButtonItem *backButton;
    UIBarButtonItem *forwardButton;
    UITextField *textField;
    UIBarButtonItem *refreshButton;
    NSString* urlBeforeEditing;
    UIBarButtonItem *barcodescan;
    igViewController *otherViewController1;

    FavoritenController* favoritenController;
           /* ..*/

}
@property  (nonatomic, retain) IBOutlet UIBarButtonItem *barcodescan;

@property (nonatomic, strong)     igViewController *otherViewController1;
@property (nonatomic, retain) IBOutlet UITextField *textField;
@property (weak, nonatomic) IBOutlet UIBarButtonItem *onlinetauscher;
@property (nonatomic, retain) IBOutlet UIWebView *Webseite;
@property ( nonatomic, retain) IBOutlet UIBarButtonItem *refreshButton;
@property ( nonatomic, retain) IBOutlet UIBarButtonItem *backButton;
@property (nonatomic, retain) IBOutlet UIBarButtonItem *forwardButton;
- (IBAction)onlinetauscher:(UIBarButtonItem *)sender;

- (IBAction)pressRefresh:(UIBarButtonItem *)sender;
//- (IBAction)search:(id)sender;

- (IBAction)zeigeMedikamente:(id)sender;
- (IBAction)hinzufuegen:(id)sender;
- (void)barcodeverarbeiten:(NSString*)barcodepzn;
@end

#导入
@类视图控制器；
@接口igViewController:UIViewController{
视图控制器*委托；
@公开的
UILabel*\u标签；
NSString*检测字符串；
//NSString*tempString；
}
@属性（非原子，强）NSString*detectionString；
@属性（非原子，强）ViewController*委托；
@属性（非原子，强）NSString*被检测；
//@属性（非原子，强）NSString*tempString；
-（void）setSomenNumber:（NSString*）tempString；
@结束

ViewController.h：

#import <UIKit/UIKit.h>
@class ViewController;
@interface igViewController : UIViewController{
    ViewController *delegate;
@public
UILabel *_label;
    NSString *detectionString;
    //NSString *tempString;

}
@property (nonatomic, strong)NSString *detectionString;
@property (nonatomic, strong) ViewController *delegate;
@property (nonatomic, strong) NSString *thedetected;
//@property (nonatomic, strong)NSString *tempString;
- (void)setSomeNumber:(NSString *)tempString;
@end

#import <UIKit/UIKit.h>
#import "FavoritenController.h"
@class igViewController;


@interface ViewController : UIViewController <UITextFieldDelegate, UIWebViewDelegate, UIActionSheetDelegate>

{


    UIWebView *Webseite;
    UIBarButtonItem *backButton;
    UIBarButtonItem *forwardButton;
    UITextField *textField;
    UIBarButtonItem *refreshButton;
    NSString* urlBeforeEditing;
    UIBarButtonItem *barcodescan;
    igViewController *otherViewController1;

    FavoritenController* favoritenController;
           /* ..*/

}
@property  (nonatomic, retain) IBOutlet UIBarButtonItem *barcodescan;

@property (nonatomic, strong)     igViewController *otherViewController1;
@property (nonatomic, retain) IBOutlet UITextField *textField;
@property (weak, nonatomic) IBOutlet UIBarButtonItem *onlinetauscher;
@property (nonatomic, retain) IBOutlet UIWebView *Webseite;
@property ( nonatomic, retain) IBOutlet UIBarButtonItem *refreshButton;
@property ( nonatomic, retain) IBOutlet UIBarButtonItem *backButton;
@property (nonatomic, retain) IBOutlet UIBarButtonItem *forwardButton;
- (IBAction)onlinetauscher:(UIBarButtonItem *)sender;

- (IBAction)pressRefresh:(UIBarButtonItem *)sender;
//- (IBAction)search:(id)sender;

- (IBAction)zeigeMedikamente:(id)sender;
- (IBAction)hinzufuegen:(id)sender;
- (void)barcodeverarbeiten:(NSString*)barcodepzn;
@end

#导入
#导入“FavoriteController.h”
@类控制器；
@界面ViewController:UIViewController
{
UIWebView*Webseite；
UIBarButtonItem*后纽扣；
UIBarButtonItem*前进按钮；
UITextField*textField；
UIBarButtonItem*刷新按钮；
NSString*URLEBEFOREDITING；
UIBAButtonim*条码扫描；
igViewController*其他ViewController 1；
FavoriteController*FavoriteController；
/* ..*/
}
@属性（非原子，保留）IBUIBarbuttonItem*条码扫描；
@属性（非原子，强）igViewController*otherViewController1；
@属性（非原子，保留）IBOutlet UITextField*textField；
@性质（弱、非原子）IBUIBarbuttonite*onlinetauscher；
@属性（非原子，保留）IBUIWebView*Webseite；
@属性（非原子，保留）IBUIBarbuttonItem*刷新按钮；
@属性（非原子，保留）IBUIBarbuttonItem*backButton；
@属性（非原子，保留）IBUIBarbuttonItem*forwardButton；
-（iAction）onlinetauscher:（UIBarButtonItem*）发送方；
-（iAction）按刷新：（UIBarButtonItem*）发送方；
//-（iAction）搜索：（id）发件人；
-（iAction）zeigeMedikamente：（id）发送方；
-（iAction）hinzufuegen：（id）发送方；
-（无效）条形码VerarBeiten:（NSString*）条形码Pzn；
@结束

好的，现在开始工作了。我使用NSUserDefaults传递字符串，并在另一个ViewController中捕获它。干杯

您使用过该属性吗？请上传.h文件好的，我上传了.h文件