Question

从我的视图控制器中的NSString获取值到我的委托时遇到问题。问题是userId字符串。它在委托中出现错误

错误：访问未知的'userId'类方法

查看控制器代码段（profileViewController.m）

  -(void)parserDidEndDocument:(NSXMLParser *)parser
{
    NSDictionary *rowData = [self.userArray objectAtIndex:0];
    self.userId = [[NSMutableString alloc] initWithFormat:@"%@", [rowData objectForKey:@"id"]];

    NSLog(@"DONE PARSING DOCUMENT");
    NSLog(self.userId);

}

- (void)viewDidLoad
{
    self.title = @"Profile";
    interestingTags = [[NSSet alloc] initWithObjects: INTERESTING_TAG_NAMES];
    self.userArray = [[NSMutableArray alloc] init];
    [super viewDidLoad];
}

委托

    #import "profileViewController.h"

@implementation experimentAppDelegate

@synthesize window;
@synthesize rootController;

    -(void)goingOffline
{
    NSMutableData *data = [NSMutableData data]; 

    NSString *userID = profileViewController.userId;

    NSString *userString = [[NSString alloc] initWithFormat:@"id=%@", userID];

    //NSLog(nameString);
    //NSLog(numberString);

    [data appendData:[userString dataUsingEncoding:NSUTF8StringEncoding]];

    NSURL *url = [NSURL URLWithString:@"http://www.website.net/test.php"];
    NSMutableURLRequest *request = [NSMutableURLRequest requestWithURL:url];

    [request setHTTPMethod:@"POST"];
    [request setHTTPBody:data];

    NSURLResponse *response;
    NSError *err;
    NSData *responseData = [NSURLConnection sendSynchronousRequest:request returningResponse:&response error:&err];
    NSLog(@"responseData: %@", responseData); }

Answer 1

profileViewController是你的班级。要直接访问userId，应将其定义为

+ (NSString *) userId;

而不是，

- (NSString *) userId; // (or)
@property (nonatomic, copy) NSString * userId;

修改

由于profileViewController是标签栏控制器实例rootController中的一个视图控制器，您可以尝试获取此类profileViewController实例，

profileViewController * theController; NSArray * viewControllers = rootController.viewControllers; for ( UIViewController * viewController in viewControllers ) { if ( [viewController isMemberOfClass:[profileViewController class]] ) { theController = viewController; } } NSString * userID = theController.userId;

Answer 2

您需要将其设为实例变量。如果您有-(NSString *)，即使您将其导入另一个文件，也只能在该文件中访问它。如果您使用+(NSString *)，则不会再出现该错误。同样适用于空洞+(void)。祝你好运

将字符串从一个视图控制器放置到委托

2 个答案: